Intercoolers

Last updated: February 12, 1999

IC Theory

The Complete Guide to Intercooling
Part 1 - If you run a turbo or blown car, you need an intercooler for best performance.
By Julian Edgar
From
Autospeed Online

When a turbo or supercharger compresses air, the air is heated up. While this hot air can be fed straight into the intake of the engine (and often is), there are two disadvantages in taking this approach.

Firstly, warm air has less density than cool air - this means that it weighs less. It's important to know that it's the mass of air breathed by the engine that determines power, not the volume. So if the engine is being fed warm, high pressure air, the maximum power possible is significantly lower than if it is inhaling cold, high pressure air. The second problem with an engine breathing warm air is that the likelihood of detonation is increased. Detonation is a process of unstable combustion, where the flame front does not move progressively through the combustion chamber. Instead, the air/fuel mixture explodes into action. When this occurs, damage to the pistons, rings or head can very quickly happen.

If the temperature of the air can be reduced following the turbo or supercharger, the engine will have the potential to safely develop a higher power output. Intercoolers are used to cause this temperature drop.

Temperature Increase

There are a number of factors that affect the temperature increase that occurs when the air is compressed. Firstly, the higher the boost pressure, the greater will be the temperature increase. As a rule of thumb, if you are using a boost pressure level of more than about 0.5 Bar (~ 7 psi), an intercooler is generally a worthwhile investment.

Secondly, the lower the efficiency of the compressor, the higher the outlet air temp. However, it is difficult to accurately estimate the efficiency of the compressor and even if such a figure is available, it doesn't necessarily apply to all the different airflows that the compressor is capable of producing. In other words, there will be some combinations of airflow and boost pressure where the compressor is working at peak efficiency - and other areas where it isn't. While a well-matched compressor should be at peak efficiency most of the time, in some situations it will be working at less than optimum efficiency. This will change the outlet air temperature, usually for the worse.

Thirdly, the turbo- or supercharged car engine is not working in steady-state conditions. A typical forced induction road car might be on boost for only 5 per cent of the time, and even when it is on boost, it is perhaps for only 20 seconds at a stretch. Any decent forced induction road car will be travelling at well over 160 km/h if given 20 seconds of full boost from a standstill, meaning that longer periods of high boost occur only when hill-climbing, towing or driving at maximum speed. While all of the engine systems should be designed with the maximum full load capability in mind, in reality very few cars will ever experience this. This factor means that the heat-sink ability of the intake system must be considered.

If the inlet air temperature of the engine in cruise condition is 20C above ambient, then on a 25 day the inlet air temp will be 45C. After 30 minutes or so of running, all of the different components of the intake system will also have stabilised at around this temperature. If the engine then comes on boost and there is a sudden rise in the temp of the air being introduced to this system, the temperature of the turbo compressor cover (or blower housing), inlet duct, throttle body, plenum chamber, and inlet runners will all increase. These components increase in temp because they are removing heat from the intake air, limiting the magnitude of the initial rise in the actual intake air temperature. As a result, the infrequent short bursts of boost used in a typical road-driven forced-induction car often produce a lower initial intake air temperature than expected. This doesn't mean that intercooling is not worthwhile - it certainly is - but that the theory of the temperature increase doesn't always match reality.

Intercooler Efficiency

An intercooler will do two things - it will lower the temperature of the intake air and at the same time, cause a slight drop in boost pressure. The latter comes from the restriction to flow caused by the intercooler. Some restriction is unavoidable because the flow through an efficient intercooler core needs to be turbulent if a lot of the air is to come in contact with the heat exchanger surfaces. However, if the pressure drop is too high, power will suffer. A pressure drop of 1-2 psi can be considered acceptable if it is accompanied by good intercooler efficiency.

Intercooler efficiency is a measurement of how effective the intercooler is at reducing the inlet air temperature. If the intercooler reduces the temperature of the air exiting the compressor to ambient, the intercooler will be 100 per cent efficient. It will also be a bloody marvel, because no conventional intercooler can actually achieve this! Typical figures for a good intercooler are around 70 per cent.

Intercooler Types

Most intercoolers fall into two categories - air/air and air/water. There are also those special designs that cool the intake air to below ambient temperatures, using ice, the air-conditioning system or direct nitrous oxide sprays, but they will not be covered here.

Air/Air Intercoolers

Air/air intercoolers are the most common type, both in factory forced induction cars and aftermarket. They are technically simple, rugged and reliable. An air/air intercooler consists of a tube and fin radiator. The induction air passes through thin rectangular cross-section tubes that are stacked on top of the other. Often inside the tubes are fins that are designed to create turbulence and so improve heat exchange. Between the tubes are more fins, usually bent in a zig-zag formation. Invariably, air/air intercoolers are constructed from aluminium. The induction air flows through the many tubes. The air is then exposed to a very large surface area of conductive aluminium that absorbs and transfers the heat through the thickness of metal. Outside air - driven through the core by the forward motion of the car - takes this heat away, transferring it from the intake air to the atmosphere.

Described above is what is normally called the intercooler 'core' - the part of the intercooler that actually effects the heat transfer. However, there also needs to be an efficient way of carrying the intake air to each of the tiny tubes that pass through the core. End-tanks are used for this, being welded at each end of the core. While some cores are 'double-pass' (the inlet and outlet tanks are at one end separated by a divider, while at the other end the air does a U-turn), most cores are single-pass, with the inlet at one end of the core and the outlet at the other.

Good intercooler manufacturers have two specifications available - the pressure drop at a rated airflow (with the airflow often expressed as engine power), and the cooling effect (normally expressed as a temperature drop at that rated flow). However, many intercooler manufacturers have no data available on either of these factors! To some extent this doesn't matter greatly - the design of the intercooler is normally limited by factors other than heat transfer ability and pressure drop. Because an air/air intercooler uses ambient air as the cooling medium, an air/air intercooler cannot be too efficient - simply, the bigger the intercooler, the better. In fact, the maximum size of an air/air intercooler is normally dictated by the amount of space available at the front of the car and the size of your wallet, rather than any other factors!

It's easy to see how cost is a vital factor - those forced induction cars produced by major car companies as homologation specials (either for rallying or circuit racing) have quite huge intercoolers that dwarf the ones fitted by the same companies to their humdrum cars. Nissan used an air/air core no less than 60 x 30 x 6cm on their R32 Nissan Skyline GT-R and the Mitsubishi Lancer Evolution vehicles also use huge intercoolers. The "bigger is better" philosophy can be clearly seen at work in these cars.

Many factory-fitted intercoolers are undersized. Air/air cores no larger than a paperback book can be found in turbo cars with a nominal maximum output of 150kW. Cars equipped with this type of intercooler can be held at peak power for only a very short time before the increasing inlet air temperature causes the ECU to retard timing or decrease boost. A car fitted with this type of tiny factory intercooler is almost impossible to dyno test - the intake air temp rises so fast that rarely can more than one consecutive dyno run be made before the intake air temp is so high that the engine detonates... On the other hand, the aforesaid Skyline GT-R has a measured intake temp of 45?C on a 35?C day at 1 Bar boost and a sustained full-throttle 250 km/h!

Intercooler Mounting

When either increasing the size of a factory intercooler or installing a new one for a custom forced aspirated car, care needs to be given to the location that is chosen. The first point to consider is the amount of ambient heat that is present. An intercooler core absorbs heat just as well as it sheds it. This means that an underbonnet intercooler core can easily become an intake air pre-heater if care isn't taken with its location. Turbo cars run especially high underbonnet temps and so a bonnet vent designed for intercooler cooling while the car is under way can easily become a "chimney" ducting out hot air while the car is stationery - hot air that passes straight through the intercooler core. In fact, the behaviour of the intercooler while the vehicle is stopped is very important if you're in the habit of caning the car in traffic light Grands Prix!

By far the best location for an intercooler is in front of the engine radiator. The car manufacturer will have aerodynamically tested the vehicle to ensure that large volumes of air pass through the engine cooling radiator, and so an intercooler placed in front of that is sure to receive a great amount of cooling air. Note that the intercooler should be in front of any air conditioning condenser as well!

The air/air core should be ducted with the cold air if at all possible. Many people simply place the intercooler at the front of the car, hoping that the air being forced through the front grille will all pass through the intercooler. However, if there is an easier path for the air to take, that's the way it will go. Sheet metal guides can be used to channel the air coming in the grille through the intercooler, and foam rubber strips can be used to seal the escape routes that the air might otherwise take.

The plumbing leading to and from the intercooler should produce only a minimal pressure drop. Factory turbo cars often use intake ducts that smoothly increase in size from the diameter of the turbo compressor outlet (often only 50mm or so) to the inlet diameter of the throttle body (perhaps 80mm) and if this can be done, it's an approach which should be followed. Intercooler plumbing should have gentle curves and be as short as possible. Don't forget when you are planning the plumbing that the engine (and so also the blower or turbo!) moves around, while the body-mounted intercooler core does not. This means that some rubber or silicone hose connections must to be incorporated in the plumbing to absorb the movement.

The return duct from the intercooler should be insulated to avoid it picking up heat from within the engine bay. Lagging the pipe with fibreglass or ceramic fibre matting works effectively without being too bulky. The pipework can be finished off with a wrapping of aluminium adhesive tape of the type sometimes used to seal roofs. Also note when planning the intercooler pipework that the compressor cover of a turbo can be easily rotated to allow the outlet to come out at a different angle. This can reduce the number and tightness of the bends required.

Some people believe that if they fit a very big intercooler with large ducts, the volume of charge air within it will unduly slow throttle response. Their concern is unjustified however - throttle response problems (for example, turbo lag) are largely the result of other factors within the forced induction system, not the volume of air within it.

Sourcing the Core

There are a number of ways of getting together a very good air/air intercooler. Those companies specialising in the production of intercoolers (Spearco in the US is one of the largest) have a huge variety of cores and end-tanks available. However, as an aluminium item of fairly intricate construction, they are not cheap. For a really big air/air intercooler complete with end tanks, expect to pay about as much as you would for a turbo.

