Date: Mon, 27 Mar 2000 12:34:17 -0800 I just got off the phone with Turbonetics and Turbo City
Basically Turbonetics gave me a price of about $702 to rebuild both turbos,
which include; (forgot to ask about warranty)
$175 each turbo blueprinting, balancing, VSR, Five Day Turnaround. But I have to send it through a dealer, which Tri-point
is and it shouldn't alter the price. I haven't confirmed with Tri-Point yet.
Turbo City gave me a price of 588 for both turbos same as above but they
don't do VSR but use other methods of tunning for vibration and do not clip
compressor wheels for adding the extra air flow. One Day Turnaround. They
have a 3 month/3,000 mile warranty.
I am not in a rush because I have a daily driver and for what I care please
take your time!! I've had bad experiences because of me rushing my mechanic
on a clutch job.
I called Mazdatrix and they really recommend Turbo City. They send all their
Turbo rebuild jobs over to them and to their knowledge have no complaints.
________________
Date: Wed, 09 Jun 1999 02:48:32 -0400 I called some shops today and got info on the upgrades available for the
sequential (stock) turbos. I will be out of town for a few weeks, but I wanted
to get a quick list together for those that were interested.
There are a few more options out there, but this should be a decent
survey of what is available. I don't know what I want yet. I welcome any
corrections, comments or additions.
________________
Date: Wed, 30 Jun 1999 02:20:05 -0400 I have been looking at upgraded sequential turbos lately. I heard from a
lot of people that the shafts tend to snap with bigger compressor
wheels. Some say this is only a problem when you run 18 psi, but others
said it is a general problem which I assume can happen at lower boost
levels. Any testimonials out there to help us understand?
Rotary Performance Online has an upgrade that uses
Garrett compressors AND shafts. This sounds like a durable upgrade, but
it is expensive ($3100). RPO seems to be the only vendor that offers
such an upgrade.
Clipping the exhaust turbines means less backpressure for more power but
also more lag. How much? I don't know.
Personally, I am leaning toward saving money and getting a standard
rebuild. I think you really have to decide what you want out of the car
before you spend a lot of money on a fancy sequential upgrade or a
single turbo setup. I am not totally sure what I want yet.
Here's a short list of what is available:
* Various levels of warranty
* A large range of prices for what seems like the same thing
________________
Date: Thu, 6 Jan 2000 11:50:28 -1000 (HST) It really depends on what your looking for. Maximum responsiveness, enhanced
reliability, maximum bang for the buck or ultimate power potential.
I'm not sure but I believe that the upgrades only flow at most 20% better
than the stockers (not really the same thing as efficientcy but will have to
do). Not much gain there compared to something like a T-66 or T-78 single
with nice big exhaust manifold . A major weakness of the stock setup is of
course the restrictive and fragile exhaust manifold and turbo housing. Ever
look at them? Fine for 14 lbs of boost on a near stock motor expected to put
out no more than 360 RW HP (maybe 385 if you go non seq, hogg out the
manifolds and pay very special attention to your fuel system). Still
ultimately hopeless for really high flow situations when looking for 450+
hp. Too much back pressure for really efficient high boost no matter how
good the upgraded turbos are. I certainly would strongly consider sticking
with the stockers without the upgrades if I just wanted 360 hp. and a very
responsive street car for a reasonable investment. If the seq. transition
bothered me (and believe me it can be quite dangerous at 360 hp) you can
still just go non seq. The upgrades though seem just to little bang for the
buck, being as pricy as a good single but with less ultimate potential stuck
with the crappy OEM manifold/housing. And, unless you go non seq. your still
stuck with the rat's nest of stupid vacume lines, control actuators,
pre-control actuators/valves, solenoids etc.
A most interesting comparason would be between upgraded OEM non sequential
turbos vs a well set up dual BB single system. Hmmmm, all things considered
I'd bet on the single to be just (or darn near) as responsive, price
competative and with more maximum potential.
Date: Tue, 18 Jan 2000 15:06:15 -0500 (EST) > What is the purpose of upgrading the turbocharger, it's efficiency in There are three things that trade off against each other with a turbo.
Lag, airflow (measured in CFM), and boost. You can improve any of these
but the other two suffer. If you want to improve all three, then your
turbo must work harder, which reduces its efficiency. This translates
into increased temperature and more "effort" expended to produce a given
amount of boost. Turbos have an efficiency range in which they work very
well within certain boost and CFM parameters, but rapidly become very
inefficient outside those parameters. Typically, a bigger turbo will have
an efficiency range better suited to high boost, high flow.
> How can a turbocharger help increase horsepower other than by increase By increasing the airflow. Improvements in VE (such as by opening the
intake and exhaust, or by porting) and higher RPM operation require more
airflow. Sometimes they happen together. For example, a street port not
only improves efficiency, but also moves the HP peak up in the rev range.
This requires the turbo to blow more air on both counts.
> What are the components of a turbocharger anyway, compressor wheel, Mostly the important components are the compressor/impeller, the turbine,
and the housing. The housing determines how fast the air blows into and
out of the system, (a smaller housing accelerates the air in the turbo
making it spool faster, but also provides restriction). A smaller housing
is better for low (engine) RPM operation and worse for high RPM, even with
the same compressor and turbine. The shaft connects the compressor to the
turbine but as long as it doesn't fail it makes no difference from a
performance standpoint. The turbine and the compressor sizing determines
the maximum output, but larger means more lag and more difficult boost
control.
> either by replacing parts, or replacing the whole thing?
Typically the whole turbo is replaced, although it is (theoretically)
possible to change the parts individually.
Editor's note: See the section above on
upgrading the stock turbos
for more info on what parts are typically upgraded or replaced. --Steve
_______________
Date: Tue, 18 Jan 2000 21:16:36 -0500 Three reasons to upgrade the turbochargers on the 3rd Gen. Efficiency,
reliability, and power. That's the simple answer. Let me try a brief
explanation.
Efficiency, Power
All turbochargers present compromises between flow capacity and turbo lag.
The larger the turbo, the slower it is to spool, but the more air it can
flow when up to speed. The FD's units were sized for maximum response while
meeting the flow requirements of the engine at the targeted power level.
Each compressor has an area of greatest efficiency (adiabatic), in which it
can compress/flow a given volume of air per unit time without introducing
excessive heat in the process. This is defined graphically by a compressor
map, and is primarily a function of compressor design, size, and rotation
speed. Increase flow to obtain more power on the FD by adding intake,
exhaust, intercooler, etc.and you will rapidly find yourself outside the
stock turbocharger's efficiency sweetspot, since the compressor must spin
faster to maintain the same intake pressure. The main detriment in the
11-13 psi range is that the compressor outlet temps become extremely hot,
on the order of 300F, which places additional thermal stress on the engine,
and may increase detonation risk. Also, in sequential twin-turbo cars, the
secondary unit is accelerated to a high speed in a closed circuit chamber
(surge) to prevent a drop in compressor speed and flow at the switchover
point when the compressor comes under load, which would cause a dip in
power and torque (the famous dip we all notice in the dyno plots). This
power dip, already slightly noticeable in stock cars, becomes much worse in
modded cars, since the turbo is already operating at its pre-spin speed
just to maintain a given level of boost, and becomes extremely resistant to
overspeeding.
Over 14 psi on sequential twin cars with fully open intake and exhaust, the
stock turbos actually cause a restriction in the intake path which limit
the effective power you can make. Can you upgrade to larger compressor
wheels? Sure, but shaft failures often accompany this mod, because the
stock shaft was not sized for that weight wheel. You can also clip the
turbine wheels for better flow at high speed, but low speed response may be
impacted. The switchover problem does not go away.
So, the guys who want BIG power (360 RWHP +) go to a single, large turbo.
And they throw in a whole new fuel system just for kicks (also happens to
help keep the engine alive). What they gain in power, they lose in
response. Drag racers don't care about this because they can pre-load the
turbo off the line, use NOS, or some combination of the two, and benefit
from tremendous increases in top-end power. Road racers (especially those
who drive tight courses) do care, because the car is either way too fast or
way too slow (just like the old Porsche 930 Turbos). For them, nothing
beats the response of the stock sequential twins.
In terms of reliability, the stock system is extremely complex, not very
durable, and most people have no clue how to troubleshoot it. The nest of
vacuum hoses and solenoids has driven many an at-home mechanic to the brink
of suicide. Even when it does work, it is not entirely consistent in its
operation, to put it politely. So you may be left wondering where your
second turbo is as you watch Jim's Supra blow past you (probably would
anyway). Bad as that is, increasing boost on the sequential system seems to
present problems for piggyback boost controllers which are totally beyond
the scope of this post (to the extent the post is not already beyond its
own scope). The PFS-PMC seems finally to have overcome the majority of
these problems but it has taken six years! The solution to this melodrama
for some, is to go single turbo: one wastegate, one boost pattern, no
vacuum nest, no solenoids, theoretically easy fuel map etc. So say the
single turbo guys. And their results at the strip corroborate this view.
Me, I like the twisties, so I will stay twin-sequential for now, for the
response. My next upgrade will be either a 20B twin-sequential, or 5.7
liters of V-8 power in something that looks sorta like an RX-7 from the
front ;-)
_______________
Date: Tue, 18 Jan 2000 21:49:41 -0800 Let me start by saying that everyone who intends to modify a
turbo-charged car should buy, read, and refer to the book
_Maximum_Boost_ by Corky Bell. It is a little dated, but the
fundamentals are still the same and this book is a very readable and
practical introduction to all things 'turbo'. Highly recommended. Buy it
at http://www.amazon.com/.
> What is the purpose of upgrading the turbocharger, it's efficiency in Most turbo upgrades are performed to increase peak power, often at the
expense of low end power. The average turbo upgrade increases lag. It is
up to the purchaser to decide what they want to optimize. There is no
turbo that will offer the least lag and the highest maximum power, it is
always a balance. Some turbos are "better" than others in that they
offer a little more of both than a less good alternative.
> How can a turbocharger help increase horsepower other than by increase the There are several ways this can happen. First, you might actually reduce
lag and increase low end power if you select a turbo that can create
high boost pressure at a low rate of flow. But usually, just as you
suggest, you get a turbo that can produce more boost at high RPM (high
flow). Another important factor is compressor efficiency. Compressor
efficiency is a measure of how much the turbo heats the air at a given
boost and flow rate. Greater efficiency (less heating) gives you greater
power as the air that comes out of the turbo is more dense with air
molecules. It is like driving your car on a cold night -- it makes more
power. It also does not have to work as hard to create that level of
boost, so you will have less backpressure being caused by the turbo. We
all know how important a free-flowing exhaust system is on a rotary, and
having an efficient turbo system is especially beneficial for the same
reason.
> What are the components of a turbocharger anyway, compressor wheel, shaft? You basically have the turbine side that is driven by the exhaust
gasses, a shaft and bearing in the middle, and a compressor side that
compresses your intake air on the other side. The turbine and compressor
parts include both a wheel and a housing which give them their
performance characteristics. The shaft's diameter is important in the
case of the third gen, because it is too small to support large
compressor wheels. Most turbos use a regular bearing, but ball bearing
turbos offer reduced lag and perhaps increased reliability.
_______________
Date: Fri, 13 Mar 1998 00:07:17 -0500 You might want to check out Turbo City
out in CA. I've recently sent for a catalogue and if I remember correctly
(I'm at work now, so I can't look it up), they have replacement
"cartridges", rebuild kits, rebuilt turbos, and I think even new turbos
for the 3rd gens. They also have rebuild kits and rebuilt turbos for the
2nd gens for all of those who may be interested. Of course, they have
some aftermarket stuff too.
_________________
Date: Wed, 28 Apr 1999 23:49:02 -0500 You can use any of the following turbos I listed below:
T62-1, T60-1, TS04, T66 W/ceramic ball bearing
Any of those turbo should work well on rx7. The only reason I pick T62-1 is
that it has a relative good flow rate. T60-1 will give you better low end
response(Marcus from Apex racing has dynoed 380rwhp@12psi with this turbo).
