1990 Sunbird LE to 1.8L turbo project - General Forum

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1990 Sunbird LE to 1.8L turbo project
Thursday, June 14, 2012 5:55 PM

Hey guys!! I could use your advice with this project. I know that I'll need a bleed valve setup in the vacuum line going to the MAP sensor/computer, so that the ECM never reads more than 7-9 pounds of boost. I'LL NEED A BOOST SENSOR. I also know that I need to cut and threat the actuator rod and put a nut on it, since boost isn't adjustable from the factory. If you have anything in a file as far as the procedure you guys have used that you could send me, that would be great. As far as electronics,

What I have:

1) 1.8L LT3 engine from a 1987 Skyhawk $595, $130 to ship it.(good find, Eh? Only 59,000 miles! One of those cars where the turbo suffered catastrophic failure and they parked the car)

2) 7749 ECM for that engine. Not sure of number haven't looked at it since I bought it in 2006, but I made sure the numbers were right.

3) Turbo $150 bucks, which in 2006, was a good deal, most were selling for $400-$450.

4) 1990 Sunbird LE convertible-paid $2200 One owner 113,000 miles, but the engine leaked oil like a seive, she boiled the oil and pegged the oil temp guage. Still ran, man, those LT3's were tough engines. The coolant system was a new style, and I don't think she was used to checking a resevoir for coolant level.

5) A new GT four core radiator, correct for the factory turbo set-up, which means, I'm going to run oil and coolant through the turbo, and the T-3 Garret I have allows for both :-) That being said I will build an intercooled Sunbird convertible eventually that is modified I'm also looking for extra turbos.

6) Summit Racing oil cooler, w/electric fan. I'll set this up on a relay and thermostat, with a manual switch for back-up.

7) I'm going to run a 3" exhaust better hp at high rpms, and the 1.8 is capable of revving abit higher than the 2.0 thanx to shorter stroke. This may produce a scavenging effect, but more torque/hp at high end that way.

What's your take on using the air conditioning condenser as an transmission oil cooler? Should work if channels are big enough. Don't know since it is a vapor/gaseous appliction. It should work with the right compression fittings on the end of the tubes.

Other Stuff I need? Suggestions? Detonation controls from gt? bypass speed limiter? I don't think I'll need to change fuel pump will I with stock injectors?
I'm ordering new head bolts and head gasket. Should I run the GM turbo gasket, or try the ISUZU gasket? I'm also going to install a remote spin on/off tranny filter set-up.

Re: 1990 Sunbird LE to 1.8L turbo project
Friday, June 22, 2012 3:55 PM
I would not advise a 1.8l. The 1.8 and 2.0 are like the least reliable engines ever made. I had one rebuilt 3 times now and its at 38,000 miles. I am finally ripping it out as we speak and putting a 3400/3500 hybrid in. Those engines are notorious for spinning bearings and have other major problems. They never last . Especially with a turbo. Expect a lot of down time. Just trying to save you a lot of head aches. I would love to have kept mine since the car is show room condition with a white interior, white top, white paint but the engines are just crap. If yours last consider yourself very very very lucky. Hope everything works out for you.

On the inside my car looks like a fighter jet.
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