An alternative in Australia are the Japanese importing wreckers. While few factory turbo cars have really large intercoolers (and even less factory supercharged cars have them!), there are at least a couple of large ones available. As mentioned previously, the Nissan Skyline GT-R and Mitsubishi Evolution model Lancers all have very good intercoolers. The Nissan Pulsar GTiR also has a large intercooler (pictured), while the Mazda RX7 single turbo Series 4 has an engine-mounted intercooler that has a good flow, despite its appearance. Welding two of the RX7 intercoolers in series has also been shown to work very well.

You can also produce your own intercooler by modifying heat exchanger cores designed for other duties. However, having personally done so, I can advise that it is a great deal of work! One source of efficient heat exchangers are old airconditioners. Domestic and industrial refrigerative airconditioners use copper tube and aluminium fin heat exchangers for both their evaporators and condensers. When the airconditioner is discarded (perhaps because of a faulty compressor) these components are sold off at scrap value - less than the price of a few spark plugs! If you are patient and handy, you can cut off each end of the core and make plates that fit over the multiple copper tubes. Making end tanks that attach to these baseplates is then straightforward. The resulting copper-cored air/air intercooler is efficient and very, very cheap.

Another alternative it is to visit truck wreckers. Diesel turbo truck intercoolers are absolutely huge. They can also often be picked up very cheaply from insurance repair jobs, where the core has been twisted slightly, or one end tank damaged perhaps. If you chose with an eye to modification, the core will be able to be shortened without new end tanks being required - which substantially reduces the amount of work! This way you need only make new blanking plates for the ends of the shortened tanks. However, be aware that reducing the number of tubes of a truck intercooler in this manner can also reduce its flow by an unacceptable amount.

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Autospeed Online also has an article on air/water ICs.

List of Vendors

Date: Mon, 28 Jul 1997 23:46:09 -0700
From: elitemotorsports@juno.com

FYI, the Nuformz intercooler (front mount) is simply an APex'i, Japan IC core/kit.

GReddy/Trust IC kit: mounts to stock IC location, comes with 2 pipes/joints leading from top and bottom of IC, 4 blue silicon hoses and 8 clamps. Mates to stock plastic pipes perfectly. 3 row IC fins. Great fit and finish. More than sufficient for you circuit (road) racers out there (ditto me).

(GReddy/Trust also offers a front mount but it's only for the single turbo upgrade use.)

HKS IC: Front mount is way too $$$ expensive at over $2000.

A'Pex'i IC core/kit: Not bad, 3 row IC core, close to $2000 also.

PFS IC: nice red paint, other than that, the core is not much bigger than the stock IC. The end tanks take up more space than the IC fins/core.

ASP IC: Nice looking units (on Kevin's car), his performance proves it works. Fit/finish looks good too. Spearco core (?)

Blitz IC: WAY over prices ie all their products. Low to nil market presence (in the US, at least).

IC Comparo

From: Rick Zehr (rzehr@pacbell.net)
Date: 03/21/2002 10:38 PM

For those who are considering one of the less extreme intercooler upgrades, here is some info won from personal experience and a lot of research on the topic.

I hope this helps save others some time. I bought one used IC and was ready to install it, until it became evident how much work it would require on other aspects of the car to accomodate the IC. I now have a Blitz stock mount (which really is), and found it to be a much greater performance improvement than a RB cat-back (long since sold), with much less noise.

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Date: Fri, 20 Mar 1998 10:41:05 -0500
From: Rippin (rippin@pottsville.infi.net)

For all you fellow members looking for intercoolers out there, here are some Specs on the core sizes of each:

Intercooler		Thickness	Width		Height		Volume
________________________________________________________________________________
Stock IC		2.5 		11.5		4.5		129.375
ASP medium   		3.5		12.55		11.55		507
ASP race		3.5		12.55		17		746.7
Greddy Stock location	4.0		12.5		7.5		375
Greddy Front Mount	4.0		16.0		10.5		672
PFS			3.5		10.4		10.5		382.2
Pettit Cool charge2	3.5		10.5		10.0		367.5

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Date: Tue, 10 Jun 1997 19:45:05 -0500
From: "Kevin T. Wyum" (aspi@winternet.com)

Okay, as promised I got the actual numbers and performance data for a few intercoolers. Although it was claimed that we would never know a real answer on the issue of IC's here it is. As the data shows below it is very clearly the case that a bigger IC core will increase performance. I hope this will now put the debate to an end and that the detractors will realize the error of their theories.

I'm not pushing any particular product, I'll let Brian at Mostly Mazda or Cam at Pettit do that. These happen to be examples that I have data on for obvious reasons and another example to prove the point.

These tests were done by Spearco who maanufactures the core itself for all of these intercoolers, the data is provided by Spearco. There is no potential bias involved.

Based on John Duff's reply on one of the posts I feel that I should define what pressure drop is. If you need further explanation of it just ask. Pressure drop is measuring the difference in pressure across the IC with no airflow through the outside. It tells you how restrictive a core is. If the core has a small number of passages for air to travel through it will be more restrictive. In a practical sense what it tells you is that the turbos will have to produce x * more psi than what you see at the manifold because it has to overcome the restriction at the IC. For example if a core has a pressure drop of 1 psi that means the turbos will put out 16 psi in order to see 15 at the manifold. Of course the higher the number the harder the turbos have to work and the hotter the charge temp will be on that side of the IC.

* x = pressure drop across the core.

PFS IC

Core 3.5" x 10.4" x 10.5" CID of core 382.2

CFM of air flowed at 1.5 psi of pressure drop 410

Pressure drop at 10 psi and 6000 RPM 1.25 psi

Efficiency of heat transfer at 5mph air speed through core. 43%

Efficiency of heat transfer at 20mph air speed through core. 71%


ASP Medium IC

Core 3.5" x 12.55" x 11.55" CID of core 507.3

CFM of air flowed at 1.5 psi of pressure drop 620

Pressure drop at 10 psi and 6000 RPM .6 psi

Efficiency of heat transfer at 5mph air speed through core. 56%

Efficiency of heat transfer at 20mph air speed through core. 86%


ASP Race IC

Core 3.5" x 12.55" x 17" CID of core 746.7

CFM of air flowed at 1.5 psi of pressure drop 760

Pressure drop at 10 psi and 6000 RPM .35 psi

Efficiency of heat transfer at 5mph air speed through core. 76%

Efficiency of heat transfer at 20mph air speed through core. 88%


Small core unknown what application it is used in. Example of small core

Core 3.5" x 6.6" x 11.55" CID of core 266.8

CFM of air flowed at 1.5 psi of pressure drop 320

Pressure drop at 10 psi and 6000 RPM 2.2 psi

Efficiency of heat transfer at 5mph air speed through core. 38%

Efficiency of heat transfer at 20mph air speed through core. 70%

(This is actually a dense fin design core and pretty good for its size)

So as you can clearly see by the data a bigger core will produce temps closer to ambient at all speed ranges and do so with less work on the part of the turbos. So additionaly you could expect more life out of your turbos with a less restrictive core. Please also note a large core will actually reduce the temperatures more than a small one at even 4 times slower air speeds. So the arguement that the opening over the radiator top is only so big is an invalid point.

_________________

From: kevin kelleher [SMTP:kellehkj@earthlink.net]
Sent: Friday, January 21, 2000 10:58 PM

Based on Jeff Hoskinson's recent post on the SR IC, I finished up this comparison in progress........

If you mostly putt around like a new vette owner, the stock set-up is fine. If you occasionally get on it for short blasts, the RB duct will help power.

But, if you track the car, or otherwise drive hard with sustained boost, the stock IC should be replaced with a larger unit with a dedicated air supply. Check Rob Robinette's site for more on this. At stock boost, and separated intake air, I still measured over 190F charge temp at the track with stock IC. Many trackers still use the stock unit, with minimal mods. For them, a small IC upgrade (SR) may now make sense.......

 
   VOL = gross core volume
   FA  = gross charge flow area (actual flow area around 40% of this, less for
         stock and Greddy tube type cores)
   CA  = gross cooling surface area

***The 'SR' W and L dimensions are approximate, could be 12 x 6.4

In general, a large FA reduces pressure drop, and cooling efficiency is mostly improved with large VOL size and 'L' dimension.

Currently available small IC's (all use stock air duct, and the M2 and SR use stock hoses.....not sure on the blitz):

 
 TYPE---[ W   L   T ]---VOL--[FA, CA]--$$$
 
 STOCK--[ 11.5" 4.5" 2.5" ]--129---[29, 52]--xxxx
 M2/MC--[ 11.5" 4.5" 3.0" ]--155---[35, 52]--$540
 BLITZ---[ 11.0" 5.5" 4.0" ]--242---[44, 61]--$950
 SRMS--[ 11.5" 6.7" 3.5" ]--269---[40, 77]--$725 ***
 
 Popular Mid Sizes:
 
 GRED--[ 12.5" 7.5" 4.0" ]--375---[50, 94]--$1200 no duct
 PFS---[ 10.4" 10.5" 3.5" ]--382---[36, 109]--$1350?
 
 
 The BIG Guy:
 
 M2(med)--[ 12.6" 11.5" 3.5" ]--504--[44, 145]--$1500+?

The M2 (Mazda comp?) small proved to be no better than stock on the SCC test, and above number explain why. Who knows why Brian carries it.

The Blitz is a work of art, but not a great value. With a 4 inch thick core, it should have very low pressure drop. It also may work OK with a slightly mod'd stock duct.

The SR unit is the best bang for the buck, among the smalls. It should have a little less pressure drop than the PFS. It's a nice bridge between stock and mid units. It is also the longest of the smalls, which improves the efficiency. It will require some careful surgery to the stock duct for proper cooling. But if you are tempted by the SR $300 pipe set for it, the total is less of a bargin at $1000+. Hope SR does some tests for pressure drop and charge temp, at a road course, vs the stock unit.

But a better buy would be a used mid sized unit, like Greddy, PFS, and the Pettit-2 unit, if available. To get the most from the Greddy, a Pettit (or PFS) duct must be modified for it. Those trackers at stock boost, with nearly all intake and exhaust mods(but no midpipe), should advance to a least the mid sized IC.

