The Scorch Racing S15’s outrageous power, manageable powerband, and wondrous response are largely due to a massive Garrett GTX3584R turbo—with a V-band housing and a single-scroll inlet. To bring that snail up to full-spool, they’ve bored the motor out to a full 2.2 liters. Though most teams use a shot of nitrous to spool the turbocharger, this SR uses it in a unique system—not using it low in the rev range, but instead, delivering a 200-shot at 7,500 rpm, where the snail runs out of steam. This allows the car to run over 9,000 rpm and dominate the straighter sections of Sydney Motorsport Park. Unconventional, but effective—especially since the ECU compensates the wet nitrous system with the appropriate air-fuel ratio at that particular engine speed.
The Motec M150 ECU allows for flat upshifts, and via a Bosch drive-by-wire throttle body, the downshifts are accompanied by a perfect blip. With shifter paddles flanking either side of the steering column, Under Suzuki can keep his hands on the wheel the entire time in the cockpit.
This allows Suzuki to dial in countersteer when necessary, but this car is surprisingly compliant and puts the power down well. Like the MCA Hammerhead’s motor, the boost is lowered in slow-speed corners, and the Motec M150 limits boost on gear and throttle position to provide a progressive powerband to keep wheelspin to a minimum—and a little traction control helps further in this department.
Though the Silvia has never been known for great traction and poise, it’s been shown to be capable when given the right sort of retrofitting to bring it into the twenty-first century.