The performance bargain that is the Pontiac G8 is very nearly unparalleled in the American market. Eschewing the 'if it ain't broke, don't fix it' maxim for one more adulation-worthy the tuners at APS have seen fit to improve on an already good thing, increasing the output of the Pontiac G8's V8 engine to a Cadillac CTS-V rivaling 557hp.

While the Pontiac is not a match for the Cadillac's smart looks or fine-tuned interior, it is still handsome in its own right, and a great value for money. Toss in APS's inter-cooled twin turbo kit and you have a real screamer that can probably run with GM's top sedan for somewhere around half the price.

With power at 557hp, a rise of 196hp over the stock 6.0L V8's 361hp, it's hard to argue with the results. Torque is equally massive, at 583lb-ft, and is available across a wide portion of the rev range as is the way of the turbo. The Cadillac gets its power from a supercharged 6.2L LSA V8, itself a detuned variant of the 650hp LS9 in the Corvette ZR-1, while Pontiac's own G8 GXP gets 402hp from its naturally-aspirated 6.2L LS3 V8.

The G8's Australian roots show through in the kit, which was actually developed on an Australian-spec vehicle (pictured). The system is engineered to be a simple bolt-on procedure, delivering the massive torque and horsepower gains with a minimum of mechanical fuss.

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