T66 will give you high end horsepower (actually has a better response than
the T62-1 if you have the ceramic ball bearing). My friend Brent Bucher
dynoed at 399rwhp@17psi using this turbo on a stock motor. He gets full
boost at 4krpm vs. 4.5krpm on my turbo.
The only main difference between the
setup between my car and the guys i mention above is that I'm still using the
stock injectors but both of them are running stock motor and 3.5in exhaust
system. I guess there're some gain for running a bigger exhaust system. The
reason why I decided to use the T62-1 is because I'm cheap and didn't want to
spend too much money for trial and error not knowing what to expect. It's
really up to you as to what goals you want to achieve.
BTW, I wouldn't recommend anything smaller than .96 exhaust A/R ratio.
__________________
Jay (styk33@yahoo.com) forwarded this from the Supra mailing list sot there will be
differences, but it is a good place to start looking for info.
Date: Tue, 7 Mar 2000 23:35:51 EST Since a lot of people have been asking this question, I summarized the
most common turbo kits in this email.
________________
From: Rich (rich@uprd.com) Just wanted to let you know that the UPRD Supra is using twin HKS 3037S
turbos, not the 2540's. The 2540's could never put out the horsepower we are
making (921 rwhp, no NOS). Tons of information tho, great site. Keep up the
good work, and look for us in the 9's real soon with a stock chassis, stock
transmission! Here we come, Ari!
Richard Schroeck ________________
Date: Fri, 21 Apr 2000 10:24:29 -0700 Single (turbos):
T04E
For the street, the To4E is a great turbo for the FD. Massive, flat torque
and a little more power than the sequentials make for a fun street/circuit
car. I spent a week with an FD with a T04E and it was pure fun. Expect
350-410 hp with a correctly sized T04E.
RX6
Another good combination for the street/circuit is the RX-6. As for
durability, the RX-6 is absolutely bulletproof. The RX-6 was and still is
used in many forms of racing including LeMans, Japanese JGTCC, and even came
stock on the Ferrari F40. It's so strong that you don't need a blow off
valve. On our 1100 hp syline, we use two RX-6s at 2.1kg/cm2 and we do nto
use blow off valves. This turbo is STRONG. However, Apex seals flying out
the exhaust ports on a rotary will still break turbine wheels. This is not
going to be a big power turbo because the turbine section in smaller than
your average Garrett, but the compressor side is larger than your average
Garrett. Expect 370-450 hp.
T04X
This is an XS Engineering propietary turbo that they use on a lot of the
drag Hondas. It seems to work well on a Rotary as well. I drove a car with
a T04X two weeks ago and it kicked some serious a$$ with a broad powerband
and rockin' top end. It dyno'd at 435 to the wheels on pump gas.
Please note that hp ratings are for 92 octane pump gas.
Just thought I'd share a few of my single turbo experiences.
________________
Date: Mon, 24 Apr 2000 13:31:29 +0200 I am going this route. Before I decided to do so, I made back-to-back
comparisons with the stock turbos in sequential and non-sequential setup in
all kinds of driving conditions (city, country road, race track, German
Autobahn).
During the winter I rebuilt/ported/balanced the engine and also modified the
lubrication system.
Next week, the engine goes on a dynamometer for proper turbo matching and
ECU mapping.
We have a few turbochargers lined up for testing:
The flow capacity of these units is in the 380 - 450hp range. Let's see
which one we decide one. I prefer driveability and low- and midrange punch
over the top figures (which mostly seem to serve for bragging on this list).
I am also going a new route with the engine management system. A specialist
company in England built an ECU to our specifications.
________________
Date: Sun, 19 Mar 2000 10:31:12 -0500 A few people have asked what kind of money goes into putting a single turbo
in their Rx7. Here is a breakdown of what you should expect to spend when
going single. This is assuming that you're already modified to the max.
T-78 Turbo Kit: includes turbo, downpipe, wastegate and all fittings to bolt
up to the stock intercooler. This kit is very complete. One modification
that we ran into was we had to grind down and cap the EGR valve. It stuck
out to far for the downpipe to fit. PRICE: $3500 (depending where you get
it from)
When checking around for fuel requirements for a single turbo, the overall
consensus was to run larger 2ndary injectors. I replaced the 850cc with
1200cc. PRICE: $400
I was running a M2 computer, so I had to replace that with something that
will control fuel/timing. I went with the PMS, but probably should have gone
with the Haltech instead.
PRICE: $1200
Labor: Totally depends on labor rates and how competent your tech is. I
would figure $1000 to install. That may be a little high, but figure
somewhere around there.
Total: $6100 Give or take a few bucks. Sounds expensive, but faster and
cheaper than buying a Viper. :)
________________
Date: Thu, 20 Apr 2000 01:03:57 -0700 I just helped my friend Dean install the new Apex'i Isamu single turbo
upgrade kit into his car tonight. Overall, it's a very nice looking
package, but just a word of caution for those of you contemplating
purchasing the kit:
________________
Date: Thu, 20 Apr 2000 09:42:41 -0700 One word of advice on the Isamu turbo kit. Bolt all brackets and mounts
together as the instructions state. If you do not bolt the wastegate to the
downpipe, the wastegate pipe or the downpipe WILL CRACK. This is because
stainless steel does not take too well to contraction/expansion with
vibration. However, stainless steel does look very nice and does not
corrode.
The bracket for the wastegate and downpipe does fit. I have tested the
Isamu kit on three different FDs to ensure perfect fitment.
________________
Date: Thu, 20 Apr 2000 11:44:31 -0400 The HKS T04E kit lets you retain the airpump. It's a very nice and complete
kit. One of my friends has that kit and the car is very responsive with
minimal lag. We have not dynoed it yet, so not sure the power gains over the
stock turbos.
________________
Date: Mon, 6 Mar 2000 01:07:09 -0600 They are several factors that need to be looked at such as:
You could actually run single turbo with a little trickery on your stock ECU
and a couple aftermarket controllers but that will be totally stupid. I'd
suggest talking to couple retailers and map out a course first, going single
turbo is a huge task. My friend and I are in the process of getting of the
stuff needed to go single turbo on his car. We rebuilt his motor w/ 2mm
seals, mild port and had the housings cryo treated and decided to go with
M2's single turbo kit which actually comes with the manifold and downpipe.
There are several different routes to go in regard to fuel
management..personally I suggest the Haltec setup that Rotary Performance
sells, I'm sure the Electromotive system is nice but I don't like the way
it's setup. The Motec is very expensive and I still haven't found a car that
is streetable using that system. Give Brain Richards a call at M2, he's
helped us a lot.
________________
Date: Tue, 29 Jan 2002 18:21:26 -0600 Actually yes Trev and I designed and built an independent twin setup. It's
actually pretty ideal and is still on my car right now (minus the turbo's). It's
a thick stainless plate, 1/2 inch I think attaching to the block and exhaust
ports. From there we used Inconel tubing directly from the exhaust port to each
turbo independently with independent external wastegates venting back into the
exhaust stream after the turbos. Each turbo was a ceramic ball bearing T4 60-1
compressor with a T3 exhaust side. I forget the A/R ratio on the exhaust side
off the top of my head. Had 2 or 3 exhaust housing of different ratios we could
swap out pretty easily depending on which aspect of spool and flow we wanted.
All of it came back together into a single 3 inch pipe bolting into where the
normal Midpipe would connect.
The initial testing was hindered because of a wee minor problem with a
compressor bypass valve. The valve was stuck open on one of the turbo's creating
a 3/4 inch diameter boost leak : ). Even with that enormous leak the car made
20 psi boost easily. Of course it didn't give any real indicator of how much
power it would produce with that leak and did severe damage to the turbine,
actually burning the turbine wheel apart.
Anyway I eventually did find the problem with the compressor bypass (blowoff)
valve problem and was able to simply plug the valve for some initial real
testing. Although I only got a few tests off before the burned turbine warped
the shaft. Keep in mind this was not on a stock car. It was a heavily bridge
ported motor with long exhaust port timing, an enormous fuel system 4 850cc's
and 2 550's with dash 10 supply lines and an SX fuel pump using C16 116 octane
leaded gas. Having had the car run 11.1 on a stock motor with upgraded stock
turbos before, I had a good idea of how power felt for that. The tests I got
after plugging the CBV were absolutely phenomenal. I've never felt torque even
remotely close to that in a rotary before and the power was just nuts. I reached
20 psi of boost by approximately 4k rpm. By applying full throttle even at 50
odd mph the tires would start to spin on Hoosier 305/40 17's.
The next night I went out to test it the shaft warped and I got the nasty
screech of compressor wheel starting to scrape the housing etc. When I pulled
the turbo's off and took a peek I got to see that the 3/4inch leak for a few
weeks was just way too much for that turbo, the ends of that turbine were burned
off etc. The other turbo actually looked pretty good.
That was towards the end of the season and where the real epic began : ). I sent
the turbo's off to Turbonetics to be rebuilt in no real hurry since winter was
coming before they'd likely be done. So I went back to normal winter stuff like
doing real work etc. and finally the turbo's are done and shipped to me. So I
write out the company check and the jovial UPS man show's up at the office,
errrr whoops Turbonetics forgot to mark the box as Company check okay. Sigh, it
get's shipped back to Turbonetics. Fine send them again and make sure you list
Company check as okay. Turbonetics of course says, so sorry of course I won't
forget to mark that this time and I'll send them again. A month or two goes by
and eventually I get a tag from UPS that the turbos are here, AGAIN. Another
voided check later I see they forgot to list company check as okay again.
Sheesh, come back tomorrow I'll just get cash for it in the morning. Stop at the
bank grab cash for it and come into work. UPS man arrives, here's the correct
cash amount, thank you. Errr uh oh sorry we changed our policy just recently
and can't accept cash anymore. So the Turbo's go back to Turbonetics again. So I
eventually call Turbonetics to ask Ola what's going on with this, I'll just send
you a check before you ship this time or put it on a personal credit card
instead. Oh we're sorry Ola is no longer with us. Okay so let me talk to whoever
else I should so I can get my turbo's back please. I'm starting to forget some
names now since there's been about 4 or 5 of them. Each time I reach someone
they have no clue where the turbos are and tell me they'll call me back when
they find them and the invoice etc. Of course like you'd expect it got lost in
the shuffle and I'd have to call back a few weeks later to see if they'd found
them etc.Eventually they're found but they can't find the invoice amount for
them. I'll call you right back after I find it so we can take care of this.
Whoops the guy that found them is no longer working here now at my next call.
Same drill all over again. I'm not sure where they are etc. I'll call you back
after I find them. This ridiculous drill goes on for about 1 1/2 years over at
least 4 different people from the initial sales guy I brought them from, Ola.
Eventually this last spring I'm completely fed up with this and say screw it, I
send a check to Turbonetics for about $100 over the approximate amount and a
cover letter explaining all the garbage that's been going on so that when they
do finally find everything the hoops will end and I can finally get my $3000+
turbo's back and put my car back together. Well early this winter after pretty
much forgetting my car exists in the back corner of the garage covered in 2+
years of dust I get a letter from Turbonetics. Here the letter is verbatim so
you can share in my enthusiasm for Turbonetics at this point.
*I didn't make any typo there btw. That was the carefully considered letter
exactly as they sent it to me after 2+ years of screwing me (smile)
Of course I left out about 20 phone calls to supposed managers like some John
Wang guy that would never return calls etc. The best part about this all. Errr
gee thanks for sending my check back after 10 months and never returning my
calls but YOU FORGOT TO RETURN MY $3000.00+ TURBO'S THAT YOU STILL HAVE!!!!!!
Not really sure you can call that project shelved but it's definitely removed a
great deal of wind from my sails sadly.
Kevin T. Wyum
P.S. Trev's death in the middle of all that didn't help things for that matter.
I don't know that we ever intended to market the set up seriously as we both
doubted there were enough people interested in putting out $5000+ for a high end
set up like that.
