PCA Southeast Michigan Region

From the Blog

In The SharkTank – 04/2012

Now I have a pretty reliable 928 GT which cost me a total of $25k.  In hindsight, I could have just as easily purchased a good, clean 928GT without all the deferred maintenance for about $25k, but it wouldn’t have been as much fun.

In the mid 2000’s there was a “tuner” movement afoot in the 928 community.  People were supercharging or turbo charging their 928s with great results.  If you’ve ever driven the 928 or read some of the reviews from back in the day, you see a common theme emerge – that 928 always seemed a little underpowered.  A bolt-on power-adder that brings it up to 500 or 600 hp is just what the doctor ordered!

There are two basic kits available for the 928 (S4 and later).  One is a centrifugal supercharger and the other is a twin-screw or roots-type supercharger. After much deliberation, I opted for the latter.  A 1.7 liter positive displacement twin-screw supercharger kit took my sleepy little 928 from about 280hp at the wheels to over 440hp!  Talk about waking a car up.

Of course with this much added power, I’ve had to upgrade the clutch, suspension, wheels, brakes and a few other bits here and there.  About four years ago I had a head gasket “event.”  Actually, the head gasket was fine, but the use of the wrong coolant in the motor combined with allowing it to become acrid, resulted in corrosion of the aluminum heads and opening of a fissure between the water jacket and the combustion chamber.  So, we pulled the motor.

Luckily there was no damage.  While the motor was out, I was amazed that the now 130k mile motor had absolutely no signs of wear internally.  The bores were on the low-side of factory and aside from a little bit of cam wear, it was a pretty nice looking engine. I had the heads welded and decked and reinstalled the motor with factory head gaskets.  So far, so good.

I’ve been pushing this car to its design limits and beyond for the past 5 years, and aside from the minor head issue, the car has been relatively problem free. Of course whenever you push a car this far, things are bound to come up, but luckily, not too much for me (knock on wood).  The car is currently sitting on the lift in the garage awaiting new bearings for the driveshaft.  Also planned this winter/spring is a new supercharger that will increase airflow by over 23% and should put overall power at over 500hp at the wheels.  Whodda’ thunk you could take an iconic supercar like the 928 and turn it into a hot rod?