As always, you should check fuel mixture with any mod. Fuel will likely be an issue with the larger M2 IC's.

Greddy

Vendor alert - Peter (elitemotorsports@juno.com) and Trey Cobb (trey@rx-7.com) are vendors - they seem like good guys, but I just wanted to make sure when people know the info is from a vendor. --Steve

Date: Thu, 23 Oct 1997 23:42:04 -0700
From: elitemotorsports@juno.com

A news flash: GReddy has come out with their FRONT MOUNT IC kit version for the FD3S (3rd gen RX-7). We received word about this earlier in the week and the specs on the intercooler are: 400mm x 265mm x 85mm. List price on this kit is $1580, but we offer a better price for fellow FD owners. Please visit our web page to find out more.

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Date: Mon, 10 Nov 1997 14:50:21 -0800
From: Trey Cobb

> very interested to test the two to see how they compare. Anyone
>running on the street with a front mount? Curious to see if there
>are problems with over heating since it preheats the air to the
>radiator. Also any core punctures from rocks?

As far as sizes go, the GReddy Front Mounted IC is 16" long, 10.5" Tall, and 4" thick (not including end tanks). I have some pictures of one installed on a '94 Touring but he supposedly got an early kit and the other shop modified some of the piping to make it work with the stock turbos. The kits come in two different piping configurations, stock twin turbos or GReddy single turbo. The core and brackets are the same.

As far as overheating, it's the same song and dance. The radiator is tilted up a little for more direct air flow (even though it's through the IC) but even in the stock configuration, the radiator relies heavily on the fans for air flow. Air flow through the IC should also be decent since it doesn't use a typical Spearco square tube core. The GReddy uses a round tube core design with better inner fins for more cooling and flow. The IC does sit right up in the front of the stock air dam so rock punctures are possible. You might want to install some racing wire mesh before the IC to keep rocks, small animals and children out. ;-)

I'll try and put pics of the new IC installed up on the web site tonight. Right now we have the kits for the single turbo in stock and we are taking orders for the stock turbo kits. (Unfortunately there is a waiting list for the stock turbo kits). This kit will take a few hours to install and if you want a unit immediately, you can use the single turbo kit and just modify some pipes.

The list price on the unit is $1580, complete for either stock turbos or GReddy single turbo.

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The following note from Brooks refers to the older Greddy IC. --Steve

Date: Tue, 29 Jul 97 09:09:07 -0500
From: Brooks Weisblat

I have seen the Greddy Kits. The one I saw didn't even come with a duct to route the air to the IC! What a waste with the IC just sitting there.

Also be warned the Greddy is pretty small and looks no bigger than the PFS unit.

_________________

Date: Sat, 4 Apr 1998 23:10:22 -0800
From: PAUL_FAUCHER@hp-sandiego-om2.om.hp.com

I had to trim my stock duct and fab some aluminum extensions to fully utilize the Greddy intercooler. It was quite easy.

_________________

Date: Sun, 5 Apr 1998 18:07:00 -0500
From: "Westbrook, Chuck"

Even with this mismatch, the Greddy is still a lot better than stock! It's over twice as big as the stock one.

Mostly Mazda (formerly ASP)

Kevin Wyum, owner of ASP, has sold the rights to manufacture the ASP IC to Mostly Mazda. --Steve

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Date: Thu, 26 Nov 1998 04:38:21 -0500
From: Max Cooper

Based on what I have heard, read, seen, etc...

The ASP ICs are perhaps the best ICs you can get. You have to get the GReddy piping kit elbow (I think Pettit and ASP might be making their own soon -- so check with them first), but the IC kit comes with the rest of the pipes. The result is hard pipes from the y-pipe to the throttle body that yield a short, reliable, free-flowing system. ASP is also known for including the best ducts in their kits. The ICs themselves have been carefully selected to give the best combination of pressure drop and thermal efficiency. Silicone pipe connector hoses and constant-torque clamps round out the package.

You can get the Medium IC and avoid having to move the battery or remove the air pump. Both kits require an aftermarket intake system (available from N-Tech, Pettit, Mostly Mazda, etc.), however.

The Race or Large IC may not require that the battery be moved, as a soon-to-be-available small battery kit (from N-Tech -- http://home.att.net/~racin/) will yield the proper clearance. Alternatively, a battery relocation kit is available from Pettit Racing (http://www.pettitracing.com/). It is rumored that you can also keep your air pump with the Race IC with a small modification (bend) to the pipe that feeds the IC inlet. The Race IC offers maximum performance, and the small battery kit makes it convenient -- UNBEATABLE!

Last I checked, the Race and Medium ICs were the same price -- $1500. Plus the required piping elbow, add about $200 (really, it is a little less). The small battery kit should be about $175 (I think?), if you want the Race IC and want to keep the battery up front. For the sake of cost comparison, you would need an IC ($1200-$1400) and piping kit ($300-$400) for a total of $1500-$1800, and that still does not replace all the pipes, nor will the system be as efficient. The ASP comes in at about the same price, but offers better performance.

ASP ICs are available from Mostly Mazda or from ASP directly.

I ordered the ASP Medium IC after doing a lot of comparisons (and before I knew about the small battery kit!), and I really think that ASP offers the best solution. I am not affiliated with ASP in any way, I am just relaying the information I uncovered when I was shopping, and ASP came out head and shoulders above the competition. As always, YMMV.

I should mention that I did not look too closely at front-mount IC kits because their drawbacks (installation difficulty, IC core vulnerability, impact on radiator cooling efficiency, increased plumbing volume, cost) did not seem to outweigh their advantages (more space for a big core, direct airflow).

______________

The Greddy elbow is the one most people are using. You do not need the injector bosses on it, unless you are going to add extra injectors at some point. However, most people do not add these - they put bigger injectors in the stock locations (secondaries in the primary location is an easy swap). --Steve

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Dana responds regarding how to keep the airpump with the ASP Race IC. --Steve

From: Dana Bourgeois
Date: April 26, 1999

MM had a custom bent intake pipe made for me out of the stock straight pipe. I'd bet that M2 will start supplying either pipe as required although the bent one may cost more. If not, start asking Brian and Mark about it. Making the bent pipe is pretty easy compared to making some of the other parts M2 sells. It could just be a case of enough demand.

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Date: Mon, 28 Jul 1997 23:16:24 -0500 (CDT)
From: Brad Cook

I love the ASP medium sized IC, but it DOES NOT replace the stock IC perfectly. You need a different intake system and it will fit perfectly...no hood rubbing whatsoever. I would not consider buying an IC that works with the stock intake as it surely would be too small and not worth the expenditure. The medium ASP IC will, however, fit with the battery and air pump underhood. If you use the big air duct supplied your charge temp will be drastically reduced. I cant believe how cool the right side of that IC is....even on hot days. When I only had the upper duct installed it wasn't nearly as cool. If I had to do it again I would get the same one. I can't really say that about all my other mods so that ought to tell you how happy I am with Kevin's unit.

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Date: Mon, 29 Sep 1997 02:20:50 -0500
From: Kevin Tan

2 or 3x the size of the stock intercooler. ASP offers two: medium and large. 95% perfect design for the large, and 100% perfect design for medium. The 5% fault in the large size is that the custom made air duct covers about 98% of the intercooler, leaving a little tiny gap at the end of the intercooler. but if you consider the size of the intercooler, it really doesn't make that much of a difference.

Review on Large intercooler (only cos I have one!!):

Requires a bit of work. Battery location required, must be used with an aftermarket intake. won't fit w/stock airbox. Cool to the touch after hard runs!! which is actually pretty amazing!! Fan can be turned on to draw additional cool air to the intercooler anytime.

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Date: Tue, 4 Nov 1997 16:09:04 -0600
From: "Kevin T. Wyum"

Actually Brian at Mostly Mazda stumbled on this, not me since I don't do many of the medium IC's in person.

I've posted about the medium one before as far as performance specs which it outperforms any of the others on the market except the big one, not sure about the front mount though. The core cubic dim. Is about 525 CID as opposed to the large of 760 and stock of about 180. If anyone has that post please put it up. Anyway the scoop is that the medium IC not only fits with the Battery in the stock location but also will fit with the Air Pump in place with no problem. It also fits with all but one after market intake system and stock. In the past I have misstated that I didn't think it would fit with the air pump either, but I was wrong it does. That's all. Just thought people might want to know.

____________________

Someone mentioned that they thought they could have a custom mount IC fabricated for way less than what ASP is charging. Here is Kevin's rebuttal. Lots of good info on how the ASP ICs are designed and constructed. --Steve

Date: Tue, 13 Jan 1998 04:22:56 -0600
From: "Kevin T. Wyum"

PRICE:

I'm glad you have dealt with Spearco. They are good people and do very nice work. Feel free to look up a core of the same size. Also note the ASP IC uses 2 3/4 inch output and input tubes. Why do I mention this? None of the cheaper cast aluminum endtanks are large enough to fit more than a 2 1/2 inch tube so I have to have hand made ones. This means that the end tanks are hand cut aluminum and then individually tig welded together. I'm guessing you are probably using a much smaller core. The taller the core the more expensive. 17 wide and 13 high.

The core and endtanks at wholesale, which I pay after building X many of them cost me more than you claim the whole thing will cost. This is of course assuming you manage to build and design your IC perfectly on the first attempt. Not very realistic.

"Throw in a few tubes" My guess is that you also just ordered off the shelf bends for your tubing. Sorry but I have to have the bends custom done. Nobody carries bends in 2 3/4 to begin with and they certainly don't carry the tight radius stuff. Call your local mandrel bender and ask him how much to bend one 2 3/4 inch tube on the same radius. Most will not have a radius dye that tight. Next you have to make a jig and cut all the tubes right. Hope you do it right the first time again. Then you have to debur everything, tig weld it all together and hopefully you just happen to have a bead forming tool to make the hose bead. I guess if you wanted a backwater job you could glob drops of weld on the end so the hoses don't blow out.

Now spend a couple hours polishing the tubes so everything looks nice as well.

