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Meet Shrek's biTurbo Corvette

2009-05-21 06:51
Vehicle Specs
Manufacturer GM
Model Corvette Z06
Engine 7.6L, biturbo V8
Power 664kW @ 6 100r/min
Torque 940Nm @ 4 500r/min
Transmission Six-speed manual
Top Speed 354km/h
If Shrek was in the market for a supercar, what would he drive? This is exactly what Karl Geiger asked himself when developing his latest tuning kit.

The Germans are a curious bunch, at times oblivious to the excellence of their homebrewed performance exotics. How else do you explain the survival of Karl Geiger’s tuning shop, located in Munich, which specialises only in American performance cars?

Geiger has a particular penchant for America’s venerable (some would say only) supercar - Chevrolet’s Corvette. Why the latest Z06 Corvette, powered by a 7l V8 engine was in any need of additional tuning is unclear.

As we’ve come to know by now though, German aftermarket tuners provide answers to questions you'll ordinarily never ask.


In Germany green and black is all the rage this summer - allegedly.

If you are going to take a long-nose supercar of the Corvette’s ilk and finish it in a lurid, Shrek-green hue, it had better be plenty fast to offset the mirth of other road users concerning its appearance.

Fortunately Karl Geiger’s technicians are well versed in the art of power extraction, and the Corvette’s swept capacity is stoked to 7.6l thanks to a new crankshaft - which is only the beginning of a plainly ludicrous power extraction exercise.

Stroked and turbocharged

Each cylinder bank’s head is polished and ported, and the centre-V, pushrod actuating camshaft reprofiled. Geiger adds dual turbochargers too, rounding off a pretty comprehensive engine rebuild.

These newfangled goodies boost the Geiger Z06 biTurbo’s output from 375- to 664kW and ushers in a peak rotational force figure of 940Nm.

Both peak outputs are achieved at reasonably low engine speeds, with power Bell curving at 6 100r/min and torque dropping off after 4 500r/min.


GM LS 7 V8 is given a thorough working over, resulting in 664kW and 940Nm, driving through a six-speed manual gearbox. Featherlight clutch action? We think not...

With such monumental output figures begin channelled solely through the rear wheels, Geiger has been forced to bin the standard Z06 drive chain.

A new carbon-fibre drive shaft and toughened up rear differential do their best to cope under the strain of delivering 940Nm to the road, with the 345/25 rear tyres acting as a supplementary clutch.

Even with those generously wide rear tyres, balancing ride and handling quality against traction requirements with 664kW at play is an unenviable task. Geiger’s added new stabiliser bars on both axles, with 18-step rebound adjustable dampers at each wheel corner.

Behind the black OZ light-alloy wheels is a brake system from Stoptech (love the name) configured to be commensurate to the Geiger Z06 biTurbo’s performance.

Boasting 380mm ventilated discs, floating six-piston calipers, at the front and 355mm discs clamped by four-piston callipers at the rear, pure deceleration should be severe.

Geiger’s in-house GT-bodykit for the Z06 biTurbo is a mixed bag.

The louvered black section of the bonnet looks ace, and the centrally grouped, twin dual exhausts ensure the car's rear view is thoroughly menacing, yet the green finish is a little too over the top.

Unless of course, you’re Shrek.


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