http://www.g8board.com/08G8/

V8 time
We took a ride in the G8 GT. Let me tell you ..... do not be fooled by the Horsepower rating. This is a serious ride. Stabilitrack was left active and we were driving in a spirited manor. The roads were wet and the stabilitrack kept us moving forward. With the stabilitrack enabled and road conditions less than adequate, we experienced only minor wheel hop. The G8 GT packed with four passengers and the surprising part was that it got up and went like a bat out of hell. Keep in mind - turning off stabilitrack disabled the entire system, you are on your own. I know - it is not a LS3 or even an LS2. So its an L76. It still has 6.0 Liters of power. It does have great potential. Let me explain: you have a 6.0L Aluminum base (same as an LS2); you have an LS3 intake manifold. L98 (Baby LS7) heads - a great upgrade from LS6/LS2 heads. While its rated for 361 HP, if you ran 93 octane in it and the ECM was tuned for it I bet it would be very similar to an LS2. It does have AFM (Active Fuel Management). There is no light or notice when you are in "V4" mode - in fact I could not tell at all. It is rated for an estimated 15 city 24 hwy economy. If you really wanted to take the car to the next level you *could* upgrade to a slightly large camshaft.... assuming you would be able to disable and remove the AFM system and convert the upper cam sprocket to a 3 bolt design suitable for the E38 PCM.
I buy cats, dead or alive...
http://www.ls1.com/forums/showthread...05#post1219705