Date: 27 Mar 2001 18:32:29 -0800 HKS makes good cast and s.s. maifolds..standard T04 flange
________________
Date: Tue, 27 Mar 2001 20:03:34 -0500 South Florida Performance: 305-233-8520
________________
Date: Wed, 28 Mar 2001 16:19:21 -1000 (HST) I purchased an ss exhaust manifold from South Florida for my T-66
conversion. They swore there would be no clearance problems with this
set-up. Alas, they were quite wrong. I had to spend another $150 to have it
modded locally. Then I decided to ditch the whole thing because the ports
were just too dinky (stock sized for a non-ported car). HKS's excellent
super strong cast iron manifold with big, gnarly ports was a logical step
but alas it did not fit either. So, I ended up having the fellow who first
modded the South Florida manifold do an ss unit. Boy did he do a good job.
Thing was a work of art. Big ports, super thick walls, no fittment problems....
The moral of my story is know what you need. If your engine is ported on the
exhaust side, don't ruin the whole thing with a stock port manifold. Annnnd,
don't trust anyone who says that their manifold will fit your monster T-99
or whatever size you are thinking on getting. Turbo housing sizes vary, so
get the manifold manufactured locally if you can so they can actually check
the clearances.
__________________
Date: Fri, 30 Mar 2001 11:20:07 -1000 (HST) The fabricator's name is Keith Miyashiro, owner of Awsome Fabrications,
Custom Metal Works (808-351-9514).
I just got off the phone with him and he "reminded" me that neither the
manifold he did for me, nor the one made by South Florida Performance were
stainless steel (yes, I'm an idiot). He also said that the reason he and SFP
do not do ss is that it cracks too easily on rotaries in particular. He did
not say he would refuse to do ss, only that he would never be able to
confidently say that it would hold together very long.
Anyway, what he did for me was a steel manifold with 1/2 inch thickness
flange and 3/16 inch pipes (2 and 1/2 inch diameter ports for my particular
application which had very aggressive exhaust porting). He can do different
sized ports of course.
Price: $450 (I paid more, but he would love to do work for more members of
this list). This price is not dependent upon more than one order. If several
people make orders the price would drop to $425.
I did not get a price for ss but can, or anyone is of course welcome to just
call him.
Regardless of the fact that I'm too stuuupid to remember that mine wasn't
ss, I still stand by my opinions that he did a great job. Nice welds, very
solid construction, nice pipe bends. It was better looking than the SFP
manifold and I was completely happy.
If members want to try to set up a group buy, I can help if necessary. I
really like this guy personally and would love to get him some business.
_______________
Date: Fri, 30 Mar 2001 16:47:09 -0600 S.S. Manifolds are not the best for rotaries due to the heat. Theres a
slight chance of cracking at the welds with S.S. Cast Iron might weight more
but it can take the heat better
Picture of the turbo controls w/ silicone hose installed:
One word of warning to those replacing/tieing your vaccum hoses - there
was some discussion on this on the autocrossing mailing list a while ago. It seems
that tie-wrapping or even glueing the hoses is illegal in the stock category.
The rules read that if it is not permitted in writing in the rule book, it is not
allowed. And glueing the hoses is not allowed. Most everyone on that list admitted
that it is kind of dumb, but if someone was a really poor loser, they could protest you
for glueing the hoses on so they don't pop off. I suppose it also means that Loctite
is illegal. Sort of a dumb situation, but just something to be aware of. The
silicone hoses would definately be illegal, and a lot easier to detect. Some of
the stock hoses have clips on them to keep them secure, but not all. These would
be harder for someone to protest than the more obvious tiewraps. I don't know which
hoses came with the clips. Check the manual. --Steve
___________________
Date: Tue, 09 May 2000 10:59:13 PDT Having obtained several samples from various vendors I found that the 70
durometer hardness silicon tubing available at McMaster-Carr is better
suited for automotive use than the 50 durometer tubing most automotive
sources sell.
My high temperature testing of Viton, Neoprene and Silicon vacuum tubing is
completed and my new digital camera has arrived so I will be posting results
soon. The test involve exposing the tubing to motor oil maintained at 130
degC for 1,000 hours. The results don't look good for the silicone tubing.
At 500 hours the silicone tubing split lengthwise while the Neoprene tubing
became very hard. Even after 1,000 hours the Viton tubing looks as though it
just came out of the box.
___________________
Date: Sat, 3 Jan 1998 00:45:37 -0500 I don't know if anyone is interesed, but Cam at Pettit Racing told me *not*
to use the blue silicone hosing. He said that if there is any defect at
the end of the hose where you cut it, that it will begin to split quickly.
He told me to use Goodyear 5/32" vacuum hosing and tie wraps. He said the
5/32" hose will fit tighter over the fittings. Given his participation in
endurance racing etc..., I think that's what I'll do when it comes time.
___________________
Date: Sun, 5 Jul 1998 21:10:21 -0700 Mostly Mazda doesn't recommend silicon hose. Says that oil and gas
fumes will make a gooey mess of it. In the larger sizes you can find
lined silicon hose that doesn't have this problem but not in the small
(4mm) sizes of our control hoses. And oil spray/gas fumes are *gonna*
be going through those hoses.
I am not recommending anything here, just passing on what one expert
feels is good advice. Has anyone had degredation of their silicon hoses
due to oil/gas exposure?
____________________
While researching 2-3/4" silicone hose for my IC, I found out that there
is a special kind of silicone hose for environments where it could get
exposed to fuel or oil. It should be fluoro-silicone lined. So this does jibe
with the other posts above. The special kind of hose is more expensive
than the regular silicone hose too. --Steve
____________________
Date: Mon, 06 Mar 2000 11:10:07 PST Since it's getting close to vacuum hose replacement time for me and the
subject is under discussion... From what I can gather there are two schools
of thought on what type of vacuum hose material to use on the third gen. My
observation is that the majority of people choose silicone hose. With a
small minority going to high temperature fluorine rubber hose. Here is what
I see as the advantages and disadvantages (most of this info came from a
hose/tubing supply catalog I had lying around. So, if you have different
data, don't blame me):
So, silicone is cheaper, more readily available, has a slightly higher
service temperature, and comes in many cool colors. Its disadvantages are:
relative lack of kink, abrasion and cut resistance which is why most people
use tie-wraps or glue to secure the hose. Unfortunately, tie-wraps aren't
resistant to high temperatures.
Fluorine Rubber is more expensive, hard to find, and has a slightly lower
service temperature. Its advantages are kink, cut and abrasion resistance
which allows you to use spring steel hose clamps.
___________________
Date: Tue, 07 Mar 2000 09:18:00 PST >I am somewhat skeptical of silicone's resistance to gas and oil. It Max is right, here are the ratings from a "Chemical Resistance of Materials
Chart" that I use at work:
These tests are based on 48 hr exposures at 72 F. The table makes a big deal
about not using the data for higher temperatures or longer periods of time,
which would probably magnify the effects. The chart did not specify what
type of synthetic oil they used, so it may not be synthetic motor oil. I
threw sperm whale oil in there just because I know someone on the list is
thinking "I've used nothing but sperm whale oil in my rotary for over
200,000 miles with no ill effects, even though Mazda doesn't recommend it"
8).
___________________
I can answer the question of what sperm whale oil is used for - it used to
be (is) used in the differential. I used some back before I knew better. It
was considered to be better than petroleum-based oil. It stunk bad. Or is
that stunk good? :-) ___________________
(Editor's note: I am including the posts on the vacuum line below anyway.
If you choose not to use it, at least there is some good info on quantities
and lengths. --Steve)
____________________
Max Cooper has a MUST-READ site for this:
Hose & Ties.
___________________
I ordered my hose online from
Baker Precision.
___________________
Date: Wed, 15 Apr 1998 08:34:49 -0700 Get at least 20 feet of 4mm and 10 feet of 6mm. That should be plenty.
Don't for get the wire ties or safety wire to hold them in place. I use
wire ties on the "cool" side and safety wire on the "hot" side.
___________________
Date: Fri, 2 Jan 1998 18:31:59 EST (I got mine from) Elite Motorsports.
EM099: 3rd gen RX-7 hose replacement kit (blue) $39
The 'hose replacement' kit includes blue silicone hoses required & tie
wraps necessary to replace your worn out rubber vacuum hoses.
Red & yellow silicone hoses can be chosen for (EM099) at an additional
$5/kit ($44)
EM098 FD3S (3rd gen RX-7) hose replacement kit (yellow) $44 NOTE: Silicone hoses are available in 3 colors: blue, yellow & red.
Please specify color. Silicone hose joints are only available in blue.
Here's what you get in the kit:
__________________
Date: Tue, 9 Dec 1997 06:52:42 EST I also wondered about the possibility of the silicone tubing collapsing or
being pinched. The stock lines are preformed and much stiffer than the
silicone lines. The silicone lines can be collapsed very easily.
BTW. There was 14' of 4mm tubing and 9' of 6mm tubing along with 100 4" ties
wraps in the kit. For those of you that want to compare prices by buying it by
the foot.
_________________
From: Gene Guffey (geneguffey@hotmail.com) I found a good deal on vacuum hose at
http://www.hosetechniques.com/
They are having a sale on there RX-7 hose kit. Just thought I would pass
it along for anyone interested on the list.
Here's what ya get.
The sizes of hose are:
14 colors to pick from.
____________________
Date: Tue, 9 Dec 1997 08:18:44 -0500 I thought so too. To test them, I put a Mity-Vac to both
the 3mm and 6mm ID silicon hoses, applied 25" of vacuum, and
niether hose collapsed.
_________________
Date: Mon, 11 Jan 1999 09:14:36 -0600 > What is the prefered method for tying vacuum lines on a 3? Do you use Spend the money and get the mini spring clips that Mazda uses. They are
reusable, will not melt or brittle with age like ties, and will not cut
into the tubes like wire can.
__________________
Date: Tue, 02 Mar 1999 11:48:18 -0500 HOSE:
I don't know for sure, but I think PFS gets its hose from Baker
Precision (http://www.bakerprecision.com/) in Signal Hill, CA. They
have red, blue, and yellow for $1.20 a foot, specialty colors are more
expensive. I spoke to them and they said they sell thick-walled hose
which is less likely to kink than the more commonly available
thin-walled stuff. Judging by their location, I think they supply
MazdaTrix, and I think PFS uses the same supplier as MazdaTrix. Does
anyone have some of their hose to test for kink resistance?
CABLE TIES:
Tefzel is expensive. The only quote I got so far is about $60 for 100
pieces. Stainless Steel is about the same price. While it is not as
resistant to UV and chemicals, Heat Stabilized Nylon 4/6 is looking
good. It is rated for 275F operation and only costs about $2 for 100.
I just bought 10 bags of 100 from Web-Tronics
(http://www.web-tronics.com/). Web-Tronics' minimum shipping charge is
$7, and the price is cheaper ($1.88 vs. $2.39) if you buy in quantities
of 10 or more. That leaves me with about 8 extra bags (each job requires
~2 bags), so if you want some email me and I'll sell them to you for
cost + shipping. The part number is CV-120LW, and they are both weather
resistant (UV) and heat stabilized. I think they are black. Problem
solved.
___________________
From: Jason (continuum@gashead.com) The mail from Max Cooper on 02 Mar 1999 talks about the heat
stabilized nylon cable ties from Web-tronics. I contacted
them this week and they told me the information on their
website was incorrect and that they do not sell heat
stabilized wire ties. The part number listed in Max's email
is for weather resistant ones. They updated their webpage
to remove the incorrect information today or yesterday.
I found heat stabilized nylon ties at
http://www.nelcoproducts.com for $28.50 (1000 count). That
is the smallest package of them they carry. The ties are
black, 5" inches long, 3/16" wide, have a minimum bundle
size of 1/16", have 40 lbs. min. loop tensile, and are rated
at 221F. I didn't get the part number. They do not mind
taking orders from individuals and accept credit card
payment over the phone. Standard UPS ground shipping is
used and is an additional charge over that mentioned above.
They also carry Tefzel and Halar for the hard core people.