Okay, you're done with the metal work portion of it. Now lets do the fiberglass duct.

Go to your local fiberglass shop, with your car and the finished intercooler and try to describe what you want done. It has to fit very tightly into the nose of the car and be a part that can be removed. Tell him also that it needs to be designed with a 1/2 inch gap between the end of the duct and intercooler itself because you will be using a commercial grade rubber trim to seal the duct to the intercooler so that only air from the nose of the car passes through it. Also make sure he uses high temp resin because this will get hot. Because of the shape of everything he will tell you it needs to be a two or three piece mold, extra cost. To top everything off ask for a black gel coat to make it pretty. Have fun finding the rubber seal material used. You will also have to order it in bulk.

So after a week or two of leaving your car at the fiberglass place he has finished everything up. Let's pray he understood what you were asking for and executed it right.

Now all that is left before you can use your intercooler is for appearance only to have some custom silicone hose made, regular orange stuff with a black casing affixed to it. This will also have to be a bulk order. Then order the breeze constant torque clamps and a fan and your ready to go. Again let's just hope you did it right the first time and didn't make a single mistake. Trust me I did a lot of this stuff 5 to 10 times before getting it just right.

To conclude the price issue: It's ignorant for you to suggest that a one person effort to make a single copy could do so for anything even close to one thousand dollars. This of course assumes that your time has no value at all. Yes I do make a couple hundred dollars off of these but I'm not a charity and do not claim to be. The simple fact is that if you were a skilled metal worker and fiberglass fabricator you could probably make everything for about $200 less. Most people are not and that's the point. The economy of scale and skilled labor make it unrealistic for each person to build everything themselves. The RX7 certainly did not cost Mazda $30,000 each to build. Now lets see you do it for less. You certainly have a right to say what you believe and I respect that you had enough enthusiasm to build something that you like. The only unfortunate thing is that as a business I have to amoratize all of the tooling and other costs over a smaller number of projected units becasue the 3rd gen RX7 market is so small. If this were for a mustang, eclipse or camaro I could probably do each one for a good deal less, but it's not so that's that.

PERFORMANCE:

This is where you really went off the deep end. Something to bear in mind before you spout about how the ASP IC hasn't "a hope in hell" is that cars equiped with them are a LOT quicker and faster than yours with the "far superior front mount." You should have some data to backup your claim before going into a public forum where the ownes of these faster cars are. Even your 114 MPH isn't very impressive. With nothing other than a precat back crush bent exhaust, everything else bone stock, incuding tires I ran 12.67 @ 111MPH. Also remember using that horrible IC and unfortunately a PFS computer I ran 126MPH as a best trap speed with a stock block. That's 12MPH more than your front mount. Brooks is in the 120's now and I know a lot of others in the 116 to 119 range. BTW radials don't change much in the way of MPH so don't think that is the difference.

You must not be aware of this, but the duct which delivers air from the nose of the car is sealed to IC by a rubber seal. The air passing through the IC can only come from ambient air. Something else you are probably not aware of is that I have temperature probes in the input tube of the IC and the output side. I know what the temp drop is. At speed under WOT the output temp is normally about 4 to 8 degrees above ambient. The input is often over 200F+. I'm sure that those using the large IC can verify to a basic level that after a full pass the output side of the IC feels like cold metal that has been left outside overnight. Put some temp probes in your IC and tell us what you find out, my guess is that your numbers will either be higher or the same, not better as you assume. The purpose of the fan on my IC is to avoid the problem you refer to. Heatsoak from the radiator while at a stop It does a rather nice job I must say. The output temp at a rest stays a few degrees above ambient.

Pressure drop: Unless your IC is 13" tall it will cause more pressure drop. Hopefully we all know what pressure drop is. Generally it means that the higher the pressure drop the harder your turbos will have to work to produce the same amount of boost at the manifold. Temps go up from the turbo as it's efficiency drops at the higher output pressures required because of a higher pressure drop in the shorter intercooler. You could also think of it as a hole in your intercooler bleeding that amount of boost to atmosphere. i don't know which core you used so I couldn't look up the exact numbers. As an example I'll use the PFS core, which I have done before. The PFS core is only 2.5 inches shorter at about 10.5 " in height. With only that minimal difference it has a whopping 3 times the pressure drop of the race IC. It loses over a full pound of boost more than the race IC simply due to pressure drop. My guess is that you used even a shorter core than that so it would fit without removing the bumper. That means that you would have even more pressure drop. A 7" core if memory serves me correctly has a pressure drop of about 3.5 to 4 psi at the boost numbers we are talking about. That means your front mount will require the turbos to put out 3 or 3.5 psi more boost just to overcome the restriction of your core and reach the same pressure at the manifold. I won't even go into the issues of losses through all of the additional bends and new restrictions from the extended plumbing to reach a front mount. I hope you didn't use 2 1/2 " tubes on your IC either. If so it's the smallest point in your airstream and an additional restriction above and beyond just the core.

It appears that you have assumed a few too many things here. I really would like to know which core you used so I could use numbers specific to your IC but again the PFS IC. You assumed your getting more airflow through your IC and that was supposed to be the thing that made it superior, correct? The PFS core at 10.5 x 10.4 x 3.5 is less efficient in lowering temperature at 20 mph of airflow through the core than my race IC is at 5 mph of airflow through the core. I uncharacteristicly apologize to PFS for using their IC to compare but I don't know which one Fritz is using and I'm guessing on a cubic scale Fritz's is no larger or smaller than the PFS core. I'm not trying to hammer on PFS here. So Fritz that means assuming your core is the same cubic size as the PFS core you can have over 400% more airflow through the front mount and it will still not lower the temperature as much as my race IC. My guess is that you do not have 400% more airflow, call me silly.

We have also not talked about your front mount IC preheating the air going into the radiator, a big no no since under race conditions the stock radiator is about at its limit. My guess is under very hard driving you could possibly cause the car to overheat, which as others on the list have experienced could cost you a new motor. The other thing to think about is that you will have to pull your ic out every so often and submerge it in water to see if there are any punctures in the core from all the road debris that will hit it as well as constantly straightening the fins in the IC.

So to conclude this whole thing I think you either assumed way too much or the guys at XS are not thinking things through very thoroughly and giving you false ideas. To be honest your front mount in all likely hood will not lower temperature as much, will suffer from damage caused by road debris and will create more pressure drop, which will raise the input temp and cause the turbos to work harder, causing more backpressure in the turbine side at the same manifold boost pressure and actually shorten the life of the turbos, having to run on average 2 to 4 psi more just to reach the same pressure. While our turbos are producing 10.35 psi to reach stock boost, yours are making 13 to 14 psi to reach stock boost.

It's admirable that you had enough ingenuity to make your own but the fact is that your cheaper IC is just that, cheaper. It will not perform as well and will have significant drawbacks inherrant to it's design that the ASP IC will not suffer from. Let me know when you hit 126 mph in the 1/4 with your front mount IC and stock motor. I did with the ASP race IC and a stock motor.

Kevin's response to another note:

>Other major bummer on the ASP IC is the height, as in most cases it will
>rub a hole in the inner aluminum structure of the hood. Jim Labreck came
>up with a solution to this, which I could have fabricated if anyone is
>interested, or you could do the same thing, as I will share this solution
>with you now:

The top rubbing can be solved by a slight tap with a ball peen hammer on the hood webbing. If people want it the core can be shortened by one ambient row, which would eliminate this issue all together. It would lower the efficiency a small amount, choice is up to the consumer at this point. As mentioned below I have never seen problem with anyone having any rubbing on the bottom of the IC if they use the flathead screws and velcro. Trev remember the IC needs to be able to move since the engine will torque, can't hard mount it to the body.

_________________

Date: Sun, 12 Apr 1998 21:56:51 -0400
From: rotary@mediaone.net

>Reading the recent discussion on intercoolers, I'm curious ; what are the
>inlet and outlet air temperatures, approximately, or in a typical setup, or
>in an ideal setup.

Funny you should ask; I was just reviewing some data from a couple of tonight's runs:

Conditions:	1) Pettit Intake (with Spic Racing enclosure),
		2) ASP Stupid-Large(TM) intercooler
		3) Blah, blah blah, irrelevant mods
		4) Ambient temp 60 F (plus or minus 2 degrees)
		5) Temp measure by stock air temp sensor in upper intake ext..

At a constant 80 mph: 66-68 F
During short 2nd-4th max boost (14-15 psi) bursts: 70-73 F

________________

Date: Mon, 03 May 1999 20:57:14 -0500
From: "Kevin T. Wyum"

Thought I would make this formal since it was only mentioned briefly at the bottom of a previous post on a different topic.

About a month ago Mostly Mazda (M2 Performance) took over the production and sales of both the ASP Race Intercooler and the ASP Medium Intercooler. The reasons were plentiful. I really didn't have the time nor the desire to produce and support the product as it should be. I don't think there is really any question that respectively each intercooler is the best available for the category, (with or without battery). Really a no brainer now that Mostly Mazda / M2 is producing them both with an optional pipe to accommodate the air pump. Anyway, I didn't feel it was good to have the best product and at the same time have close to the worst service with long production times etc. Part of the arrangement was that Mostly Mazda / M2 would keep these items as an in-stock item and maintain the same or better quality to resolve the only real downside, the time delays I previously had. So the following is a rundown of what, where, when and how.

To begin with the ASP Intercoolers, (as designed by me) are only available from Mostly Mazda / M2 Performance now. If it's coming from another source, it's a copy and we all know how well copies normally turn out in workmanship and reliability. Just ask the guy next to you on the driving range who bought his King Cobra II Graphite hump shafts for half price while in South East Asia. Sorry, you can't build quality racing components in a dorm room. Hehehe, somebody posted about an intake that had plastic tubing which melted after being used. Ouch.

Both ASP Race and Medium Intercoolers are now available with an optional charge side pipe that allows the use of either Intercooler with the Air Pump still in place and functional.

Both kits are in stock and available for immediate shipping from here on out. If not shipped within 3 days Mostly Mazda / M2 credits $100 per kit.

