For 1989, Pontiac added a couple of engines to the GP lineup. As a midyear introduction, a stroked 3.1-liter version of the 2.8 V6 was implemented, but coupled only to an automatic. The larger engine developed 140 hp at 4800 rpm, with 180 lbs.-ft. of torque at 3600.
      Also available only with an automatic transmission was the Grand Prix Turbo, which actually was not just an engine option, but a limited-production car that could truly be called the first high-performance Grand Prix since the demise of the 455 SJs. It differed from lesser models in quite a few areas.
      The engine was developed by ASC/ McLaren for use exclusively on this car. While the block and bottom end were the same as the normally aspirated versions, they were "hardened selected castings" with more rigid quality-control standards than normal. The turbocharger was the Garrett T25 model. The water-cooled turbo blew into an air-to-air intercooler on its way to the multi-point fuel-injection system.
      The modifications were good for a very respectable 205 hp at 5200 rpm, with 225 lbs.-ft. of torque at 2400. Maximum torque was actually governed by the computer to avoid overloading the beefed-up automatic transaxle. ABS was standard a GP first.
      The body received revised front and rear fascia panels, as well as larger side skirts to accommodate the 245/50ZR-16 Goodyear Eagle Gatorback radials, which were mounted on gold cross-lace 16x8-inch wheels.
      The exterior revisions definitely gave the GP Turbo an aggressive and distinctive look, which it could back up. Zero-to-60 times were in the low 7-second range, with quarter-mile times in the mid-15s at around 90 mph.


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