___________________
For the zip ties, make sure you get ones that are heat resistant. As we
all know it it pretty darned hot next to the engine.--Steve
___________________
Date: Fri, 10 Mar 2000 13:59:33 -0700 I've been following this zip-tie thread for awhile now, and thought
I'd look up the specs. from the manufacturer. I prefer Panduit as
they seem to have better quality stuff, though it's often not the
least expensive ;-) Max is right, nylon is rated as he said:
Looks to me like TEFZEL is the one (for Nuclear and Harsh
environments). Part number PLT1M-C76 (max. bundle dia. .87"). There
are seven different sizes available. HALAR is for "plenum
applications" and would be ok too, but may not be available in small
enough sizes (only one is listed - 1.88" max bundle). TEFZEL is a
teflon like plastic from DuPont. HALAR is too, but from Ausimont.
They also make stainless steel ones, but I'd be wary of them nicking
the silicone tubing, causing it to fail (though they say "no sharp
edges"). Part number for these is MLT1S-CP (1" max. bundle).
These should be available from your local electrical and electronics
distributors - I suspect you may have to "special order" though.
___________________
Date: Sat, 22 Apr 2000 10:36:47 -0400 I am sad to say Home Depot no longer carries the small (3/8") clamps for the
4mm ID vacuum hoses. They have a different one that is cheaply made.
Squeezing the ends together distorts it, resulting in poor fit over the
vacuum hose. The problem is in the squeeze tabs location being almost 180
degrees from each other, where as the old clamps there was only a 60 degree
seperation between the squeeze tabs.
KD Rotary has tried to contact the manufacturer only to find out they
discontinued the clamp. They are in negociations right now trying to
reintroduce them at a substantially lower cost too. In the mean time I had
to buy some from Mazda Comp. I suggest you save the following part number
for these 8mm clamps (for use with 4mm hoses).
___________________
For a diagram, plus instructions on how to do the job, see the
How-to page on this. --Steve
Date: Wed, 10 Dec 1997 08:09:40 PST > Also the pipe, located under front strut tower bar, connets the Not to take away from Kevin, but from the Pettit ((954) 735-0100)
on-line catalog (see the picture at
Race Parts,
halfway down the page):
0803-396 HI-FLOW POLISHED ALUMINUM TURBO PIPE KIT 499.95
This goes turbo-to-intercooler and intercooler-to-throttle-body.
Does the aluminum have a problem absorbing too much heat as it passes
over the engine, making the intercooler less effective?
_____________
Tri-Point offers a silicone replacement kit for the turbo pipe hoses.
(This is from Samco.) Spencer Hutchings took the following pictures of
them on his car:
Date: Mon, 9 Mar 1998 19:32:00 -0600 The replacement for the front half of the "Y" turbo outlet duct assembly (Mazda
calls it an air pipe) has three major changes:
The new crossover to IC duct/air pipe is larger inside where it goes under
the brace bar, and where it makes the 90 degree bend, has a larger and
smoother radius. It does not bolt down to the bracket between the alternator
and air pump like it use to. This piece is now made of aluminum!
The two pieces and gasket cost about $230. These changes are to improve the
flow rate from the turbos into the IC. They are meant to be used with the
stock or stock replacement ICs. Brad Barber who has an ASP IC only uses the
front half of the "Y" duct with the studs and flange cut off and then uses a
silicone hose to connect it to his IC.
Date: Mon, 9 Mar 1998 11:11:00 -0600 This Saturday, I installed the Efini turbo upgrade pieces on my 93 R1 which
also has a Greddy IC. I ordered the kit from Mazda Competition Parts. It has
three pieces:
You also need two common 12MM Mazda nuts, two lock washers, and 2 regular
washers Mazda calls these pieces by different names. The front half of the
"Y" duct installed perfectly and easily. Had two minor problems with the top
cross over duct. Even though it has an indented area so as to not hit the
alternator, it is about 1/4" off center. I had to grind down part of the
alternator to prevent it from rubbing too hard but it still touches a
little. This same duct which connects the "Y" outlet to the IC sits higher
than the stock plastic one. I had to raise the Greddy 90 degree connector
duct. In so doing the bottom blue silicone hose is just barely long enough
to be used. It measures 2 3/4" long and needs to be 4" long.
Haven't had a chance to see if it really makes any difference but will test
it soon.
_______________
Date: Wed, 07 Jun 2000 08:55:12 -0500 Yes, there is a difference in the castings. The Efini part has the boss and
pressed in pipe for the charge valve moved from the primary turbo pressure
path. On the original part the boss is obstructing the path. The flange is
nice, but I was more concerned with a free flowing intake path.
________________
Date: Thu, 03 Dec 1998 22:12:09 -0600 > 1. Do the new parts replace the Y-shaped piping leading from the compressor The "kit", which MazdaComp sells, includes these two pipes, a new air duct
leading to the airbox, a new air duct leading to the intercooler, and all
necessary gaskets. They also will sell the pipes seperately from the ducts for
about $200 (total), which is what I bought.
> 4. Is the connection between the Y-pipe and the next pipe leading to the Yes! The pipes have metal flanges that bolt together.
> 5. Who sells it?
Rotary Performance (www.rx7.com); MazdaComp
> 6 Anything else I need to know?
I think it's a much improved part over U.S. spec. It won't break or blow out
like the stock hoses/connection and it seems to be larger and thus more free
flowing. MazdaComp told me the "kit" was supposedly good for 10 to 15 h.p., with
most of that coming from improvements in the two pipes.
_______________
Date: Mon, 17 May 1999 08:49:08 -0500 At the time that I installed the Efini Y pipe on my car, a PFS PMC
was being used to controll boost and fuel. My boost went up just over 1 PSI
just by adding this mod. Both pipes allow better air flow because:
the lower pipe has the BOV port flush mounnted and not protuding into the
pipe as before,(2) the top pipe has a larger radius turn and is larger
internally in some places.
________________
Date: Mon, 19 Jul 1999 15:40:24 -0400 You can take one of two approaches with regard to the ASP Large for use in
conjunction with the (96+) Efini y-pipe. Both are labor intensive, and add
another $100-150 to the total price of the IC/y-pipe project.
Brad Barber (bradrx7@swbell.net) has a write up of his procedure on Rob
Robinette's website. Brad did in fact use the y-pipe, but not the crossover
pipe. Brad's configuration uses the originally spec'd design of the ASP and
thus has removed the air pump.
I have successfully installed a Spearco intercooler of the same core size as
the ASP large on my FD. The installation can be seen at
IC Kit. My requirements were
slightly different
than the ASP design because I intend to keep my air pump on for the visual
inspection and emissions compliance ;-). As such, I modified some existing
GReddy hardpipes that originally fit the stock intercooler. Not that much
work, but it allowed me to run the air pump and eventually use it with the
full Efini y-pipe setup. Images of this setup can be found at
Y Pipe. Pardon the crude
nature of the image layout. I did this just for you in about ten minutes. :-)
Since the completion of this project, I understand that Mostly Mazda now has
the rights to reproduce the ASP medium and large intercoolers. I also
understand that Brian Richards at Mostly Mazda will fab up a pipe to run the
Large IC in conjunction with the air pump. Though there are no images on
the www.mostlymazda.com website showing the optional air pump pipe (as of 18
August 99), I think all you have to do is ask.
_______________
Date: Sat, 3 Jun 2000 12:04:38 -0400 Y-pipe Results:
Only performance upgrade before last track session was the turbo y-pipe. The
unit, about $200 from mazda comp, had rough cast surfaces in and out, more
so than oem part. I ground all inside surfaces smooth (pia).
On the track, I have a bleed valve I usually trim to run closer to stock
fuel cut at the track, giving 1-2 more psi. I found that, with new y-pipe
boost was up fully w/o changing the valve at all. The boost increase showed
up mostly at high rpms, where drop off was less than in the past.
This mod results in less pressure drop, mabe 1+ psi, on the upper rpms, for
me at about 9 psi up there. For higher powered cars, the reduced pressure
drop would be more. This allows more efficient boost with less heat and
backpressure, but a big difference in perceived power if regulated to the
same boost as before. Also could make things a little leaner up there.
Install tips: Check Robinette's site for info. If you have air pump, remove
it. Be very careful unhooking the the larger vac hose to the rear of the oem
y-pipe. It is brittle and if broken, massive job to replace. Also, while
there, replace the small elbo hose for the bypass relief off the 2nd turbo,
as this hose gets hard and leaks. The final position of the cross tube is
about 1/3 inch higher than before, and some stock mt IC's, like my Greddy,
required a longer than standard connector hose. Got xtra long hose stock
from bakerprecision.com.
Date: Tue, 25 May 1999 18:07:11 -0700 Pop-off valve: A spring regulated valve designed to open at a specific
pressure, venting boost to atmosphere and preventing the engine from
receiving the full output of the turbos or an unsafe level of boost.
Blow-off valve: A vacuum actuated valve which vents boost to the
atmosphere in order to prevent compressor surge when the throttle body
is suddenly closed. Also allows quick spool-up after a shift, according to
some sources.
Charge relief valve: A valve which vents boost to atmosphere in order
to spool the second of a pair of sequential turbos quickly to speed prior to
being brought "on-line" by removing the restriction of the closed intake
system.
I'm sure you could call a pop-off valve a blow-off valve and be pretty
close, but they do serve different purposes. The sequential system on the RX-7
has one blow-off and one charge relief valve. The non-sequential conversion
converts the charge relief valve to blow-off duties.
________________
Date: Thu, 9 Jul 1998 10:21:09 -0700 A blow-off valve releases pressure from the system when vacuum is
present at the manifold, indicating that the throttle body butterflies
have closed or are closing. This prevents pressure from building up
between the turbos and the closed or partially closed throttle body
while the turbos are still producing significant output. This protects
the throttle body and the turbos and also (so some say) allows the
system to pressurize more quickly after gear shifts...
A pop-off valve vents when pressure has reached a certain level. It
is not controlled by vacuum (although the pop-off valve can be
repurposed as a blow-off valve after a non-sequential conversion)
but rather by pressure. Indy cars used this method (before the
elimination of turbocharging) to limit boost without a wastegate. In
our application, their use is intended to vent pressure created by the
second turbo while it is being spooled to bring it on-line. In Brooks'
case, he is using an additional valve to vent pressure from the system
between the turbos and the engine (including intercooler, piping,
throttle body, and intake manifold) when the pressure reaches a
specific level. This happens regardless of the position of the throttle
body, is not controlled by the presence of vacuum, and is intended to
prevent excess pressure in the event that spiking or creep (or wastegate
actuator, wastegate or boost controller failure) raises the boost level
above a safe amount for the engine to deal with.
If the pop-off valve spring is adjusted for 15 psi, the valve should open
and vent the system until pressure has dropped to a safe level. Obviously,
if you intend to run 15 psi, this is not where you're going to set the
pop-off, as it will tend to flutter, or fluctuate between opening and closing as
boost reaches and then drops below 15 psi. The valve that Brooks is using is
adjustable up to 18 psi, I believe.
So, the pop-off is used to control pressure created by the rear turbo in a
factory setup, but one can be added to vent excess pressure from the
system on any setup, non-sequential or factory, twin or single turbo. The
blow-off valve does not perform this safety feature, but only vents when
the throttle body is closing and vacuum is present in the manifold. It
therefore cannot help in an overboost situation until the driver steps out
of the throttle. As overboosting happens far too quickly for that to be a
practical solution, the pop-off is the ideal fail-safe for unsafe levels of
boost present in the system.
________________
Date: Mon, 16 Nov 1998 07:27:40 -0800 Bypass and Blow-off valves are designed to relieve turbo pressure in the
intake system when you take your foot off the gas. The two purposes for
this are to keep the throttle butterflies from "chattering" under the
pressure, and also to keep the column of compressed air in the system
from bogging down the turbo, which could delay spool up in the next gear
slightly.
A bypass valve releaves the pressure by venting it back into the intake
system before the turbo. A blow-off valve accomplishes the same thing
by venting the air into the atmosphere (which is what give you its
characteristic sound).
Third gens, and most high performance factory turbo cars, come stock
with bypass valves. Those who modify their cars sometimes think that
the stock set-up will not flow enough air to work if the boost is
elevated.