The price for a kit is actually fractionally lower now, $1495 in normal configuration, a $50 additional charge for the new charge side tubing for a total of $1,545 with the air pump intact.

Mostly Mazda / M2 also now sells the air pump accommodating pipe separately to individuals who already have one of the Intercoolers for $140.00, this allows any of the previous ASP Intercoolers to fit with the air pump still on the car.

Here's a new twist, they are available during normal business hours. :

Contact, Ordering and support at:

M2 Performance 925-686-9047

________________

Date: Sun, 08 Aug 1999 12:07:33 -0500
From: "Shiv S. Pathak" (Shivp@worldnet.att.net)

I have some good intake temp readings that may interest you. SCC's Project RX-7, with the stock-mount ASP/M2 medium IC, on a 85-90 deg F day, running the high speed east loop of Thunderhill, with 305-310rwhp, in RACE condition (20 minutes of sustained I-think-I'm-going-to-puke hot lapping with Brian @ MM at the wheel), I never saw intake temps go above 150 deg. F. With the stock intercooler, intake temps were nearly 100 deg. hotter by the end of the long 125mph straight (and almost every where else as well).

Also, with the IC upgrade, the air cooled down to a near-ambient 100-105 deg. F almost immediatly (in the turns) during the time you lift off the gas and get on it again. In other words, there is almost no heat soak effect that causes temps to rise and rise over the course of time. Very consistent and very repeatable. The stock IC, on the other hand, would work marginally for the first lap (with intake readings of approx. 225 deg. F) By the next lap, intake temps at that same spot on the track would be 250 deg. F.! The stock IC'd car (which also had a stock radiator), would begin to overheat after 2-3 hard laps. The Project car (with radiator and IC upgrade), despite prolonged lap after lap after lap thrashing, never crept above 210 deg. F. In fact, even while sitting in the paddock, coolant temps were already at 210 deg. F. The 20 minutes of hard driving didn't even phase it.

Try that with a radiator-obsuring, front-mounted IC :)

FWIW, a stock-mounted IC gets fresh air ducted to it from the front of the nose (not underhood heat). With a large enough core surface area, you don't need a lot of air flow for it to operate at peak efficiency. Also, with less (and more direct) intake plumbing, it *should* have less pressure drop than a front-mounted IC system.

IMHO, if you drive your car makes good hp, and you drive it moderately hard in hot weather, a front-mounted IC is not the way to go. This is probably why the R34 Nissan Skyline we tested a little while ago began to overheat after just a few hard laps. No harm done though. Unfortunately, the water seals in our rotary engines aren't so tolerant.

_________________

Max Cooper has a nice page on the M2 (ASP) Medium IC, with pictures, details, etc.

_________________

Date: Tue, 01 Feb 2000 22:27:19 -0500
From: Spathak

FWIW, I just A/B tested the M2 Medium and new M2 Large ICs. The new Large IC has the same dimensions as the old Large IC. However, the core design is different. Whereas the old core had fewer air channels and wider external turbulator rows, the new core is identical to that of the M2 Medium IC... just longer. Here are the results...

Testing Conditions:

Ambient 63-65F
Boost level:  12psi @ sea level
Output level:  ~300rwhp


- --Medium IC--

Intake T at 50mph cruise:  67F
Peak intake T in 3rd gear WOT run:  98F
Peak intake T in WOT 0-80mph run:  105F
Maximum pressure loss: 1.1psi


- --Large IC--

Intake T at 50mph cruise:  70F 
Peak intake T in 3rd gear WOT run:  92F
Peak intake T in WOT 0-80mph run:  99F
Maximum pressure loss:  1.1psi

Crooked Willow

Crooked Willow has announced their new intercooler. This mounts more or less in the stock location and is compatible with most after-market intakes, but it does require battery relocation or miniaturization.

Includes polished aluminum pipes, carbon fiber or aluminum inlet duct, silicone pipe couplings, high-quality hose clamps, mounting brackets and hardware. Elbow not included (available on request, $125).

Email Duane Krumweide or phone 858.775.4292.

CWC Intercooler CWC Intercooler

Polished and unpolished shown:

CWC Intercooler

Shane Racing

From: Steven N. Burkett:

Danger. Danger. ;-)

The SR stock mount IC is NOT bolt in. Not even close.

Question: Anyone installed this sucessfully? Tips?

Comments:

The core *is* a lot bigger then the stock IC. And it more or less fits in the space where the stocker is located. But:

  1. It won't settle all the way in, because the bottom is square and hits the fans left fan.
  2. It won't rest properly against the stock plastic air duct intake.
  3. Even if you manage to fanagle your way past one and two, the stock IC to intake elbow hose will no longer be shaped right to connect them up.

Grrr....

One of the main reasons I chose this IC was stock mountability. Oh well. Looks like what I expected would be a one hour job is leading to a "fabricate an entirely custom ducting and intake system."

______________

Shane also has an horizontal mount IC. The possible issue with this is that you would also need to get a vented hood that had the vents in the right place so that air would flow through it.

Pettit

Date: Mon, 23 Mar 1998 21:34:20 -0600
From: drchuck@petronet.net (Chuck Broussard)

I just finished installing the ASP large intercooler so my medium sized Pettit Intercooler is for sale. It has been in use for one year. Also, the black fiberglass air ducting from the nose is a piece of crap and did not fit any where close to air tight. I tried to fix this by sealing it with black silicone. Well the air seal worked but I also made a mess of the intercooler in the process and the intercooler(and ducting) will take some time in cleaning up.

Opinions about intercoolers: If I were buying a new medium sized intercooler, I would not buy Pettit's. The intercooler itself is fine but it is the fiberglass ducting that really sucks. IT DOESNT FIT. Spaces between the intercooler and the ducting is not good. I've seen this also with Peter Farrel's intercoolers. Pettit needs to talk to Kevin Wyum about making quality ducting. The ASP ducting fits and seals all the way aroung the intercooler. If I were buying new and I didnt want to worry about moving the battery, I would buy the ASP medium (assuming the ducting is the same quality). Sure, there may be a little wait, but that's what I would do. Unless, you are very good at making things fit smoothly and cleanly by fabricating your own little modifications. I would recommend all Pettit and Peter Farrell intercooler owners to buy whatever Kevin uses to seal his ducts and use it.

Anyway, this intercooler new costs $1300.00(for that much, you shouldn't need to make the duct air tight). I am selling the intercooler, the ducting,two blue hose connectors, and two hose clamps.

PFS

Date: Tue, 25 Apr 2000 17:44:11 PDT
From: "Rich Spear" (rdspear@hotmail.com)

The West Penn RX-7 Club had its first sporadic dyno day last Saturday. You can check www.rx-7.org/events/dynoday2000.htm for pix, and hopefully graphs as soon as the download process is completed.

Here are a few results/finding for comparison:

IC Upgrade:

I took 2 runs to establish a baseline, and then replaced my stock IC with a PFS unit (about two hours between runs - 2:00-4:00, so conditions were near identical). All other settings (manual boost valve) remained the same. The dyno had a fairly sizeable fan, the output of which was nearly identical to the size/shape of the IC ducting, and placed right up to the duct. I would estimate it simulated the flow at 40-50 mph.

Other mods: N-tech intake, 3" SS dp, PFS cat-back, Pettit ECU upgrade (see next post), Unorthodox main underdrive pulley, 11lb flywheel:

Stock IC - 10.8 psi - 283.9 hp  247.7 ft-lbs
PFS IC -  11.2 psi  - 299.3 hp  264.9 ft-lbs

(Yes, I know the boost gauge isn't accurate to 0.1 lbs, but they are my best estimates from the passenger seat and the relative difference should be within .1-.2)

So, the PFS has about .4psi less pressure drop than stock, and is good for about 15 hp/17 ft-lbs.

________________

Date: Wed, 19 Apr 2000 11:03:24 -0700
From: "Sam Tarbox" (Sam.Tarbox@xilinx.com)

I own the PFS red, I would never buy one again. It works, but the top in top out design makes it a PITA to work on the front of the engine, or even fit an after market AST. The duct is okay, but if you run anything other than their intake you have to block off the hole. Don't get me wrong, I like their products, I would just not go with their IC again.

Mazda Competition Parts

From: petel@electroimpact.com (pete lombrozo)
Date: Tue, 28 Jan 1997 18:39:29 +0000

I talked to randy at Mazda comp today about their new IC. It fits the stock location (no mods) has all the correct brackets and nuts to fit the stock hardware ducting, and costs $372.60 !

It is made by Fluidyne, is all aluminum, and is more efficient than stock.

They have no info on performance yet, so if you buy one you have to fill us all in on "percieved" improvement.

______________________

Date: Wed, 30 Jul 1997 13:27:18 -0800
From: Alex Peyzner

I have seen the Mazda Comp unit at Mostly Mazda.

It is about the size of a stock IC but constructed better. It has the same number of rows and fins.

The price is right, but the benefits are not justified IMHO.

Blitz

Date: Sat, 22 Jan 2000 21:28:10 -0800
From: "Emilio G. Littel" (emilio@littel.com)

> The Blitz is a work of art, but not a great value. With a 4 inch thick
> core, it should have very low pressure drop. It also may work OK with
> a slightly mod'd stock duct.

The fit to the factory duct is excellent without modifications. Actually, a strip of 1/4 inch thick rubber weather striping around the side edges provides a nice seal. Also, the IC comes with the necessary silicon rubber hoses to attach to the stock piping. It takes very well to being installed with the stock air box with only one minor modification to it the air box itself: a 1/4 inch triangular trim to the inboard, rear mounting tab.

You are right to say it is not the best value. However, one pays extra for looks, finish quality and style (in a "snooty & ricey" sort of way) ...=8^] It is a very nice unit nonetheless and it fits my particular application well: stock looking engine bay with fresh air supply to the stock airbox from the nose of the car, and a "stealthy", boost actuated, IC water spray system.

RX-7 Fashion

The RX-7 Fashion IC is a front mount IC based on an Apex'i core.

