Didn't read the complete thread but by the way your crossover cracked it looks like the turbo needs to be braced better. Heres a pic of the GN headers I made. If we don't support the turbo they will crack or the turbo will sage to the drivers side. You can see two braces the main brace goes back to the end of the head.

quote Originally posted by Billybo455: why don't you just buy some pipe, bends, and a flange. bring them to me with your stock setup and come back the next weekend and have a new tig welded setup that's a little better then what you have :P

I Really appreciate that offer and I may take you up on that if the following doesn't work.

Here are the pics: I think it looks a lot stronger and cleaner.

Where is the wastegate going to be now?

It's still there at the bottom of the y pipe--it dumps near the axle to ambient air

Which turbo are you using? Do you have a boost gauge? If so, how much boost are you making?

It's a large t4 --boost is adjustable under the dash--max boost is 18lbs.

That is sweet. 18lbs, wow. What are you running for ECM programming? How about injector size?

Although I cannot vouch for the accuracy of the following----It was written by a previous owner of this car:

My Fiero IMSA - The Story
According to what I was told, this IMSA started its life in 1985 as a racing car for IMSA GTU events. After the original SD4 blew up, the second owner who bought the car with the blown engine did not want to replace the (very) expensive SD4. He decided to go with a turbocharged and intercooled GM v6 instead. Although the work was done in order for the second owner to race this car in uphill events, it sat in a garage for 8 years or so, and was only driven occasionally (he put 5,000 miles in 8 years). After the second owner decided he would never race it anyways, and unable to find a private to buy it for the kind of money he was asking, he decided to put it up for an collector auction. I ended up buying it before it reached the auction room as a good friend of mine find out about it and told me it was for sell. The car has around $45,000 worth of parts and labor in it. It had 31K miles when I purchased it, new 3.1L engine out bored to 3.2L and built for racing with lower cylinder compression (to compensate boost from turbo) and performance parts.
The car also had the original air scoop (the one which goes above the top of the cabin), but the second owner did not like the looks of it and threw it away !!!. I was actively looking to purchase the original scoop and couldn't find any. I ended up ordering a different kind. The scoop's function is to further help the air-to-liquid intercooler to cool down the intake temperature. Another piece I'm missing is the lower front spoiler, which was broken on a speed bump and was also thrown away. I am activerly looking to order. Some good transformations the previous owner did to the car was to add A/C and put a brand new Fiero interior in it with power everything.... Car is like nothing other in the street, looks sharp and drives even sharper !
As I mentioned before, the car was tuned for uphill racing and the turbo was outputting 18 psi of boost. For the sake of drivability and reliability, I lowered the boost (w/ boost controller from inside the car, located under the dash) in order to be able to run the thing on simple 93 gas (about 5-6 psi now). The car has still plenty of power, it's a blast to drive and holds the road like a train on tracks (was supposed to get 1.16 lateral Gs with slicks tires)... I bought a G-Tech and will run some numbers in the near future. Keep in touch !




The Specs:
Street Legal 1985 3.2L Turbocharged/Liquid-Air Intercooled IMSA Fiero
Max Boost of 18 psi (race fuel required)
Dynotested at 335 Rear Wheel HP
245/50R16 at the rear (16"x9.5")
205/55R15 in the front (15"x7")
4 speed transaxle (3.65 Final Gear Ratio)
Quarter Mile in 12.8 seconds @ 112 mph.
1/8 mile in 8.80 seconds at 86.2 mph (reaction time of +.005)
0-60mph comes in 4.90 sec
The Goodies
Garrett TO4B Turbocharger with HKS boost controller.
Custom Liquid/Air Intercooler/Heat Exchanger.
Magnaflow FreeFlow exhaust
Front/Rear Adjustable KONI shock absorbers.
Polyurethane bushings all around.
Front Performance Sway Bar.
Rear Performance Sway Bar.
Performance Brakes.
Boyd Coddington Wheels.
Roll-cage.
Fire Extinguisher.
Racing seat.
Racing harness.
Window net.


Engine's Specs:
3.2L turbocharged, blueprinted, race-tuned GM V6 engine (original 3.1L)
Custom air-liquid heat exchanger (intercooler)
Max Boost of 18 PSI (race fuel required)
Redline @ 6,800 RPM
Unknown engine HP. Vehicle Dynotested at 335 RWHP
The Goodies
Garrett TO4B Turbocharger with HKS boost controller.
Custom air/water intercooler.
K&N Filtercharger
Magnaflow Free Flow exhaust
Polyurethane bushings for engine mounts

If you ever get it to the drag strip you might throw a video our way. That sounds like a fun car.

Stupid question:

Do you have to use the steel gasket between the turbo and the exhaust flange or can you use high temp rtv ????

The highest temp RTV I've run across is like 600*. That manifold can get 1300*.

i always use metal gaskets on my starion.

quote Originally posted by jeffndebrus: Stupid question: Do you have to use the steel gasket between the turbo and the exhaust flange or can you use high temp rtv ????

It's best to use no gasket at all. If the mounting flanges are pretty beefy (like 1/2" thick), check them for flatness. If they are perfect, use no gasket at all. If they are warped, get them flat or use a steel gasket.

7 1/2hrs today to reinstall the crossover, bolt the turbo to the flange, and reconnect the plumbing.
If this fails again I will not fix it in the car. I will drop the cradle----and most likely if I drop the cradle I would switch to another power plant all together. It would be Northstar or 3800sc, with 3800sc being my best bet for great gas mileage and performance in the same package.
But for now, we shall see how the 3.2 turbo does. I still have to fabricate a support bracket for the turbo.