A couple of years ago, I posted a question about measured results with a
blow-off valve and got a single response that some group or other had
determined the benefit(not on RX-7s) between nothing and a blow-off
valve was only .1 second in the quarter mile. This makes me seriously
doubt that the stock bypass system on a 3rd gen would not be able to
handle all but the most radical modifications.
My car (GSL-SE with aftermarket turbo) has a bypass valve that was part
of the original kit. Bill Hahn--basically a drag racer--added a blow
off valve when he fabricated my intercooler ducting, saying that it
would only activate after full throttle running, while the bypass valve
would handle the rest. Corky Bell, who designed the turbo kit quipped
that he "didn't think much of those things" when asked about blow-off
valves.
So, Shiv and the others are essentially correct. If your car is
anywhere near stock (including the stock bypass valve) a blow-off valve
will have minimal, if any effect--other than to make a funny sound and
announce to the world that your car is modified.
If you are adding a turbo to a N/A engine, and if the kit doesn't
include a bypass valve, there is merit to adding a blow-off valve for
the performance increase and for keeping the throttle plates
comfortable. And, you get the funny sound thrown in. My wife says she
kind of likes the sound, but since I already have a bypass valve I would
probably remove the thing if it were not welded into the intake
plumbing.
________________
Date: Tue, 24 Feb 1998 21:19:26 -0600 Don't bother with any aftermarket blowoff valve if you are looking for
performance. The stock is more than adequate. If you simply have the
desire to hear a noise stick a valve cover breather filter in the
hose at the end of the stock hose. It'll make all kinds of noise.
The only other real reason for one is if you want a pretty little piece
to point at and show to your friends. There will be no significant
performance difference no matter how many adjectives the seller puts
in the name, a japanese tradition. People in the know will simply look
at it on your car and think, he has no clue.
_______________
Date: Tue, 24 Feb 1998 22:05:32 -0800 (PST) The car comes stock with the equiv of two blow off valves. They are made
of a very light composite (i.e.- they will react faster than one made from a
material with more mass), and IMO are superior to the aftermarket ones
avail.
Don't waste your money... there are many things on the third gen that could
definately be improved on. The blow off valves(s) are not one of them.
P.S.- A friend bought an R1 with a Greddy BOV on it. I removed it, and
compared its ID with one of the stock ones, and the Greddy one had a
noticably smaller ID which explains why it makes more noise, as noise
indicates restriction.
______________
From the Autospeed" Aftermarket Blow-off Valves Give Your Car More Power, Making It Go Heaps Faster...
Vehicle manufacturers fit blow-off valves to reduce
turbo flutter noise (when configured in a
closed-loop arrangement), and we've also heard suggestions
that they improve turbo life. Perhaps so. But today in the
aftermarket there are numerous dual-chamber, sequential,
double-whammy super-dooper BOVs that cost upward of
A$500 - which in reality, perform no better than most humble
OEM parts.
An aftermarket valve can perform better than OEM valves, but
only with those standard valves that leak under boost. If you've
replaced a BOV that used to seal perfectly, we guarantee you'll
be splitting hairs trying to measure any on-road gains. On the
other hand, one professional workshop we know suggested
one of their cars went harder WITHOUT its big shiny blow-off
valve...
If you really must have one, it is more than likely for the mystical
sound effects and so people can be "double whammy'd" when
you pop the hood. A standard BOV bought from a wrecker is
the most cost-effective approach.
______________
Date: Wed, 25 Feb 1998 08:04:00 -0600 Actually the best functioning BOV for the cost is probably one made by BOSCH
for the Saab turbo. It is a very plain (ugly) unit but only cost about $27.
I got this info from a Toyota Supra (yuck) page. They found it to be a
better quality item than their stock BOV. Read all about it at:
http://www.supras.com/bov.html.
______________
Date: Wed, 1 Jul 1998 11:24:12 -0400 I have a pop-off valve as well. Unfortunately, I recommended the pop-off to
Brooks (sorry). I have since shut it down, and so has Brooks I believe. The
problem with the valve is that the spring to release the excess boost is too
progressive. In other words, the valve will bleed the boost, but only enough
to try and keep under the limit. The valve can not open all the way because
it requires a higher boost to push it even more open (due to the
accomodation of potentially higher boost settings of other vehicle
applications). Bad! The turbos will over boost trying to provide the extra
boost which the wastegate is saying it is not receiving. What is required to
make it work is a very specific resistance spring which blows wide (not
partially) open to kill power and potential boost.
______________
Date: Mon, 21 Aug 2000 11:47:43 -0500 Next to the throttle body would be the best as it would keep the
air flow towards it. If you place it near the turbos, then you can get
backwards or static directional flow in the system past the turbos.
That is one of the faults of the stock system.
_________________
Now, if you STILL want one after that, read on... --Steve
Date: Wed, 25 Feb 1998 04:18:21 EST Here's my view on the blow off valves on today's market. They will help a
little bit, but not by much considering they cost from $250-330 a piece. Most
people get it to dress up the engine bay and they like the "pfffff" sound.
Here are your options if you definitely want one on your 7:
Personally, I'll pick the HKS one or the APEXi because of appearance..
But with the $300 I'd rather get something more useful such as fuel/boost
controller, mid/down pipe, etc.
Date: Mon, 20 Mar 2000 08:20:16 -0600 Many owners still get boost conversions wrong because
they confuse the different standards, or don't know
what unit of measurement their boost gauge uses. It
should be stated on the dial face.
My HKS boost gauge reads in Kg/Cm^2.
The following is rounded to one decimal point.
(ATM = atmosphere, the normal pressure at sea level of earth's
atmosphere)
A good site
for conversions.
>Why do people not just increase the boost like on The issue is that you can't just crank the boost up w/o other
modifications to keep the engine from blowing up, e.g.- new/upgraded
computer, bigger IC, possibly 3mm apex seals, etc. And if the engine
does not get enough fuel during periods of high boost, you will get
detonation and the apex seals will break, so you may need new
(higher flow) injectors. And maybe a better fuel pump if you
really mod the engine.
So it is not as simple as just cranking the boost up. But
I wish it were so... Read on for more info if you want to
increase boost and don't mind doing the required upgrades to
support it. --Steve
_________________
Date: Fri, 15 Oct 1999 01:18:48 -0400 The WG sol-valve controls boost by venting the
actuator, creating a pressure drop across the pill, with the reduced
pressure in the actuator allowing manifold boost above the basic actuator
setting of 8 psi (to initiate WG opening). This is a true 'bleed' or vent
control system.
STOCK CONTROL
The following 4 notes are the result of testing, not my less appreciated
theoretical type stuff. Some of that sneaks in later.
There are other interetsing traits, but these paint the picture pretty well.
My conclusion, based on the smooth, repeatable ramping of the duty cycle in
twin mode, is that a complex set of maps based on various inputs, are used
to passively control boost in an open loop mode. I like the low rpm boost
kick that generally results. The 'max boost cut-out vs rpm' table on Steve
Cirian's great site suggests the general boost profile that was desired by
Mazda.
AFTER MODS:
After heavy mods, I and others found boost (and spiking) was generally up.
This is due to increased vol-efficiency, and higher hp and exhaust flow at
the same old boost levels/conditions.
I said the WG flap cracks open at 8 psi. It is about 1/8 inch open (at the
edge away from the pivot) at 10 psi, and is opened a max of 1/2 inch at 15
psi. It is likely that max dump capacity occurs at much less than 1/2 inch
open, limited by port size. This data was taken off my OEM working system.
(Max open was about a 20 degree swing of the WG valve.)
Where before mods, 10 psi at a certain rpm/condition was a result of
sol-valve venting to create mabe 9 psi in the actuator, now that amount of
opening of the WG is not enough dumping of exhaust gas to keep boost
pressure from rising higher. So boost rises more to say 12 psi, and now the
actuator pressure is 10 and the wg is 1/8 inch open instead of 1/16 inch for
the stock condition, and boost sabilizes at the new higher pressure. Venting
duty cycle maps for the sol-valve are the same as before mods.
Larger orifices can recapture stock boost levels and control spikes. But w/o
an ECU upgrade, the increased volumetric efficiency with full
intake-exhaust-IC leans out the mixture, and ECU upgrades are needed, unless
O2 readings can confirm adequate mixture. Each car is a bit different in
this area.
PRECONTROL note:
Although some state primary boost is only controled by the precontrol WG, my
testing suggested it works in parallel with the main WG to control primary
boost. PLEASE, someone with a stock set-up, plug the line to the WG solenoid
valve, and see if primary boost drops (this would reassure me, and be proof
for doubters). Mine did, but I tested my car with heavy mods. This test is
safe.
_________________
Rob Robinette has an excellant page
on how the system works.
_________________
Date: Thu, 15 Jun 2000 16:32:23 -0400 Yes and no. First, oxygen is distributed evenly through the atmosphere.
There's less oxygen at altitude because there's less air, period, not
because less of the air is made of oxygen.
The total amount of pressure in the manifold is the same if you run an
extra 2-3PSI. But, you have to run a greater turbo pressure ratio to
generate that pressure. Your turbos have to blow more air in, and they
have less to work with. Consider:
Sea level, 10 PSI boost = 24.7 absolute manifold pressure / 14.7 ambient
pressure = 1.68 ratio
5500 feet, 12.7 PSI boost = 24.7 absolute manifold pressure / 12 ambient
pressure = 2.06 ratio.
Your turbos will have to work as hard producing 12.7 PSI of boost at high
altitude as they would producing 15.6 PSI of boost at sea level. That
means a hotter intake charge.
Secondly, octane is lower at high altitudes. You can get 92 octane in
Denver at some stations. But most gas stations at high altitude only have
91 and some don't even have that. This would be fine if it were 1975.
Of course they charge "premium" price for the same gas that is mid-grade
anywhere else in the country.
Combine bad gas with hotter intake... not good. Therefore, be careful
turning up the boost at high altitude.
_________________
See the Engine Management Computer page for more
info on things like the HKS, Greddy, etc. boost controllers. --Steve
_________________
Date: Wed, 24 May 2000 11:56:21 -0500 Some owners do not understand how boost is controlled
by the stock system. The following does not include
the minor affect caused by the pre-control system
that does bleed of exhaust pressure and thus affects
#1 turbo boost at about 4000rpm. Nor does it include
WG solenoid dual cyclic rates. This is a simple direct
and major operational explanation.
Boost pressure comes from the #1 turbo thru the air pill/jet
to one of the two WG actuator's connectors. This is where people
put the manual valve in place of the pill in order to control
the pressure build up rate. This is the pressure side of the
actuator. The other WG actuator connector connects to the WG
solenoid where pressure is bleed off. This is the atmosphere
side. If you bleed off no pressure, then minimum boost is built
which is equal to the actuator spring tension of about 7psi.
If you bleed off more or equal pressure than the pill supplies,
then you will have no boost control at all.
__________________
Date: Tue, 18 Nov 1997 17:40:10 -0600 The air bypass valve only opens when vacuum is applied to it. Notice that
the hose for actuation runs directly to the manifold. So, when you take
your foot off the gas and create vacuum in the system, it opens and vents
pressurized air to the atmosphere instead of letting it slam back into the
turbos.
>Also, can anyone tell me how the turbo control, wastegate and turbo Turbo control: located in the exhaust manifold between the rear rotor's
exhaust port and the rear turbo. Opens at 4500 allowing exhaust gases to
spin the secondary turbo and generate boost.
Wastegate: Located on the turbo housing, in the common exhaust area by the
precat port. Begins to open at 7psi, is fully open at 10psi.
Turbo Precontrol: Located on the turbo housing, with its own little port
being fed from the exhaust manifold. At 3000rpm, it opens and pre-spins
the secondary turbo. The charge relief valve is open at the same time, and
the charge control valve is closed, spitting any boost generated by the
secondary out the airbox. At 4500, the precontrol closes, and the charge
relief closes, and the charge control opens, allowing full secondary boost
to combine with the primary.
