Curious if anyone has ever attempted a homemade intercooler. I was reading of a person who used a old a/c core and welded a aluminum box, airtight, around it.

Not that I am running that terrific level of boost that I am in need but if the time comes I believe the water intercooler would be the way to go. Unless, I want to route it around the car like the route the coolant goes.

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87 Fiero GT (Rotrex Supercharger)
86 Fiero SE (My first Car)
97 Grand Prix GTP
WWW.ANGELFIRE.COM/PA5/DAVIDFIERO

No need to go with a homemade intercooler when there are so many doner cars available with good ones. Check the junkyards for Turbo SAAB's a lot of people really seem to like these intercoolers.

I would think that routing it all the way to the front of the car and back would limit your boost.

Another drawback is you run a greater risk of bursting an intercooler line.

I would think a water cooler would be more efficient.

Unless you have some kind of body kit on there where you could run the intercooler on the right side of the car inside a big cowl?

[This message has been edited by Dago (edited 09-16-2002).]

why put the intercooler in the front, just put it in the trunk and get one of those indy scoops up top to supply the air to it. Not to sure on any details, but there aer no rules saying the intercooler must go upfront

quote Originally posted by Dago: No need to go with a homemade intercooler when there are so many doner cars available with good ones. Check the junkyards for Turbo SAAB's a lot of people really seem to like these intercoolers. I would think that routing it all the way to the front of the car and back would limit your boost. Another drawback is you run a greater risk of bursting an intercooler line. I would think a water cooler would be more efficient. Unless you have some kind of body kit on there where you could run the intercooler on the right side of the car inside a big cowl? [This message has been edited by Dago (edited 09-16-2002).]

you can get a direct fit intercooler from a Saab?

quote Originally posted by IROC: you can get a direct fit intercooler from a Saab?

Considering that there is no Turbo Fiero from the factory there would be no such thing as a "direct fit" anyway.

I am just recommending a cost saving option. You can get an intercooler from a junked Saab WAY cheaper than buying an aftermarket intercooler.

If you mount the intercooler on the right in front of the wheelwell under the battery and get a sidescoop

There are a half dozen or so good aftermarket cores. If you want to do a custom water/air IC, I'd recommend getting one that has low internal flow resistance, and small size, since the water system will make up for these factors with higher heat transfer coefficient. A DSM core would probably fit the bill pretty well.

Here's a good site that compares the flow resistances of many common stock cores...

http://home.earthlink.net/~turbogus2/intercoolers.html

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Red Devil Racing

Picture of an intercooler installed in a turbo 3100. It is a saab 900 intercooler. The side intake feeds air to the underside, a fan beneath it blows air through and it vents out the top of the drivers side engine vent.

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85 F-40 Replica (unfinished)
88 GT 5-speed
02 Millennium Yellow C5

[This message has been edited by godalex (edited 10-06-2002).]

quote Originally posted by godalex: One other thing about the AC core idea... too small! The intercooler needs to cool the air with out causing a major restriction. The tubing inside the AC core would be way too restrictive and cause boost pressures to dramtically increase. (IMO)

Seems you need to talk to the engineers at Thrasher to explain to them that this is not a good idea. http://www.thrashercharged.com/L67_htm/new_cooler.shtm

quote Originally posted by skitime: Seems you need to talk to the engineers at Thrasher to explain to them that this is not a good idea. http://www.thrashercharged.com/L67_htm/new_cooler.shtm

I would if it was air to air, but their system is water cooled, and housed for a supercharger. I made the assumption this was for a turbo, not a supercharger. In the case of the 3800 SC and other similar setups, then that would work. I c now that rotrex is using an SC. ( I didn't catch that the first time) So, my bad.

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85 F-40 Replica (unfinished)
88 GT 5-speed
02 Millennium Yellow C5

My SC is similar to a turbo. The reason I started this thread is because I discovered a link where a guy made a intercooler with a a/c core.

It's not so much the heated engine compartment in the Fiero, but the lack of air flow that is a problem. For me I noticed over the summer how hot the blow off air was from my charger. Just too much heat, and for me, not enough ventilation.

Let us back up and look at what an intercooler does. An intercoooler is used for two reasons to remove heat from an intake air charge produced by a turbo or a supercharger and to help prevent detonation. It in itself provides no added power gain but allows an engine to utilize higher levels of boost efficiently thereby allowing the engine to produce more power. Intercoolers are usually used on boosted applications where the boost exceeds around 9 psi. At 10 psi and above heat can be detrimental to the operation and life of an engine. I've given though to installing an intercooler and using 12 psi boost but there is really no cool place in the tight Fiero engine compartment to locate one. Yes you could fit an intercooler there but given the high under deck temperatures,I really question the efficiency and value of one.
My solution is to build an alcohol/water based injection system with an adjustable pressure switch, power relay, a small oil burner nozzle and a 12V high pressure sprayer pump sold by Northern Haudraulics. I am gathering up all of the parts right now and expect good results when using it. I would believe that this system will really cool things down.

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87GT 3.4 Turbo Best 0-60 5.2 seconds
http://turbofiero.fierojoe.com/turbo.htm

I agree. I was talking with this guy at the track and what he suggested was a kind of one-shot intercooler utilizing some ice water mounted in the trunk.

I dont like the intercooler mounted where the vents are simply because of all the heat that radiates upward from the engine. I would be more worried I was heating rather than cooling air.

