Speaking of tires, a suspension is only as good as the tires put with it. I chose Continental Conti Sport 2 V-Max to wrap the black forged Fikse Mach V wheels. With this much power and the recent Diffsonline 2.93 differential addition (ec, May '07), it's important to have the best tire possible, with plenty of headroom in the speed rating department. It's the only tire rated for 220 mph. With its asymmetric design, the idea behind the V-Max is not only substantial wet and dry grip but coping with the forces generated at high speeds. It does so with a super-strong structure and a groove pattern that features circumferential cooling grooves and lateral notches for maintaining cooler temperatures.
The car feels like a new model all over again. The TC Kline suspension really is the best of both street and track worlds. At its most forgiving setting, it rides almost as soft as a stock-suspended E36 M3. It's a nice setup for cruising around town or driving in the rain. Crank it down a little more and it still provides a smooth feel on the street, yet gives the confidence to throw the car around familiar turns. It helps the tires provide more grip than I'll ever need in the dry and plenty of grip in the wet. On the softest setting, I've logged a peak 0.95 g around a 270-degree turn at just 60 mph-without breaking sweat. And the stiffer settings leave plenty of room for greater performance with R-compound tires on track days.
Under hard braking with the 14-inch Brembo GT brakes, the tires grip extremely well and the ABS kicks in only if I get a little crazy with the pedal. Considering the braking forces and the horsepower, one would think front- and rear-end squat would be an issue, but it feels perfectly balanced overall.
When I started this project in 2000, the goal was 250 wheel-hp, achieved the following year with a Turner Motorsport cam kit, Evosport pulleys and a Supersprint engine-back exhaust system. In late 2001, I decided to turbocharge the car and the 400 wheel-hp target was with Active Autowerke's stage 2.5 kit, using a 60:1 compressor wheel boosting 15 psi, with some racing fuel in the mix.?
With Evosport's hard-wired installation and custom tuning of an AEM engine management system in 2004, the doors were opened for the current Speed Force Racing/Turbonetics T66 custom turbo system. With a 15-percent mix of 112-octane, the car was getting over 530 wheel-hp in third gear at 18 psi-the maximum load it would see on the dyno. On the street, the load would hold a steady 20 psi-which I would say is easily over 550 wheel-hp.
To call this a super 'street' car, I wanted a 500 wheel-hp pass in fourth gear, using nothing but 92-octane. After some time tuning the ignition maps with the assistance of Evosport's AEM guru, Gary Karamikian, I saw a detuned 506 hp with 440 lb-ft at the wheels in fourth gear (511 wheel-hp with 400 lb-ft in third) at 17 psi with just eight degrees of timing in the upper midrange that ramps up smoothly to a modest 11 degrees up top. Accomplishing this through a not-so-big P-trim turbine wheel in a 0.81 AR housing-plus 8.2:1 compression and stock 95 M3 cams-was very satisfying.