___________________
Date: Fri, 14 Nov 97 20:21:45 -0500 I installed an HKS pop-off valve to my car.....pictures and information
are on my website ....goto the whats
new section to find it quickly....
below is a text excerpt......
I installed an HKS pop-off valve on the exhaust side of the
intercooler. The valve has a spring loaded mechanism that
bleeds off excess boost above the set level. You can set the
valve too bleed boost between 12 and 18psi by adjusting the
screw. The valve reduces boost spiking by bleeding off
excess boost. The valve also protects the motor in case
something happens where excessive boost would be applied
to the motor. While the valve doesn't eliminate boost spiking
during the turbo transition, it does lower amount of spiking
and also acts a great protective measure for the car.
The HKS part #'s are:
The valve hardware came to a total of $65.43 from Stillen
Motorsports (714-540-5566). The welding was $40 from a
local shop.
________________
Date: Sat, 30 Aug 97 21:56:05 -0500 I have been struggling with different ways to control boost on my car,
and I think might have found the "perfect" way to control boost....for my
car anyways...
I have been changing the orifice in the wastegate line to control boost
for the last year or so. I have tried a manual bleed off valve in the
past. And I have been working with the profec lately.
The manual bleed off valve installed as most people do (wyum put my in)
makes alot of noise in the car, and I noticed alot of turbo lag on the
first turbo.
Changing the orifice is a very tedious and luck of the draw type of
procedure. I can either get 10, 14, or 16 pounds of boost....no in
between...i want 12.5 for street driving...
The (Greddy) Profec is working well, but im not convinced it controls boost as
well as the stock system.
So this is what i tried next.....i installed a bleed off valve in between
the turbo and wasteage line. This is the line that the orifice is in. I
removed the line that contains the orifice completely, and ran two lines
inside the car. One line goes to the turbo, the other line goes to the
top nipple of the wastegate. The two lines meet inside that car at the
bleed off valve.
With the valve all the way open, the car runs a rock solid 10 pounds of
boost on both turbos.
As i start opening the valve the boost increases slightly over the 6
turns the valve has. I can now very precisly dial in the exact boost
that i want. With the valve installed in this way, there is not much
noise from the valve, and there is absoultely no lag, its running like a
dream....
Has anyone else tried this yet??
___________
Date: Sun, 31 Aug 97 08:17:47 -0500 (included stuff snipped)
I am securing the hoses very well. There shouldn't be any pop-off's.
But, if there is a cut, or kink in the line, it would restrict the air
going to the wastegate, kind of acting like a smaller orifice, and
thereby increase boost. I think. Im not sure....
Any other ideas??
however, there is just as much of a chance of any of the other 100 lines
popping off, adding one more shouldnt be that much more of a problem...
i bought the valve from home depot.
the other line coming out of the wasteage...the bottom one, is still
connected....going to the soloniod...
_____________
Date: Wed, 06 May 1998 11:04:41 -0400 > Are you guys running your manual boost control valves on the wastegate line Ryan Schlagheck and I are running the dual Manual Boost Control that you
speak of. I've found it necessary with cars that have mods which remove the Cat
and/or downpipe and do not have an electronic boost controller. The wastegate
controller works great for the RPM's above 4500 when both turbos are online, but
boost below 4500 would consistently see 13 or higher while placing the car under
full throttle load.
Hence the Precontrol Valve. This allows us to control the
first turbo boost level easily and safely and have the over 4500 transition come
on to another desired level of boost. So far its working great.
I personally
have the Manual bleed valves set at 11.5 pounds below 4500RPM's a quick spike to
13lbs at the transition, and then a steady 12 lbs to redline.
Ryan, after just installing his new ECU, will probably be running 10, 12 spike,
10 lbs until we get his new Intercooler installed. The only flaw, which I have
also seen with some of the electronic controllers is the outside temp change.
Boost goes up a little when it gets colder. So we set them on cool nights, so in
the day we run about .5 lbs lower. It's better to be safe then sorry.
__________________
Date: Wed, 24 May 2000 07:46:50 -0500 No, do not disable it unless you only want about 7 psi of boost.
It is normally closed and thus would not bleed any pressure.
You don't want to bypass it either unless you are running non-seq.
The WG solenoid is cycled at two different rates which
affects boost. Before 4500rpm, it is cycled more which
bleeds off more pressure from the actuator which allows
more boost. This helps when running on only the #1 turbo.
After 4500rpm, the WG solenoid is cycled less thus reducing
boost.
__________________
Date: Tue, 23 Feb 1999 00:21:02 -0800 Following Gene Kan's Manual Boost Page, I installed the valves on my 93
Touring and have been "fiddling with the knobs" for the last few weeks. For
those who may be considering this modification, here is a table containing the
valve opening settings and the resultant boost patterns. The list of
(relevant) modifications to my FD is as follows: RSA Cat-Back, Downpipe,
Efini intake track. Average air temperature during testing was 55 degrees.
Average air humidity was 70 percent. Boost readings were taken via a
Blitz mechanical gauge (converted to PSI @ 14.5:1 bar).
As you can see, combination # 8 produces the smoothest powerband.
Unfortunately, as described by Gene Kan elsewhere and, as verified by my
"Dinamometro de nalga", on our FD's, a feeling of smooth power delivery means
that there is no real horsepower being produced... On the other hand,
combination # 1 seems to be the best all around setting that allows a
buffer zone for cold days/denser air. A close candidate is number # 2,
but that setting also seems to show a strong probability for boost creep
at the top end; again, that is if my "Dinamometro de nalga" serves me
correctly. YMMV.
This, of course is work in progress that will be updated as the other
modifications (ECU, IC & Intake) are installed.
Ed.'s note: Gene's is a modification of Brook's original strategy. --Steve
___________________
Date: Sun, 31 Aug 1997 06:58:29 -0400 (EDT) The idea Brooks was employed has been using by either HKS or Greddy a long
time ago. The Greddy one is called the t.v.v.c. and the HKS one is called
VBC (variable boost controller) What they do is to delay the signal sending
to the wastegate actuator, so the wastegate will open later which causes the
rise of the boost level I beleive both of them are sold around $250. The
t.v.v.c or the VBC is put between the turbo and the wastegate actuator
(between the orginal hose running from the turbo to the actuator) By turning
the knob on either the t.v.v.c or the VBC, the flow of the air will be more
restricted inside them.How they work is like this: For instance, the stock
wastegate will open at 7psi. When the t.v.v.c is installed, the boost inside
the hose connecting the turbo and the t.v.v.c will be 7 psi but because the
the flow of the air is restricted by the t.v.v.c. ,the boost inside the hose
connecting the t.v.v.c and the actuator will be lower which means the boost
is under 7 psi. If it's under 7 psi then the actuator will not open until 7
psi is realized so the boost level will keep increasing until the boost
between the t.v.v.c and the actuator is 7 psi.
_______________
Date: Fri, 12 Sep 1997 01:45:29 -0700 (PDT) Jim's car had repeatable boost creep in fourth gear. This was with an open
exhaust and non-sequential setup. Once we got a decent clutch in there,
most of the problrms went away, except the boost creep at partial throttle
positions in higher gears (bad I know, but you do it sometimes)
Anyway pulled the turbos, and took the primary turbo's exhaust housing to
my machinist. Looking at the waste-gate orfice with the circular flapper
valve open, you could see a ring where the flapper had been closing (wear
mark), This ring was offset a little, IE the waste-gate orfice was not
perfectly in the center of it. My instructions were to bore the hole
(using the milling machine) about 1/2 the difference in diameter between
the ring, and the waste-gate orfice, and to put its origin at the origin
of the ring, and not the waste-gate orfice's origin. (this requires a
mill, and not a drill press)
The bore was most of the way down to the back wall of the exhaust passage
(looking in through the waste-gate hole) and opened it up considerably.
Comparing it to one of the 93 housings I have sitting around it was a lot
larger, and perfectly round, unlike the 93 casting I have. Jim's 95
casting may have been more round than the 93...I didn't check, but don't
recall noticing that it was not round like the 93 one (very obvious)
I also used a die grinder on the area where the flapper valve opens toward
to give it more room, so it at least doesn't hit like it does stock. The
actuator won't let it go very far, but even a little will help.
Anyway we got a chance to test tonight (BTW not a single one of the
studs/nuts on the turbo, or downpipe that I had installed galled, unlike
Jim's factory studs which most of had galled and the nuts were perm.
attached to the studs). With boost set to .7 bar (assuming 1 bar is
14.7PSI then that is 10.29 PSI) the car was rather fast, and we easily hit
140 in my dad's neighborhood entrance (sorta long straight). I was
watching the boost on the EVC, and it was mostly at .79 bar (11.613 PSI),
and occasionally .81 bar (11.907 PSI). That run was from a dead stop, and
went to 7K rpm in each gear thru 4th, and into 5th for a short time (god
we were overdriving those low beams till the high got turned on :)
We also drove around and tested at non WOT throttle positions. Never once
did the boost creep, or even hint at it. As far as I am concerned the
amount I had it enlarged was enough to fix the problems. I would say you
could go as much as 75% the difference and not have any problems with it
sealing. Also note that the waste-gate orfice develops cracks around it
almost as often/fast as the secondary inlet cracks, but is not one that
most people will ever see since you must disassemble the housings, and
open the flapper valve to see it. This is why I believe you don't hear
about it cracking there. It is unknown at this time (or ever?) if
machining this out will increase or decrease the chance of cracks around
that orfice. My educated guess is that it will decrease it, because there
has been some stress releif, plus you are cutting away some of the stock
casting edges which may contain irregularities that could contribute to
the cracking?....
I feel I should post other options at this time: Running a less
restrictive pre-cat back exhaust (with a 3" downpipe) has been shown in
some cases to eliminate the boost creep problems. This is most likely due
to less backpressure making it more attractive for the exhaust gasses to
pass through the waste-gate orfice than the turbine. Its possibly related
to a 'sweet spot' type deal where the flow on the more restrictive exhaust
is open enough to cause the boost to rise quickly, but not open enough to
allow the waste-gate to fully control the boost.
The hollowed pre-cat is somewhat restrictive compared to a 3" downpipe,
yet yields decent amounts of power, and definately keeps the boost creep
at bay. Its also very quiet. You are losing some power, but this is a less
costly option than a 3" downpipe, and having to do the mods to the
wastegate.
Other option is to lose the stock turbos and go with something else with
larger external waste-gates :) BTW I am almost ready to ship the completed
manifold off to Kevin for testing. Just waiting on the machining of 2 of
the waste-gate tubes (of all things). And then will be able to have the
final welding done (right now 50% is welded, and the rest is tack welded
together)
(Note: all of the above assumes non-sequential, and a completly not stock
exhaust. IE 3" downpipe, 3" midpipe, and cat back type free flow muffler.)
Trev
P.S. looks like Jim is going to be driving down from Seattle WA to Willow
springs CA for Todd's Spet. 29th event with my dad and I. Someone asked me
about mods to Jim's car...I typed them, might as well send them to the
list as some are pertinent to the above:
- --------------------
> also, i've forgot what LaBreck's car is like (what's been done to it)
It was a 3 month old 95 PEP montego blue rx-7 with 4K miles on it. It now
has an R1 front spoiler, no A/C, no fog lights, no power steering, no air
pump, very few vacuum hoses, no main accelerated warm up system, no
secondary throttle control butterflies, non-sequential, opened up
waste-gate, tripoint downpipe, tripoint midpipe with a 12" borla XR-1
welded in the middle, PFS cat back, Mostly Mazda (MM16 ROM) fattest Fuel
curve, greddy water pump/alt pulleys, custom billet aluminum front
anti-sway bar mounts/radiator move kit, custom intake design, ASP race IC,
Hawker genesis battery, racing beat clutch, mazda comp pressure plate,
Redline MT90 in tranny, Redline MTL in diff, HKS EVC III, Pioneer CD
player, Racing beat front and rear anti-sway bars, Eibach Pro Kit Linear
springs, Koni adjustables, Toyo Proxy 17" tires, Konig Villian 17" rims,
Porterfield brake pads, Motul brake fluid, 3 wire O2 sensor, Efini badges,
and efini rear tailights, a Cosmo fuel pump, and a crane high 6, and 4
trailing spark plugs, the oil filler modification, greddy intake elbow,
and an SX adjustable rising rate fuel pressure regulator. Boost gauge,
loss of air bag components.