Anyone mount

This bears a question. Would I gain any performance with the following setup?

use an AC unit conected to the compressor to cool the air on a engine without a turbo or supercharger? How cold cold you get it and how much would that efect the air density?

quote Originally posted by RotrexFiero: I agree. I was talking with this guy at the track and what he suggested was a kind of one-shot intercooler utilizing some ice water mounted in the trunk. I dont like the intercooler mounted where the vents are simply because of all the heat that radiates upward from the engine. I would be more worried I was heating rather than cooling air. Anyone mount

What you don't see in the pic is the fan and ducting under the intercooler. The fan (small radiator fan)runs all the time when the engine is running so it is pulling cold air from the side air intake and forcing it through and out the vent. I doubt that very much engine heat enters into the equation, but then it is not my car and I don't know. (If it were I would isolate it though so heat wouldnt be a problem) I think the idea is practical and brilliant, a great balance of all the variables, access to a place to vent air, location close to an air source, proximity to the intake. I posted it only because I though it could be of use to someone.

The thing I don't like about water injection or alcohol injection: If others drive the vehicle. In that case, the other person may not refill the reservoir, and could blow the motor.

In my experience idiot proof is always good, and an intercooler doesn't require the regular service. One of the main rules of engineering is to perceive potential problems and address them ahead of time.

Food for thought.

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85 F-40 Replica (unfinished)
88 GT 5-speed
02 Millennium Yellow C5

[This message has been edited by godalex (edited 10-07-2002).]

quote Originally posted by Earl: This bears a question. Would I gain any performance with the following setup? use an AC unit conected to the compressor to cool the air on a engine without a turbo or supercharger? How cold cold you get it and how much would that efect the air density?

Somebody asks this every few months. It's a common idea. So, if it's such a common idea, why doesn't anyone do it? Simple - it won't work. Don't believe me? Try it and see. If you make it work, you'll be rich. Good luck.

Not trying to be mean, but it something that you'd see every backyard mechanic doing, and kit for sale at AutoZone with big Type R labels on it if it actually worked. Ok, you'd probably see the Type R kits even if it didn't work, but you get my point.

Just for giggles: (And remember it is 5 AM so I hope I did the math right)

Assuming that engine efficiency increases 1.75% (air density) per 10 degrees of temperature drop, and that at 100% efficency the engine produces 200 HP.
We will also assume ambient air temp of 100 degrees F. (and not calculate for engine temp raising this)

Air passing over the coil in a car running A/C produces 44 degrees as the air temp exiting the vent. We asume a box is built around a coil and intake air is routed through this box.(understand that as air volume increases thermal transfer decreases, but we will assume a large box, that contains the cooling coil, and that it works like a plenum so the air slows as it enters the larger space of the plenum, and of course, all things being equal, which they are not in the real world)

100* F - 44* F = 56* difference 56*/10 = 5.6 1.75% x 5.6 = 9.8%

9.8% more air density or more power.

200HP + 9.8% = 219.6 HP Almost 20 HP. Now being that underdrive pulleys can free close to 8-10 Hp, I'd have to assume that the AC compressor while working is using significantly more HP than that. So you see, in the end, there is little gain, and probably a deficit by the time many more variables are calculated. (If someone can come up with what an A/C compressor uses we would know for sure)

The reason intercooling works so well is that you are dealing with air temperatures sometimes as high as 350*F. (higher boost levels) If one brings this tempearature with in 20-40 degrees of ambient, then you have reduction of 230-210*F or 40-37% more dense air charge and correspondingly more power.

Ok, time for sleep.

[This message has been edited by godalex (edited 10-07-2002).]

Also, most AC compressors cut off under full throttle because of the power drain on the engine, and the fact that they can't withstand high rpm operation. If you run a compressor at high rpm too much, you'll ruin it.

Here is another sorce of a commercial intercooler for the 3800SC.
http://www.zzperformance.com/zzp/products/intercooler.htm

quote Originally posted by godalex: What you don't see in the pic is the fan and ducting under the intercooler. The fan (small radiator fan)runs all the time when the engine is running so it is pulling cold air from the side air intake and forcing it through and out the vent. I doubt that very much engine heat enters into the equation, but then it is not my car and I don't know. (If it were I would isolate it though so heat wouldnt be a problem) I think the idea is practical and brilliant, a great balance of all the variables, access to a place to vent air, location close to an air source, proximity to the intake. I posted it only because I though it could be of use to someone. The thing I don't like about water injection or alcohol injection: If others drive the vehicle. In that case, the other person may not refill the reservoir, and could blow the motor. In my experience idiot proof is always good, and an intercooler doesn't require the regular service. One of the main rules of engineering is to perceive potential problems and address them ahead of time. Food for thought.

I totally agree with you on that air to air design. I thank you for posting it. I will have to consider it.

I have studied the water/achohol system and one nice feature about it is that with the modern computer controled system if knock is detected due to lack of water injection the computer will retard the motor and attempt to prevent damage.

[This message has been edited by skitime (edited 10-07-2002).]

As mentioned I have a centrifugal SC mounted where the Fiero A/C unit was mounted. On the SC I mounted a temp. sender unit which allows me to monitor the SC temperatures from the cab. Of course the SC generates some of it own heat, but you would be surprised how little air moves through that engine compartment. For a engine it is fine, but for an intercooler I dont believe there is sufficient air flow.

A fan is good, but a scoop would be better. For my charger I have tried a fan, but a well designed scoop, even on steamy hot days, is able channel more, cooler air. Plus the cooling is proportional to your speed, so the faster you go the more air.

I figured that side scoops would be good, and I reasoned that it would be simpler to fabricate an IC rather the retro fit some other IC in the Fiero.

Quote: "I have studied the water/achohol system and one nice feature about it is that with the modern computer controled system if knock is detected due to lack of water injection the computer will retard the motor and attempt to prevent damage."

Good point and one I did not consider. That would make me feel better about going that route.

A 7727 computer can be programed for TGP code (turbo grand prix) or modified code and has the input for the knock sensor.