Chuck gets a bit defensive here, but there is some good info on his IC. --Steve

Date: Thu, 2 Jul 1998 20:20:14 EDT
From: TAKESHI988@aol.com

RX-7 Fashion

I never advertised this IC kit on the list but since someone brought it and and some people were discussing about it, I guess I am forced to jump in.

First, about the price. Not everyone thinks that Greddy Elbow is a necessrity. It's more for the looks and only if you want to put two additional injectors but most people won't find that necessary. That's why I include it as an "OPTION" and it is. The IC will fit on the car without that elbow. There is no hidden cost there. About the blue silicone hose, it's an "OPTION" too. The kit comes with regular 3 plied orange silicon hose. If you want to look cool and get the better silicon hoses, it's up to you. There is no hidden cost there.

About pressure drop, Adam Saruwatari is using the Apex core and run 9 sec. How come he is not using an ASP one? I am wondering. Dont tell me he is not trying to squeeze the most out of his car. If the Apex core has so much pressure drop, why is he using it?

The Apex C1 core Adam is using is 5.3 inch thick which might cause overheating on the street but in fact I choose the Apex C2 core which is 3.5 inch thick to correct that problem.

________________

Date: Thu, 2 Jul 1998 20:35:27 EDT
From: Stephen J Lee

First, I'd like to commend these guys for making a good looking IC for what appears to be a great price.

Second, if you look around at Steve Cirian's site (Wyum's comment on ICs) and several other sources, you would see that their IC is not quite optimal. You want the core cross section to be as large as possible but, as the Fashion site says, as thin as possible. Hence, you want it tall. Fashion make up for it by making the core REALLY long. So, I guess what I'm trying to say is that the Fashion appears to be a great (best maybe?) value for the non-racer. If you are a racer and need that every bit of efficiency, it may not be the best choice.

Disclaimer: I am not going to try and build a better mouse trap for a lower cost. If you want a huge IC, call Spearco, they have some big ones with the endtanks already on. Or make a set yourself. That having been said, my site has some pics of endtanks that I designed on AutoCAD. If they aren't too expensive, I'm going to have a set made up for myself. If you want one, I'll just tell the CNCer to fab another set and send it to you at cost. No duct, no core, no tubing, just two tanks. You find a welder and do all the work.

If you want to discuss the merits of my endtanks (they were NOT designed with a computaional fluid dynamics program like SURFCAM, PowerFLOW, etc. which would cost you over $10,000 for the IC), feel free to email me.

Denso

Date: Fri, 26 Jan 2001 19:37:41 -0800
From: "Max Cooper" (maxc@speakeasy.org)

> any of you guys heard anything or used a denso intercooler on a 3rd gen or
> other??  ive had one offered to me with the specs that it
>
> Measures 20 inches wide by 13 inches tall by 2iches thick. Not a direct bolt
> on but it is easy to install and works great.Has very small dent on top of
> the first tube runner of the intercooler ,its about 1/4inch deep by 1inch
> wide.  With the endtanks it measures 29inches wide with of coarse 3inch
> inlet and outlets

13" tall and 2" thick does not give a lot of internal flow area. That means it will most likely have a lot of pressure drop, which is bad. So bad is pressure drop that trubo expert Corky Bell says that pressure drop is the most important factor in choosing an intercooler.

Here are the internal flow areas of some intercoolers for comparison:

Denso:             13   x 2   = 26 in^2
Stock:             11.5 x 2.5 = 29 in^2
GReddy (front):    10.5 x 4   = 42 in^2
Greddy (stock):    12.5 x 4   = 50 in^2

Now, this number is not the only thing that determines pressure drop, as the construction of the IC core plays a major role. And while pressure drop is really, really important, that doesn't necessarily mean that the best choice is the one with the lowest drop. For example, few would argue that the GReddy stock mount IC is the best intercooler available, because it is significantly smaller than some others and thus probably does not do as good a job at cooling.

That said, I do think it is safe to assume that the Denso core you are considering is not a good choice if performance is your goal. It does not even have the flow area of the stock IC.

Other Vendors

Date: Thu, 12 Mar 1998 06:38:36 PST
From: "Jeff Witzer"

>Brooks Weisblat wrote:
>
> I was browsing some japanese sites and came across some pictures of
> 3rd gens that seem to have a radiator and intercooler kit that is
> together.....
>
> They are arranged in a V fashion in the mouth of the car....there is
> no duct....they come together in a way that they both form the
> duct....
>
> Hard to explain....here is a 
picture.
>
> anyone know anything about this???  who makes it? how much??  and
> most importantly....is it any good?
>
> it looks good and in theory should performa well....if that IC is
> big enough....

>Kevin T. Wyum responded:
>
> Pretty interesting. Coulple of things I can't figure out. How would
> the fans fit. Where the air would discharge to in a semi stock
> engine bay and lastly would the radiator get enough air being on the
> bottom like that? Big points for creative thinking however it works
> out.

I would assume the fans fit on the bottom of the radiator to continue using the pull-through type. The warm air would bathe the bottom of the engine, no? I don't think that it matters that the radiator is on the bottom air-flow-wise. The volume of air that enters the mouth of the V is pressurized by the movement of the car and held in by the sheetmetal sides. Once it enters the mouth of the V it either goes through the intercooler or the radiator. The distribution is dependent on the relative resistance of one to the other.

My big question is that of intercooler heat soak from the hot radiator below, especially at low speeds or in traffic conditions.

I know that Cam tried this configuration in the race car a while back... even included a splitter in the middle. He determined that straight up was better...

If I/C heat soak is not a problem, and since Kevin is working on an I/C that's tipped forward... could fitting an ASP mondo intercooler into a configuration like this work? ...especially with the exit ducting? No intake duct required!

Do It Yourself

From: Stephen J Lee
Date: Jan 4, 1999

> Do you have the part numbers from Spearco handy? Or would they just know
> what I am talking about if I call and ask for the cort that ASP uses?

The part # is: 2-180

They remembered the ASP core because Mr. Spears mentioned that he didn't like cutting off only on ambient row for Kevin.

As far as the price is concerned, I got a 20% student discount. The core price for the above is $432 and I think they charge $20 for cutting off an ambient and charge row off and welding a plate. So you're looking at $452 without shipping.

I almost did this myself but I caught up in some other stuff. I talked to Incon about the silicon tubing so I would recommend them. They advertise in "Racecar Engineering" if that means anything to you, it does to me. They're number is 440-234-2450 and they are in Cleveland, Ohio.

________________

Date: Fri, 5 Jun 1998 02:21:24 -0700
From: "Hung-Jen Hung"

I think I can share my experience with any of you who are interested in making your own intercooler. I made mine in '96, therefore the parts number described following is from my 1995-1996 Spearco Catalogue. Please double check with Spearco, 818-901-7851, in case they changed the part number.

The core I adapted has part# 2-192 and the size of the core is 3.5"x9.5"x12.4" with flow rate 630. End tank size is 3.5"x9.5"x3.5" on both sides and the diameter for the hose housing is 3" that locates one inch below the top. Because I am using an ARC intake that has similar size to stock air box therefore I believe the wider core can be used if you have air intake such as PFS, HKS, K&N ...etc.

Please visit my web page and click on [Intercooler Project] for the measurement drawing and photo showing actual intercooler on my car. At that moment, Spearco gave me two choices on the core thickness, either 3.5" or 4.5". After the measurement, I ended up going for 3.5", and that seems a right decision, because you need some room between the intercooler and pulleys for the coolant air separator tank. Forgot to mention that, yeah, I relocated my battery to the passenger side storage bin.

To prevent the intercooler from putting weight on the fan motors, a 1-1/4" rubber spacer is used on each side. A note here, no mounting bracket comes with the intercooler, so I had Tri-Point make the brackets for me, and also intercooler pipes and air duct shroud. The cost of intercooler is $495 including core+end tanks and Tri-Point charged me about $550 for all the things they did. I first thought Tri Point charged too much, but after seeing how smooth on both inside and outside of pipes also the superb welding job they've done I have no complaints, only compliments.

Speaking about efficiency, after normal freeway driving, I can put my hands on the outlet side of pipes w/o feeling burned. For autox events, if I spray some water on the inlet pipe, not too much, I can put my hands on it as well. I was thinking to attach a temperature meter on each side of pipe to see the temperature drop difference as someone suggested before, but I cannot find any of the meter could handle temperature up to 150 F. Anyone knows where to find one?

I don't have any theory to backup my intercooler as ASP does. I just made the measurement by myself and Spearco suggested me the size that I could possibly use, hence please don't question me on any theoretical topics.

Discussion of Front-Mounted ICs

From: Steve Cirian
Date: April 20, 2000

>>The intercooler duct MUST be sealed to the IC.  If not, then the air will hit the 
>>face of the core and "boiunce" off of it instead of going through it.
>
>Very interesting discussion, I wonder how all this would apply to a front
>mount, like say Greddy which is in an open area without ducting.
>I wonder if the Grreddy, Blitz, HKS, etc... front mounts would benefit from
>a duct, or am I completely off base with this.

I have never seen a front mount that was ducted or sealed to the front bumper. (That does not mean they don't exist - I personally have not seen it.) That is one of the things wrong with the front mounts. (Not that there aren't some things right with them too :-)

Other issues people have pointed out on the front mounts:

  1. They block air flow to the radiator. They also heat up the air going to the radiator. The 3rds have enough cooling problems w/o interfering w/ the radiator.

  2. There are a lot of bends in the tubing on the front mounts. Corky's book said that there is a loss for every bend. Don't have the book w/ me, so can anyone provide the numbers? I counted 4 x 90-degree bends on the inlet side alone of one of the front mounts on a Japanese tuner web site.

  3. Unless you put screen over the opening, it is susceptible to rocks, clogging by bugs and other debris, etc.

  4. Depending on how it fits, it could block the cold air source for your cold air intake.

  5. Longer plumbing might add lag or increase pressure drop.

  6. Corky said that the cores should use the shortest tubes possible. Most front mounts I have seen use really long tubes compared to the stock position ones. i.e.-

    Good:

    	| | | | | | | | | | | | | | | | | |
    	| | | | | | | | | | | | | | | | | |
    	| | | | | | | | | | | | | | | | | |
    

    Bad:

    	___________________________________
    	___________________________________
    	___________________________________
    

    The "Good" layout is possible with a front mount. I just haven't seen any. The end tanks would need to sit on top of and on bottom of the core. Inlet and outlet would have to go to the sides. With a core that long, you would also probably want to go to a split inlet (see "THE" book :-).