_________________
Date: Sun, 5 Apr 1998 22:08:00 -0500 You could use a manual bleeder valve for the precontrol just like some
use on the wastegate. From the description of your problem(13-11-10.5) I
would say that your pill/jet is too small for the precontrol. If you are
going to run only one boost pressure with your boost controller, it
probably is not worth the trouble to install a bleeder valve assembly for
it. Instead, just try a larger jet. This is how I optimized my jet.
Run two hoses(one from where each end of the orig hose connected) up to the
side of the fender where it can be reached easily. Connect a short 4" piece
of hose by two 90 degree connectors to the two hose ends. Have the pill inside the
4" hose. Set up your boost and observe the boost pattern. Then just remove
the 4" piece and replace the jet with the next size larger, and rerun your setup
and again observe the boost pattern. Repeat the process until the best
pattern is obtained. Then remove all of this extra plumbing, and install the
selected jet in the orig hose.
________________
Date: Mon, 10 Apr 2000 13:14:39 -0500 DESCRIPTION
The Hallman adjustable manual boost control system is a spring
loaded ball check valve with an inline air bleeder jet. It does
not allow air flow until the boost pressure overcomes the spring
pressure. The pressure is set with a knob and lock nut.
HISTORY
Since I'm running non-seq, I had bypassed the WG solenoid and
was using a .052" jet for bleed control and the infamous brass
water control valve for boost control. Use of the WG solenoid
was dropped because it bleeds off more before 4500 rpm than
afterwards. This was done to help build more boost on the #1
turbo before the #2 came on-line. With non-seq or a single turbo,
this would cause higher boost before 4500 then afterwards. This
might have certain applications, but I didn't want it. With the
WS solenoid working, my valve was opened about 1 1/4 turns for
12PSI boost. With the .052" jet, it was only opened 3/8 turns.
The jet method is better because it bleeds off less air and helps
boost to build quicker.
INSTALL
It was installed stock and tested two ways. First with the bleed
off nipple on the WG actuator capped. The supplied bleed off jet
is in the hose that goes from the valve to the WG actuator. The
second test was with the bleed off jet removed from the hose and
placed onto the original bleed off nipple on the WG actuator.
Both ways worked the same, poorly. The reason was due to the size
of the bleed off jet, about .078". The system was not bleeding any
boost until the valve opened, but then it dumped so much it was
worst than my original setup. I changed the jet to my .052" one,
and increased the spring pressure until my boost was about 12PSI.
Now thing were running better than with my original system.
Post setup removal of the valve and pressure testing showed that
it is not starting to pass boost until 7.5 PSI. The system is now
working as advertised. The only other minor difference, was in final
adjustment of the control knob. They said to start out with the knob
unscrewed 1/2" and slowly screw it in until desired boost is reached.
My end position is about 9/16" out. This is probably due to the fact
that the system was really designed for those DSM cars.
RESULTS
It works better than the manual constant flow valve in theory and use
but is it worth the $90. Only dyno results before and after would
really show. That will have to wait until the next dyno day here in
Houston.
________________
Upgrade Original Turbos
From: "Diep, Anh T" (DIEPAT@sce.com)
$101 each turbo rebuild kit,
$75 each turbo clipping the compressor wheels.
From: Max Cooper (m_cooper@csi.com)
PFS
=================================
* Clip exhaust wheels
* Garrett compressor wheel (T25?)
* ported housing / wastegate porting available
* 45 HP increase at the flywheel
* core required / cracks okay
* 2-3 week turn around
* $2795
Pettit Racing
============================================
OPTION 1:
* balanced and blueprinted
* ceramic coating
* ported compressor housing
* special process to lock compressor wheel nuts
* $650 core / extra charge if core has >8 mm cracks
* ready to ship
* $1695
OPTION 2:
* all the above stuff
* larger compressor wheels (not Garrett)
* 23% more flow
* $2195
Rotary Performance
=========================================
* bigger Garrett compressor wheels
* bigger Garrett shafts for greatly improved reliability at high boost
* trimmed exhaust wheels
* slightly more lag than stock
* pulls strong at high RPM
* 20%-25% better flow, less at lower boost levels
* 8-12 cars on the road with this, at least one running 18 psi for a
year
* Warranty (1 year?)
* 3-4 week turnaround at the present time
* $3100 + core
Turbo Performance Center
===========================================================
OPTION 1/2:
* Garrett T25 or T28 compressor wheels
* 30-35 more HP
* $1900
OPTION 3:
* IHI compressor wheels for significantly lower output temps
* slightly more lag than stock
* ~60 more HP
* 3 cars on the road with this
* $2400
COMMON STUFF:
* TPC has special jigs from Mazda factory reman project
* stock shafts (okay for moderate boost, <18 psi)
* 1 year warranty
* 4-5 day turnaround
* core required / there may be extra charge for really big cracks
From: Max Cooper (m_cooper@csi.com)
From: richardt@lava.net (Richard H Thomason)
Subject: Re: (rx7) [3] why not use upgraded sequential turbo instead of single turbo?
>How much more boost can be run with the greddy upgraded sequential
>turbo system? It would seem to me that if you can run up to 15-18psi of
>boost on this upgraded turbo system, that it would be more efficient than
>a big single turbo. IE: the sequential system will have less turbo lag.
>The only advantage I can see with a big single turbo is that your boost
>stays the same all the way through the power band, once you've achieved
>full boost, that is. Whereas the sequential system will still have that
>4500rpm drop?
Aftermarket Turbos
From: William T Wilson (fluffy@snurgle.org)
> reducing turbo lag, or increasing maximum psi that it can produce.
> the psi that it can produce?
> shaft? Can anyone tell me about them and how they can be upgraded,
From: marc.schaefer@am.bnpgroup.com
From: Max Cooper (max@maxcooper.com)
> reducing turbo lag, or increasing maximum psi that it can produce.
> psi that it can produce?
> Can anyone tell me about them and how they can be upgraded, either by
> replacing parts, or replacing the whole thing?
From: "Stephen Ziegler" (SMZ4883@yazaki-na.com)
From: Steven Kan (skan@ticnet.com)
From: Drizzt3117@aol.com
Subject: [mkiv] Single and Twin turbo kits, and their potential (long)
RPS:
TS04:
Most common housings for this turbo are 0.58 and 0.70, it makes
about 450 rwhp in the former and 500 rwhp in the latter, spools slightly
slower than stock, and can commonly be used on the stock fuel system.
This is a good turbo if you have an automatic, and can be daily driven.
T61:
Somewhat bigger than the TS04, this turbo can make 550-600 rwhp. It
requires an upgraded fuel system. This doesn't lag too much, a T61 car
lags a bit more than stock, but is streetable, if not particularly
responsive, could be used for road racing, not sure if I would recommend
this turbo for a daily driver.
T66:
Capable of making 600-675 rwhp, the T66 is a bigger turbo yet, this
is probably as big a turbo as I would recommend for the street, it makes
full boost right around 4250 rpm on most cars, a significant amount of
lag, but not horrendous... (full boost being 1.5-1.6 bar) This is a very
common turbo, and a nice setup for drag racing with some street driving.
T70:
Slightly bigger than the T66, the T70 is probably not a streetable
turbo. Lag is a couple hundred rpm more than the T66, power output ranges
from 650-750 rwhp... perhaps a bit more with headwork... This is a nice
turbo for drag racing.
T72+:
These turbos are only good for drag cars for the most part, lag is far
more than smaller turbos, power outputs are from 750-1000 rwhp.Twin turbo
kit: Using T25/28 ball bearing turbos, this kit will make slightly more
than 500 rwhp, while spooling faster than the TS04 0.70... very good
choice for a street car that needs more power than BPU.
HKS:
GT2540:
These twin turbos are used on the UPRD supra, and used in single form
on quite a few different cars. Nice turbos, not enormous lag, maybe slightly
more lag than their brethren the 2835s, but they spool a little faster
too... i'm told that car makes power in the 900 rwhp range on turbo alone,
but this could be just a rumor.
GT2835:
Probably the most common twin turbos used on supras, this kit is large,
and the turbos have a fair amount of lag, they make full boost in the 5000
rpm range, perhaps a bit higher. Very nice top end on this system, and
I've seen power output in the 700-800 rwhp range fairly consistently with
the right fuel support.
T04R:
A fairly large single turbo, this comes with a pretty big exhaust A/R
stock, 0.96... I would have thought it would be laggy, but my experience
with it shows otherwise... it spools a touch faster than a T66, but has a
bit more power output capability... it has made power in the 675-750 rwhp
range, and is becoming fairly popular because of this.
T51R:
This is HKS's biggest single turbo that is commonly sold, although it
isn't THAT much bigger than the T04R. Probably in between the T66 and T70
in size, the T04R makes full boost in the 5k range, and none has really
been able to realize its full power potential... i wouldn't be surprised
at seeing 800+ rwhp from a T51R under the right circumstances... very
strong turbo but i wouldn't use it on a street car personally.
Greddy:
T67:
The T67 isn't used on supras very often, its a TD07-25g turbo, more
commonly used on MR2s... its capable of right around 600 rwhp, and spools
similarly to a T66, so most people choose to go with either the T66 or
T61. Again, on the upper limit of streetability.
T78:
This is one of the more common turbos used on supras... it makes full
boost somewhat past 5000 rpm, but has the potential to make 750+ rwhp...
nice turbo, very good top end once it gets spooled... lots of drag cars
use it, and its fairly inexpensive now.
T88:
Somewhat bigger than the T78, the T88 has close to 1000 rwhp capability,
although i would imagine it makes full boost close to 6000 rpm, so a built
motor is almost a certainty with this turbo... not too expensive but its
not too usable on most supras so...
Blitz:
Single:
The Blitz single turbo uses a K27 turbo and is capable of right around
600-650 rwhp... spools somewhat faster than a T66, and the kit is well
made, but you need to modify it to work on the US spec supra, pain in the
ass to do.
Twins:
Supposedly capable of right around 700 rwhp with about as much lag as
the single, haven't really heard too much about it to corroborate this,
but I wouldn't doubt it... kinda of expensive, and this needs heavy
modification to work on a US spec supra.
Others:
TPC:
This turbo supposedly has 625-750 rwhp capability with faster spool up
than a T66... dunno enough about it to really say, but the dyno charts
seem to show full boost at right around 4500-5000 rpm, which isn't TOO bad
for a turbo with its power capabilities... not enough people use it to
really say.
Fastrax:
Fastrax makes all sorts of custom turbos... my experience with them is
that they make somewhat more power and spool somewhat faster than the
turbos they were built off of... fastrax has a lot of experience in the
drag racing scene, and they make high quality products. My Fastrax turbo
supposedly has 750-800 rwhp capability while spooling slightly faster than
a T66... it certainly spools faster than a T66 in my experience, we'll
have to see how much it puts down on the dyno.
Date: August 8, 2000
UPRD Sales/Tech
www.uprd.com
877-999-UPRD
From: "Eric Hsu" (dailo502@hotmail.com)
From: "Bernd Kluesener" (bklues@syskonnect.pp.se)
> I have literally been waiting for years for this group to become more
> interested in single T-O4 turbos on 3rd gens.
From: "Jason Baughman" (jbaughman@columbus.rr.com)
From: Aarroneous (aarroneous@pobox.com)
From: "Eric Hsu" (dailo502@hotmail.com)
From: "Jason Baughman" (jbaughman@columbus.rr.com)
From: "Steve Obrien" (poweraxel@peoplepc.com)
From: "Kevin T. Wyum" (aspi@winternet.com)
> > So has anyone tried parallel twins with a new exhaust manifold that
> > pipes each rotor to its own turbo? In other words, instead of one big
> > turbo, you run two small turbos completely in parallel. Does anyone
> > know if a different exhaust manifold would make parallel twin
> > performance more acceptable?
