With the factory clutch tossed Ben had no choice but to locate an aftermarket unit with enough vise pressure to transfer the horsepower. OS Giken, a well-known entity in Japan, was the weapon of choice due to its twin-disc clutch set-up complete with flywheel. On most high-horsepower applications clutch failures occur within the drive straps. The drive straps is what connects the pressure plate cover to the pressure ring. This is the part that comes in contact with the clutch disc. On the OS Giken pressure ring there are no band clamps, just a floater plate in between the twin-discs. Although the floater plate is loud the payback is a clutch with enough clamping force to transfer all the horsepower his Supra can put out.
Since the OS Giken clutch was a few weeks on back order from GReddy, its authorized distributor in the States, the next upgrade was to enhance the suspension on the Supra. Ben stated, "At full boost, the rear would squat excessively causing the rear tires to camber out and lose traction at 60 mph." To solve the problem Ben applied a set of Eibach Pro Kit springs mounted on a set of KYB AGX shocks. Helping out the traction department are four Bridgestone Potenza S-02 Pole Position tires mounted on the stock 17-inch rims. In the rear are 255/40-17s and the front is home to 235/45-17s. Stiffening up the suspension points are GReddy front and rear strut tower bars.
A few weeks after the suspension upgrades the clutch was in and the Toyota was ready to hit the dyno again. After a few 17-psi low-boost passes the Supra pumped out 518 rear-wheel horsepower. Then it was time to address high-boost tuning. The Blitz boost controller had its last preset dialed into 22 psi of boost and after its first untuned high-boost run the Supra spit out 570 horsepower. Once Rod Millen was done fiddling with the VPC and GCC the car's last pull was able to break the 600 horsepower mark netting 618.6 horsepower with 532.8 lbs-ft of torque. This is more horses than Ben anticipated!
Fuel tuning is critical on...
Fuel tuning is critical on any type of engine so this Supra uses a HKS VPC and GCC for tuning the injector pulse width as well a Paxton fuel pump and HKS regulator to handle fuel pressure stability.
The dream of a true street performer isn't always based on buying the expensive car. In Ben Treynor's case, his dream came true in the vision of a stock-looking Toyota Supra built to out perform any "Supercar" at anytime. Considering the internals of the engine are all OE parts holding up against 600-plus horsepower is enough to give this car the respect it deserves-Keep up the good work Ben!