(You may have noticed I've become a huge fan (no turbo pun intended) of Corky's recently - if at all interested in this topic read the book ASAP!)

_______________

Date: Mon, 28 Jul 1997 21:20:45 -0400 (EDT)
From: Francois McKellar

For you bargain hunters out there, I chose to go with a custom front mount intercooler from Spearco. I studied the flow charts, choosing the best flow with the best efficency and least pressur drop ~1.5 psi).Efficency is 60% at 10MPH and 80% at 20MPH, being front mount allows this unit to easily reach these ampient flow rates. At $430.00, the price is much more affordable(than buying it from a wholesaler, but you have to get your hands dirty) and often better in performance (compared to the PF intercooler flow charts - Spearco unit as well). Mounting the intercooler up front was relatively simple, with approx a day to do it. It involved removing the fibreglass energy absorption bumper (I'm more worried about getting hit from behind, what I can't see coming) I used 2 3/4ID plumbing, which does increase the boost lag (also due to longer plumbing and large core than stock), but when it kicks in the difference was amazing! You can actually feel a dramatic difference in intake and exhaust pipes. I gained approx 1psi of boost, and EGTs dropped more than I expected. If anyone would like the info, feel free to mail me. For those who are curious, the core is 3.5" by 7.9" by 12.88".

_____________

Date: Tue, 29 Jul 1997 08:25:12 +1000
From: eltang

The best intercoolers i have come across are those that run off the front of the nose.

There are many Japanese RX7s that are using these configurations. All of you all might know the advantages of running the IC of the front. This setup requires that the stock radiator to be repositioned in a stand-up fashion. Most Japanese tuners sell IC kits, the only thing required is the repositioning of the intercoolers.

If using intercoolers of the front nose you can really go up to the big sizes like 36inches in length alone!!

_____________________

Date: Tue, 29 Jul 1997 03:37:31 +0000
From: "Dave Girvan"

3rd gen intercoolers already run off the front of the nose. Just because they aren't visible from the mouth of the nose, doesn't mean that they aren't front mounted. Sure, on a Turbo II, this might make sense, but I just can't see how a streetable 3rd gen would benefit from such a modification. There are several excellent aftermarket IC's out there that are more than capable of cooling the intake charge, at the upper boost limits of the stock turbos. Some of the big racing IC's take that a step further, by being able to dissipate the BTU's generated from running obcene amounts of boost on properly prepped rotaries. An out in front, all you see is intercooler filled mouth, on a street drivin car, is just asking for trouble, in my opinion. I'm not going to spend lots of $$$ for an IC, to have it dented and dinged, from rocks and other road debris. Now for a pure racing 3rd gen, maybe... ;-)

_____________________

Date: Tue, 13 Jan 1998 01:05:15 -0800 (PST)
From: NetBlazer

Fritz, we agree on one thing, that both a front mount, and an internal IC both have problems. Where we differ is I think the front mount has major problems that are not easily taken care of, and the internal variety's problems can be solved more easily (yes it does take more than adding a fan :)

I am bored, and can either do some programming at this point (read work) or attempt to go into more detail...

The front mount IC looks cool, and the women love it. It also attracts the attention of bugs, and rocks (how many people have inspected their 'front mount' oil coolers at even 20-30K miles? How bout 70K...If yours look anything like mine you will know what I am referring to.

I have not installed a front mount IC, but hear (correct me if I have heard wrong) that you need to lose the fiberglass inner bumper (the only real support you have in the front if you can call it that)

Now for performance...yes it gets more direct air flow, and as such should cool the charge closer to ambient. It also discharges that now warm (hot?) air directly into the radiator, and on into the engine compartment. (sounds like you will be needed some of those custom inner coolant seals sooner than most, although being farther North than most of us on the list, you don't have to worry about it as much as someone say in Texas.

The core itself is Longer, and shorter, so it will be an intake restriction. (which would you rather breath through, a 2 or a 3 foot long straw? ) Since it is shorter there are less 'straws' to flow through. And as Fritz metioned above, the plumbing is much longer to and from the IC causing further flow restrictions.

Now where do you fetch your cold air from for the intake? If you are unlucky enough to not own an R1, then you can use the spot where you should be putting a second oil cooler. If not, then you either cut a hole in the hood, or suck hot air in, either directly from the engine compartment, or from in front of the radiator. If you do go the hot air route, remove your air pump, or it could cause you severe other problems when it siezes taking the water pump belt with it if not caught in time.

Of the problems listed above, the biggest is going to be the hot air into the radiator. This can be solved, but will require some more major modifications to the bodywork (Read in addition to the removal of the fiberglass inner bumper)

To sum up the front mount portion of this: IMNSHO if you want the car to look cool like all those supras, and only plan to race for 1/4" mi AND live in an area where you won't ever be racing in 90+ degree weather, go for it.

Now on to the internal IC. Drawbacks: no-one can see it from the outside, so it only looks cool when you open the hood, and someone says 'wow you have a huge radiator', it does not get enough air flow as its feeding off the air supply designed for a stock rx-7, with the stock tiny IC, running no more than 10lbs boost. One way to get more airflow out of it is to install the supplied fiberglass scoop (some..okay a lot of cutting required on the scoop :) This blocks quite a bit of one side of the radiator, and is potentially worse than using a front mount IC as you just created a low pressure zone, which could suck hot engine air through the radiator (backwards) (this is a theory and not a fact at this point, but I wouldn't use it, and have several of them left over from ASP ICs I have helped install. They make marginal trays for loose parts on the workbench though :)

Other major bummer on the ASP IC is the height, as in most cases it will rub a hole in the inner aluminum structure of the hood. Jim Labreck came up with a solution to this, which I could have fabricated if anyone is interested, or you could do the same thing, as I will share this solution with you now:

Remove the stamped steel cross brace the IC sits on, and replace it with two pieces of aluminum (I am thinking a piece of extruded channel aluminum) one on either side welded to the ICs end tanks, and bolted to the places the stock cross piece bolted. They would be welded to it in such a way as to lower it slightly, and serve to lock it in place more efficiently than the included velcro. This would prevent the dreaded hood rubbing, plus wouldn't wear any holes through the IC (top or bottom which seems to be a potential problem). Cost of the fix would be mostly in time trying to get it positioned just right, and in the equipment to polish the aluminum :)

As for the air flow issue, I have a very good solution, which makes very few compromises. Granted I had help coming up with this (Thanks to Troy Wilson for the org concept of moving the radiator) and thanks go to Jim Labreck for his advice on fiberglass ducting design, and his ideas on how to make fabricating an intake splitter easier, and for finding a better place to relocate the relay box to (about 9 wires need minor surgery). (I was either going to raise it up a little, or cast a place for it to sit on its side in the top of the duct) Jim's solution, and pics + instructions can be seen on his website. http://www.activepages.com/chuckm/rx7/index.htm

By moving the radiator a little over an inch and a half, and by removing the plastic blocking insert you can open up the intake/IC intake area considerably. Now, the duct for this is complicated if you wish to use the full area opened up, without adding drag, and restrictions, but I have been hand bending, cutting, and fitting aluminum sheet, to make a fiberglass mold off for quite some time. I am learning quite a bit a long the way, and only wish I had more time. The major hurdle is past, as I got the most complex transition done (the curve of the part that goes where the stock IC duct went (larger opening) is different than the curve of the rest of the duct).

The duct comes down, and creates an air seperator in the nose, allowing the full amount of air that could freely flow to the radiator go there, and the rest to the IC, and air intake (most of this air would have normally hit the plastic blocking structure in place, and circled back around, causing turbulence, and back flow)

Although I plan to do some drag racing, most of my time will be spent on the road course, or doing top speed runs on rural unpopulated (except for the damn deer) backroads. I choose the internal modified IC for this application.

Hope this somewhat biased, but AFAIK factual information helps someone out there on this snowy (in my town) night.

Intercooler Fans

Date: Tue, 21 Mar 2000 08:12:07 -0500
From: "kevin kelleher" (kellehkj@earthlink.net)

Here is a properly sized fan.

For a daily driver, hot city trafffic will cause the massive IC to build up heat. Given the limited engine bay ventilation, the coolant rad fans will actually back feed the IC with hot air ... I have measured this occurance. Even moving at low speed, rad fans (AC) will impede IC airflow.

SCC showed that a chilled massive IC will cool intake charges alot thru 3rd gear run-ups, but will reach equilibrium at the track at a higher temp. If preheated, it will take some time at speed to remove this heat.

The fan will make the car a bit more responsive after stop and go traffic , esp on hot days, AC on, etc. Could relay it off the rad fans, with a manual on-off override switch.

Summit

SPAL Auto Accessories

PermaCool

Flex-a-lite

___________________

From Spencer Hutchings:

I mounted two 4.5" 12V fans on the back of it. They move quite a bit of air for there size and have held up quite well for the past two years. You can really feel them pulling in air on the front of the intercooler if you stick your hand in the intake. The fans come on as soon as I turn the key and stay on until the key is turned off. I did put a 1AMP fuse on them, just in case, but have never replaced it.

Intercooler fans

Intercooler fans

___________________

Date: Wed, 8 May 2002 23:44:04 -0400
From: "kevin kelleher" (kellehkj@earthlink.net)

> I want to add a fan to my intercooler (m2 big). I don't really want it to
> run all times the car is on (I prefer a manual switch or some sort of
> temperature switch). I also don't really want to run a bunch of wires into
> the cockpit. If I do have to run wires into the cockpit, it needs to be
> very neat...............

simple adj temp switch:
http://www.assetmfg.com/index.html

fancy IC temp vs ambient controler:
http://www.autospeed.com/A_0589/page1.html?src=suggestions
http://www.autospeed.com/cgi-bin/browse.cgi?category=705&

air-flow (motion) switch:
http://www.autospeed.com.au/A_1043/P_1/article.html

could also use 'asset' kit to trigger low speed fan, thru the diagnosis plug ... ground TFA terminal.

