Original owner of a '90 Sunbird GT Turbo here.
The 122 CI 2.0L, inline 4 cylinder, non intercooled turbo motor, was produced from '87 - '90. Known as the LT3.
GM 122 engine - Wikipedia, the free encyclopedia
It was produced in Brazil. It had a hp rating of 165 hp and 175 lb ft tq. It used a Garrett T25 turbo with a .64 A/R T25 internally gated turbine housing. It also featured a water cooled center section for longevity concerns of the period. Boost would vary from 7psi up to 9.5psi depending on ambient conditions. It was an optional motor in the '87 - '89 models and the only option for the '90 Sunbird GT Turbo. In '90, you could also order a sleeper. It was a Sunbird SE with the turbo motor. I'm sure those were quicker as they did not have the ground effects package or the rear spoiler that the GT had. I would guess about 50#s lighter. This motor was also the standard mill in the '87 - '89 Buick Skyhawk T-Type and was an option for the '87 - '89 Pontiac Grand Prix SE. (Other motor being the 2.3L Quad 4 in the SE)
It was rumored, that Lotus had a hand in the development process of this engine when GM gave the 1.8L Turbo an overhaul in '87. Seeing as around that time frame GM purchased Lotus and the Lotus Espirit Turbo at the time, was a 2.2L intercooled turbo 4 cylinder that made serious hp and was also painted red.
Two weeks after getting my Sunbird I took it to the track on it's maiden voyage. I left the track that day with a 15.20 @ 92 mph time slip. There was a magazine article that came out two years prior, where they track tested a '88 Sunbird GT Turbo and did some mod tricks. This consisted of removing the air box assembly and icing down the intake for an hour at the track. I believe they were able to crack into the 15 flat range. Over the next 3 years, I proceeded to upgrade mine, the same way you would a Turbo Buick. Adjustable wastegate actuator for more boost (12psi was the limit before the ECM would shut off the injectors), custom ram air / cold air setup for the turbo and a test pipe. My best ever pass on regular radials (drag radials didn't exist back then) was a 14.26 @ 99 mph. With a horrible 1.90 60ft. I was just about to sink more money into the car in the form of a customer air to liquid intercooler, when a buddy of mine found me a 1 owner '86 T-Type for a steal back in '94. So, hot rodding the Sunbird took the back seat while I hot rodded my first T-Type.
These motors were notorious for developing leaking head gaskets due to several conditions. A loose and or malfunctioning coolant temp sensor would cause the fan not to turn on, which would lead to over heating and then a blown head gasket. (Patrick raises his hand) It's what ultimately happened to mine. The other reason was detonation due to low octane fuel and people just running them into the ground. There are currently two very low mileage GT Turbo convertibles for sale on Auto Trader, that are decently priced for what they are. It's very hard to find a mint low mileage Skyhawk T-Type or Grand Prix SE Turbo, as most people drove them to death.
I still have mine tucked away in my garage, waiting on the motor swap and or converting it to LS motor and RWD. Torch Red, low options and 5 speed.
Sorry to ramble on, but I have a passion for these cars as well. I had alot of fun with mine. My best memory was street race I had against Mr. Fiscus back in '94. He drove a friend of our's bone stock Turqois '93 Mustang Cobra. I got the jump on his and held 1 car length on him the whole race. WOOHOO. Good race.
Thanks for the flash back.
Patrick