>
>Someone has, I want to say Trev D. did this a long time ago.
>I believe that Jim LaBreck is the custodian of that information.
>
>The manifold would definitely have to be designed and a set of turbos
>selected. I think the problem here, is that it would cost more to buy 2 smaller turbos
>than one medium one. I don't know how much better low-end would be, ala do you
>get instant boost at 3k/rpms like stock. Maximum boost doesn't offer any hardcore
>math to calculate the things I thought it did -- you'll need to get a hold of some SAE
>papers and maybe some other references to work out the math.
>
>The Supra guys do this, not sure how well it performs compared to a single turbo.
Dear Mr. Wyum:
Acount # phonenumber here
Thank you for sending in the check. Put as far as our accounts go your account
has been closed for quite sometime. So inclosed is your check.
Thank You,
Carolyn Thompson"
Turbo Manifold
From: Steve OBrien (poweraxel@peoplepc.com)
From: James T Fredericks (jfrederi@juno.com)
> I'm going to need to have a manifold made. I would like to have a
> Stainless steel one made. I understand there is a shop or person in
> Florida that does this type of stuff.
From: richardt@lava.net (Richard H Thomason)
From: richardt@lava.net (Richard H Thomason)
From: "Steve OBrien" (poweraxel@peoplepc.com)
Turbo Vacuum Hose Replacement
From: "Mike Putnam" (mike_putnam@hotmail.com)
>And McMaster-Carr also have small Viton tubing, which is
>probably the best alternative for the vacuum hose replacement job,
>though it costs more.
From: "Nicholas Riefner"
From: Dana Bourgeois
From: "Mike Putnam" (mike_putnam@hotmail.com)
Subject: (rx7) Re:[3] Vacuum Hose, Silicone vs. Fluorine
SILICONE TUBING
Operating temp -60 F to 460 F
Resistant to oil grease and solvents
Durometer Shore A hardness of 50
kink resistance - fair
abrasion and cut resistance - poor
Due to a lack of abrasion/cut resistance tie-wraps
or glue are recommended for securing.
(Unfortunately, the highest service temperature
for tie-wraps is below 200 F.
Widely available, comes in many colors
Cost (from tubing/hose supply catalog) $1/ft
FLUORINE RUBBER TUBING
(Sold under various trade names such as Viton, Fluran, etc.
I think that Pettit sells Goodyear's version of this tubing)
Operating temp -25 F to 400 F
Resistant to oil grease and solvents
Durometer Shore A hardness 60
kink resistance - good
abrasion and cut resistance - good
Spring clamps can be used for securing. ($0.20/clamp at Home Depot)
Comes only in black
Not available at most auto supply stores/catalogs
Cost (from tubing/hose supply catalog) $1.44/ft
From: "Mike Putnam" (mike_putnam@hotmail.com)
Subject: Re: (rx7) Re:[3] Vacuum Hose, Silicone vs. Fluorine
>seems to soften over time.
48 HOUR RATING SCALE
A- no effect
B- minor effect
C- moderate effect
D- severe effect
Chemical Flourine Rubber Silicone
Gasoline B C
Motor Oil B C
Synthetic Oil A B
Sperm Whale Oil A A
--Steve
Baker Precision
2865 Gundry Ave.
Signal Hill, CA 90806 USA
800 - 959 - 7757
562 - 427 - 2375
Fax 562 - 426 - 5294
From: Spencer Hutchings
From: EDRX7
EM097 FD3S (3rd gen RX-7) hose replacement kit (red) $44
EM091 Silicone hose (blue) 4mm $1.00/foot
EM092 Silicone hose (yellow) 4mm $1.25/foot
EM093 Silicone hose (red) 4mm $1.25/foot
EM094 Silicone hose (blue) 6mm $1.50/foot
EM095 Silicone hose (yellow) 6mm $1.75/foot
EM096 Silicone hose (red) 6mm $1.75/foot
Silicone hose joint 2 1/4" $4/inch
Silicone hose joint 2 1/2" $4.50/inch
Silicone hose joint 2 3/4" $5/inch
vacuum hose kit $45.00 total
includes: 14' 4mm hose blue
10' 6mm hose red
100 4" tie wraps
From: EDRX7
Date: Friday, March 03, 2000 5:33 AM
3.5mm ID, 40 feet: fits all the small vacuum lines under and over
the intake manifold and extra feet for
aftermarket boost controllers.
4.0mm ID, 15 feet: Windshield Washers.
6.0mm ID. 16 feet: Intake manifold and radiator overflow and there
is extra hose for aftermarket boost controllers.
8.0mm ID, 4 feet: other locations as necessary.
From: rotary@mediaone.net (Carlos Iglesias)
>I also wondered about the possibility of the silicone
>tubing collapsing or being pinched. The stock lines
>are preformed and much stiffer than the silicone lines.
>The silicone lines can be collapsed very easily.
From: "Westbrook, Chuck"
> plastic zip ties or actual wire like they use in racing to hold bolts in
> place?
From: Max Cooper
Date: 03/01/2002 03:31 PM
From: dbeale (dbeale@harddata.com)
Material Temp Range
Nylon -40 to +185 F
Flame retardant Nylon -40 to +203 F
TEFZEL -50 to +302 F
HALAR -50 to +284 F
Nylon 12 -40 to +176 F
Polyproylene -40 to +185 F
From: Wael El-Dasher (wael.el-dasher@efini.net)
Part number: 9928-30-800
size: 8mm (3/8") for use with 4mm (ID) vacuum hoses
price: $.65/ea. ($1.10/ea.from dealer!)
source: Mazda Comp
Turbo Pipe Kit
From: "Jeff Witzer"
> turbo and the intercooler piping. I always want an aftermarket one
> from long time ago, but there's no one making it.
"Y" Turbo Outlet Duct (Efini Y-pipe)
From: "Westbrook, Chuck"
From: "Westbrook, Chuck"
From: brad barber (bradrx7@bradbarber.com)
> I thought the reason people use the Efini Y-pipe is to eliminate the
> coupler? If you cut off the flange and welded a bead, then used a hose to
> connect it to the ASP pipe, wouldn't you be left with essentially the same
> setup as stock? Are there other differences with the Efini pipe other than
> the flange and "flat" metal tube?
From: GDK (gdolittle@postoffice.worldnet.att.net)
> outlets AND the pipe running from there to the intercooler?
> intercooler more reliable than the OEM rubber hose?
From: "Westbrook, Chuck E." (CWestbrook@tmh.tmc.edu)
From: "Ryan Schlagheck" (ryan.schlagheck@worldnet.att.net)
From: "kevin kelleher" (kellehkj@earthlink.net)
Blow-Off Valves
From: "Jim LaBreck" (jimlab@earthlink.net)
From: "Jim LaBreck (ECA)" (a-jimlab@microsoft.com)
From: "David H. Lane" (dlane@peabody.jhu.edu)
From: "Kevin T. Wyum" (aspi@winternet.com)
From: NetBlazer (netb@world.bc.ca)
article
on performance myths:
From: "Westbrook, Chuck" (CWestbrook@tmh.tmc.edu)
From: "Fritz McKellar" (sico@cyberus.ca)
From: "Westbrook, Chuck E." (CWestbrook@tmh.tmc.edu)
Subject: RE: (rx7) (all) BOV location
From: RudylRx7@aol.com
Boost Unit Conversion
From: "Westbrook, Chuck E." (CWestbrook@tmh.tmc.edu)
One ATM is equal to 14.7 PSI.
One Kg/Cm^2 is equal to 14.2 PSI.
One BAR is equal to 14.5 PSI.
Boost Control
>other turboed cars?
From: "kevin kelleher" (kellehkj@earthlink.net)
From: "Sandy Linthicum" (sandy-linthicum@nc.rr.com)
Subject: RE: (rx7) [3] Boost Levels at High Elevations
> As far as I understand, if I am at 5500 ft., I can run "higher
> boost" by 2.7 psi, and still have the same absolute boost level if
> compared to sea level. However, oxygen levels become lower with
> altitude. So is it really safe to run "more boost" at higher
>Depends on sensor used to measure pressure. If map sensor is a
>load cell type that is sealed with no outlet to ATM then 12psi
>measured in the manifold is 12psi at sea level or in space.
>Gas may be lower octane but 93 octane is still 93 regardless of
>altitute
>Intake may be cooler since inlet air would generally be colder.
>On the other hand, a lot more RPM is necessary at the turbo
>compressor due to thinner air.
From: "Westbrook, Chuck E." (CWestbrook@tmh.tmc.edu)
Subject: (rx7) [3] how boost is controlled
From: David Liberman (liberman@scott.net)
>pre-control all differ. My guess is that the wastegate controls exhaust
>volume to both turbos, the pre-control controls exhaust to the secondary
>turbo separately and I have no idea what the turbo control does but it
>appear to be separate from the wastegate.
From: Brooks Weisblat (brooks@miamisci.org)
HKS 1404-RA005 Adjustable pop-off valve
12-18 pounds
HKS 08108-09159 Flange
HKS 17678-001100 Gasket
From: Brooks Weisblat (brooks@miamisci.org)
From: Brooks Weisblat (brooks@miamisci.org)
From: Rippin (rippin@pottsville.infi.net)
> or the turbo precontrol line? My understanding (which I believe is correct)
> is that the precontrol is essentially the wastegate for the 1st turbo. Once
> max boost is reached on turbo 1, the precontrol begins opening, which bleeds
> exhaust pressure to the second turbo to pre-spool it. At this point, the
> wastegate control is doing little, if anything. Then, once the turbo
> control valve flips the big exhaust door open, exhaust gas is evenly divided
> to spin both turbos. At this point the wastegate control valve is used to
> bypass both turbos and bleed exhaust pressure.
>
> Thus, a manual valve in the precontrol line only affects boost levels when
> operating on the 1st turbo. If a valve is in the wastegate line, it will
> only control boost when operating in dual turbo mode. If my understanding
> is incorrect, please correct me. However, this is how Cam at Pettit
> explained it (or at least how I understood it), and it makes sense;
> especially when you consider that the precontrol & wastegate diaphragms and
> solenoids are essentially identical and have the exact same hose routing.
> They just connect to different control doors in the turbo assembly.
>
> So, to really control boost effectively you need to install separate manual
> valves in the precontrol & wastegate lines, correct? Is anyone on the list
> running this kind of setup, or has anyone tried it?
From: "Westbrook, Chuck E." (CWestbrook@tmh.tmc.edu)
> I have the "Home Depot" manual boost control. Ive been running this mod
> for about 2 months and it is effective. However, I have not disabled the
> control solenoid and have been told that others do. Can someone with this
> mod- or knowledge of it, let me know if I should disable the wastegate
> control solenoid.
From: "Emilio G. Littel" (emilio@littel.com)
ABBT = Average Boost Before Transition.
SBT = Spike Before Transition.
SAT = Spike After Transition.
ABAT = Average Boost After Transition.
Valve listings are number of turns from closed.
Combo# Pre-Control Valve Wastegate Valve ABBT SBT SAT ABAT
1 3.25 2.75 8.7 10.2 10.2 8.7
2 3.5 2.75 8.7 8.7 11.6 9.1
3 3.75 2.5 8.7 10.2 8.7 8.7
4 3.75 3 8.7 10.2 10.2 8.7
5 3.875 3.25 8.7 12.0 8.7 8.0
6 3.875 3.5 8.7 10.2 9.4 8.7
7 3.875 4 8.7 10.2 8.7 7.3
8 4 4 7.3 8.0 8.0 7.3
From: TAKESHI988@aol.com
(conncted by hose)
turbo-------------------------> input of t.v.v.c----->some mechanism which
restricted
air flow---------> output of t.v.v.c------------------------>wastegate
actuator
(connected by hose)
From: NetBlazer (netb@core.bisc.com)
Subject: (rx7) [3] stock waste-gate orfice
From: "Westbrook, Chuck" (CWestbrook@tmh.tmc.edu)
From: "Westbrook, Chuck E." (CWestbrook@tmh.tmc.edu)
Subject: (rx7) [3] Hallman Manual Boost Control Intall And Results