Intercooler Ducting

From: Steve Cirian>BR> Date: April 20, 2000

Maximum Boost by Corky Bell said that the duct inlet should be at least 1/4 the size of the core. Anyone know how the M2 big IC and duct relate to this number?

You want the duct inlet to be smaller than the core. Just not too much smaller.

______________

From: Shiv Pathak
April 20, 2000

FWIW, I have talked to Corky since I wrote that IC comparison test story. Appearantly, he thinks the 4:1 duct rule may be a little excessive-- meaning that a smaller duct can be used with negligable reductions in cooling efficiency. I recall him saying something on the order of 6:1. I'm just going by memory here so don't hold me (or him) to it...

_______________

From: Max Cooper (max@maxcooper.com)
Date: April 21, 2000

There are two important ways to think about the whole ducting issue:

1. IN THE ABSTRACT

In the abstract, where you don't have to deal with the actual dimensions of the car, etc. there are some easy rules to follow. The first rule is that you should have a duct. Just having an intercooler (or radiator, or oil cooler, etc.) sitting in some stream of air is not very efficient. The IC presents some resistance to flow, so the air will just try to get around it. Having a duct captures the air that flows through its inlet and forces it to go through the IC core. However, it isn't quite that simple and that gets us to our second rule of thumb: the inlet of the duct should be smaller than the flow area of the core. That is to say that the duct should have an opening of some size and then expand to meet the core of the IC. The reason to not make the duct inlet as large as the core is that the air will "spill over" at some speed rather than passing the through the core. Because the core provides some resistance to flow, the duct will "fill" with air and eventually spill over the edge as speed increases. Cooling is greatly decreased when this "spill over" occurs. So, it turns out that it is more efficient to make the duct inlet smaller than the core. I imagine that ducts end up being tuned for particular air speeds and for the aerodynamic drag properties of the core.

2. IN REALITY

You don't have much room to put a duct on a front mount IC. I would think that the best you could do would be to have the duct inlet equal to the opening at the front of the car and have it quickly expand to the size of the IC core (this assumes the IC core is substantially larger than the opening at the front of the car). Then have a duct between the IC and Radiator that transitioned from the full size of one core to the next. Another alternative would be to split the opening up into two parts - one that went straight to some portion of the radiator and another that passed through the intercooler and was then ducted to the rest of the face of the radiator.

This does sort of highlight how a front mount IC may not only be heating the air before it gets to the radiator, but also reducing the amount of air itself. Both are bad, but I think the reduced amount of air is often overlooked.

Water Injection and Sprayer Systems

From: Isaac Turk (iturk@erols.com)
Date: Fri, 17 May 1996 12:00:11 -0400 (EDT)

[Khoi's] next project has been building a IC spray system. His car is setup now so that he hits a red button on his shifter to engage the cool spray system which puts 2 mist sprayers into his stock IC. With out the system the drop from the IC was 40-55F testing at all types of boost psi. This translates into the turbos seeing 100-110F air temp (outlet temp from IC). When the spray system was engaged we saw a 30 degree additional drop. That was with 75F water (outside temp). We are going to dump ice water in soon and get the new measurements...we are hoping to get an additional 50 degree drop to give a 100 total drop...(maybe dry ice later...hehe)... someting you have to usually spend 1-1.5K on an IC to get. Yes you have to change the water often, but hey...it's free...it's cheap, and been effective so far. Call Khoi Ta at (703)-968-6272 on fridays at his shop (Euram Motors, Chantilly, VA) or (703)308-1127 M-Th at his other company...see you at the next RX-7 meeting!

__________________

Saved this, but didn't save the address of the person who sent it. Sorry! --Steve

Intercooler Sprayer Ideas

The first selection is from Eric Typpo as written in the MDSOG Newsletter a few years back. He really knows a hell-of a lot about the DSMs, so give him an email.

From testing I've done with a pyrometer, one weak point on the Diamond Stars with increased boost levels is the intercooler. Under sustained boost, it heats up quickly, heat soaks and cools down slowly. Alamo Autosports only claims a not very spectacular 63% efficiency @ 16 psi. for their intercooler UPGRADE, also implying that the factory intercooler is pretty inefficient at cooling the intake charge.

Spearco makes a device which sprays fluid on the intercooler to increase intercooler efficiency, but at $125, I have always been too cheap to get one and did not have space for the tank to hold the fluid. Therefore, I decided to make one myself using the rear washer mechanism and about $10 worth of parts. To make the conversion yourself you will need:

1. About 25' of 5/32" vacuum hose.

2. A washer nozzle to spray the fluid across the intercooler. I found one at Pep Boys (Motormite P/N 47110) which is designed as a replacement for GM midsize cars. It is perfect because the nozzle is at a 90 degree angle to the fluid input which makes mounting on the intercooler shroud very easy.

3. A Whisper one way aquarium air line valve.

4. A vacuum line tee.

The washer mechanism is at the very back of the car, behind a panel in front of the driver's side tail lights. Remove the panel(s) and disconnect the original hose and attach the new vacuum hose. (squirt all the old fluid out first since it will drain when you remove the old hose). Route the hose out the car through one of the grommets around the hoses that drain the perimeter of the hatch on either side (I did it on the driver's side). Run the hose beneath the car, securing the hose to the fuel/brake lines with wire ties along the way. Remove the shroud in front of the intercooler and drill a hole as far away from the intercooler as possible (to increase the dispersion of the fluid), insert the nozzle and connect the hose to it.

The problem at this point is that the hose will continue to siphon the washer tank after it is used, so your first application will also be your last. To prevent that, I created a siphon break by putting a tee and a short length of hose with a Whisper one way aquarium air line valve at the end, on the hose at a point above the washer tank at the back of the car. It is important to create a fairly sharp bend in the hose and put the tee at the top of the bend for maximum effectiveness. The one way valve prevents fluid from squirting out under pressure, but air is pulled in to the hose, breaking the siphon after the washer is turned off. (The end of the valve that you CAN'T blow through is pointed toward the tee.) Use the sprayer for a second after filling to make sure that any siphon that was created during filling is broken.

Overall, it is a cheap way to regain a few of those horsepower lost to summer heat by increasing the efficiency of factory as well as upgraded intercoolers. Spearco sells a pressure switch for $36 which could be used to make the sprayer activate automatically under boost, but I have not experimented with it yet.

Silicone Hoses

Date: Tue, 07 Oct 97 11:05:36 -0500
From: "Linthicum, Sandy" (linthias@sandy-ntws.usps.gov)

Silicone Hosing

_______________

From: Mike Putnam (putnam@spawar.navy.mil)
Date: April 11, 2000

Order them online from McMaster-Carr the exact catalog page number is 168. When you get to their web site do a search for "Constant-Torque Worm-Drive Hose Clamp"

McMaster-Carr accepts credit cards and it typically takes them a week to get things to you. By the way McMaster-Carr is one of the least expensive sources for high quality silicone or Viton vacuum hose.

_______________

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: Tri-Point Hose Kit Tri-Point Hose Kit

_________________

Date: Mon, 27 Oct 1997 00:41:07 -0800
From: "Drew"

>Where have people been getting their silicone vacuum hose from?

Their (?????) tel nbr is: (714) 637-1155.

They have straight turbo hoses in 1/4 " ID increments from 1 1/4" to 2", and 2 1/2" to 3", and 3 1/2". They come in 3 or 5 ply.

They have 90 degree turbo hoses in 1/4" increments from 1" to 2 1/2". They come in 3 or 5 ply.

This is from their catalog. If they don't have what you want, just ask if they can get it or know a source.

-----------------

Rotary Perfomance also has silicon vacuum hose:
Rotary Performance
Garland, TX
972-520-3335

----------------- Mazdatrix
Signal Hill, Ca.
(562) 426-7960
http://www.mazdatrix.com/

----------------- Auto Enhancement
Fresno, Ca.
(209) 438-5700
Ask for Ian and let him know what you need.

I get mine from Auto Enhancement in Fresno, CA (209) 438-5700 If you are doing the whole car just ask for Ian and let him know what you are doing and he will get you the right stuff. I think I got 20ft of 4mm and 20ft of 6mm and that was plenty with some extra left over. I replaced every single line. Don't forget to tie wrap every end also. It takes me about 12 hours to tear it all apart, change the lines, re-assemble and test.

I also did the rubber turbo joints. That stuff was not cheep, over $7 an inch. But I have not blown a boost hose since I did it.
Spencer Hutchings

-----------------

Landmark Motorsport Orange, Ca.
(714) 637-1155
Ask for Sharon Angle, say that Sandy Linthicum recommended them to you!

------------------ Options Auto Salon
Glendale, Ca.
(Currently having problems with supplier, plan to buy directly from manufacturer in the future.)
(800) 678-2886

Clamps

Date: Tue, 07 Oct 97 11:05:36 -0500
From: "Linthicum, Sandy" (linthias@sandy-ntws.usps.gov)

Clamps

_________________

Date: Sun, 28 Mar 1999 20:08:01 -0600
From: brad barber (bradrx7@swbell.net)

> continuous tension band clamps that cost about $8 each.

Try this: http://www.breezeclamps.com/cnstpage.html

__________________

From: Steve Cirian
Date: May 13, 2000

Alatec Products distributes Adel Wiggins clamps and connectors. 800-541-2345 or 314-639-1300

I saw the Adel Wiggins tube connectors on the Cadillac Northstar LMP race car's turbo pipes at this spring Chicago Auto show. I just knew I needed them. I called Alatec and found out they were about $100 EACH!!!, and I would have needed 8 of them. I just knew I didn't need them :-)

Besides, they are intended for connecting pipes together when the pipes have small "flanges" built into them. These are not for pipes intended to have silicone couplers. Use the Breeze clamps mentioned above for the standard pipe and hose setup.

Adel Wiggins may make other clamps that would be appropriate.

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