quote Originally posted by Joseph Upson:

I would never mount an IC like that. I think you are asking for trouble (the real possibility of something hitting and damaging it). Did you have electric fans mounting on this IC that you had hanging on there like that?

Here's how I've set them up in my builds:



This one in particular had 2 electric fans mounted on it (on the topside) and a tall air deflector, the bottom of which originally sat about 1 inch off the ground. This forced the air coming under the car up into the intercooler because there really wasn’t any other way for the bulk of that air to go under it nor around the sides (because the sides of the deflector were relatively close to the tires). However, with the bottom of that deflector only 1" off the ground it did have a tendency to scrape the ground during normal driving so I trimmed an inch off of it to give a little more clearance. The deflector was mounted to its own bar which was mounted to the cradle so even if something hit the deflector, it would not have a chance of damaging the IC core unless it bounced up into the IC. In all the years I’ve run my (smaller) IC under my Fiero I’ve never had anything bounce up and damage the core in it. If I remember correctly, I think I got that air deflector off an 80's GM RWD car.

With a little more modification, an air-to-air IC with a larger core could probably be fitted in the same location. Is it the best location for one on a car? No. The best location would be up in front of the radiator, but there is no room to run charge air piping up to it on a Fiero unless you want to make some serious modifications to the chassis. The second problem is with the radiator and a/c condenser being up there already, it is crowded so there really isn't room for an air-to-air IC; nor a heat exchanger core for a water-to-air system…at least not enough to work as effectively as they can anyway.

Working with any Fiero is always going to be compromise. There isn’t as much room in these cars as most of us would like to be able to do the things we would like to do to them. Sure you can delete the A/C system and give yourself more room but I don’t consider that to be a viable option since I (and many other people) want working A/C. Even if you deleted the A/C, you still have an inherent airflow problem thru the radiator area due to the stock design of the front-end of the Fiero (which you cannot easy change without doing some rather radical body mods).

quote Originally posted by Justinbart: I never get more than a 16* temp rise with my air to water. That is unheard of with an air to air.

I would be curious to know exactly how you took your temperature measurements (what you used to take them and where these sensors were located) and if you also took inlet and outlet pressure readings so you could get an overall efficiency rating of the IC system you were using. Simply saying you only had a "16 deg" temp rise doesn't really tell us much. I do not doubt what you are saying but more data is needed to draw accurate conclusions.

quote Originally posted by darkhorizon: The plastic L36 intake has been proven to be a great performing intake... and pressure tests to well over 100PSI without issue. I have ran a plastic intake on multiple turbo cars for years now without a single issue, and dyno proven power.... I dont see why these wannabees are coming into this thread saying you need to have an aluminum one.

I don't know if I would trust an original factory L36 plastic intake. They like to crack on stock non-boosted engines, and when they do, they can dump coolant into the intake (albeit from EGR operation). Granted, an updated design plastic intake was made available later that was supposed to fix this problem but the chance of finding one in a junkyard is going to be slim and it is difficult to distingush between the two designs just looking at them. I would be concerned about the durability of that plastic when it is heat cycled + sees the wild pressure swings it is going to see in a turbocharged application. Given how many problems GM had with this plastic intake makes me question how DURABLE it will be in the long run when used with a turbo. Besides that, they don't look the greatest. If someone is going to use a FWD N/A intake, I would recommend they at least use the all-aluminum L26 intake which looks better. But the Camaro/Firebird intake looks the best, in my opinion - and it works good too. Bottom line here is you are never going to need to worry about an all-aluminum intake manifold cracking. So which one is best? That's always going to be a subject for debate since nobody wants to spend the time or money to do all the testing that would be required to prove one better than the others for every possible engine operating scenario.

quote Originally posted by Englishrafe: Good input from all of you. However, I'm a couple of months away from buying any of the intake system - so we'll talk plastic, aluminium, left/right facing, air/water, air/air, mounting position etc... once the engine is back on the subframe (cradle). What are your ideas about compression ratio? Bearing in mind that in Europe I can fill my car with 95 or 98 grade fuel, should I consider going to the highest comp ratio pistons available? The 9.5:1 ones. Is this pushing it a bit with iron heads ? What are you running ? 8:1? 8.5:1? 9.5:1? Yes I know we'll come back to the inter-cooler question, but lets just say that there will be good inter-cooling. I do have a little experience with turbo engines having raced a Renault 5 Gordini Turbo in the past. This car was not inter-cooled (draw through carburettor) and in order to boost higher, we used to decompress the engine with a thicker head gasket down to about 7.5:1. However, this made bottom end response rather sluggish. But wow did that thing fly once the engine hit 3500 rpm and the turbo really started to boost! For the Fiero, I would like to avoid burning out my tires in 4th gear at 110km/h because the turbo kicks in super hard and uncontrollably! (I remember Justin's write-up of a similar experience.) I think that keeping a reasonably good atmospheric phase of the motor with higher compression is the way to go. Not exploding my Getrag with shock loading would also come into the equation! Rafe

It depends on what you want to do with your car and what kind of fuel you are going to be running. The stock 3800 SC 8.5:1 static compression ratio seems to work good with the fuels we can get here in the States. You can run a decent amount of boost on 93 octane (our rating) pump gas (with an intercooled turbo setup) and then really crank it up when you dump some 110 octane fuel in. A higher static compression ratio will give your engine better off-boost performance, but this can limit the amount of maximum boost you will be able to run for a given octane of fuel which will ultimately limit the amount of total power your engine can make.

-ryan

[This message has been edited by Darth Fiero (edited 02-24-2012).]

[This message has been edited by Joseph Upson (edited 02-24-2012).]

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quote Originally posted by ckrummy: It's cost more but why not top mount like a rx7 or a Subaru, it's not ideal but it should work better than putting it under the car. you would have to modify your deck lid but it would be sweet. and forgive me it's an mr2 photo

SHUN! :P

I was thinking an efficient way to use an intercooler would be to change the way air flows through the engine compartment. it goes from bottom up, taking out the heat via the decklid vents. Instead of having air come out the vents, pump air into them via side scoops or roof scoops. Also for this to work, you must modify the rear of the car to include air vents to create a suction on your engine compartment. If you design them right, you have constant airflow through the engine compartment, and some cool looks! You however might lose some trunk space. Then you can position the intercooler(s) under the scoops to have ram air into them.

Only downside is, if you do not design the outlet vents right, you overpressure your engine compartment and underside of the rear of the car, producing some lift and also minimalizing airflow inside of the engine compartment, leading to... lots of heat.

[This message has been edited by Racing_Master (edited 02-24-2012).]