In a demonstration of what two modified road cars can do, we see the role of modifications play; where minor tweaks and comprehensive builds differ. In the red corner, a Corvette Grand Sport. The C6 is a formidable car from the factory, and put a talented driver like Steven Kronemberger in the seat, and it’s quite a handy track car.
Kronemberger is a discerning driver, and has made a few minor modifications to sharpen the Corvette. Among the short list of upgrades are Hawk Performance DTC 70 pads, Nitto NT01 tires, a supportive Recaro Pole Position seat, and MCS 2-way coilovers. Since last time we featured this monster, the MCS coilovers have made the 3,350-pound car much more manageable, both over curbs and under power. It may only be lightly modified, but with 440 horsepower and a strong innate balance, it’s a force to be reckoned with.
However, the Corvette has its work cut out. The car is struggles to catch is a race car with license plates, so it’s excusable. Shane Besharaty’s Subaru STI is driven occasionally on the street, but with a cage, a stripped interior, and upgrades in all the relevant areas, the Subaru is a stone’s throw from a dedicated, trailed, track scalpel. In fact, it’s set up for the Street Class in Global Time Attack.
The motor is made for competition. The Cosworth shortblock, though using stock heads, camshafts, and compression, has the right supporting modifications to make it outgun most cars. A responsive Garrett GT3076R turbocharger, a reverse intake manifold, 1700cc injectors, and even a flex fuel kit allow the 2.5-liter motor to make 480 horsepower at the wheels in usable fashion. That tractable motor, when combined with plenty of traction from the Cusco differentials, makes it indomitable out of hairpins and slow-speed corners.
Weighing just 3,000 pounds, the lithe Subaru has an obvious advantage in slower corners and quick direction changes. Much of that has to do with its lightweight Enkei RPF1 wheels, JRZ RS Pro coilovers, Hyperco springs, Whiteline adjustable lateral links, and grippy NT01 tires measuring 9.5″ across. These additions, as well as some aggressive camber settings, help turn-in and mid-corner speed. Braking is improved from Brembo GTS 355mm big brakes and Motul 660 fluid, and power-down is never a problem in hairpins. The more technical the corner, the quicker the Subaru is.
At higher speeds, the Subaru’s power advantage seems to be trumped by the Corvette’s natural balance. The Corvette has a demonstrable advantage is through the long, fast corners like Riverside (1:34). While Besharaty’s Subaru begins to show the shortcomings of its four-wheel drive in this corner, where long loading causes the driven fronts to slide slightly, the Corvette’s natural balance and willingness to rotate helps it claw back some ground. In fact, a worrying snap of oversteer by the Subaru at the end of the corner—the fastest at Buttonwillow—is enough to give lesser drivers a real fright.
However, that lack of regular traction prevents Kronemberger’s from putting the power down cleanly through short, quick corners like Sweeper (2:03). Note how responsive the Subaru’s engine is in this slow bend; Besharaty rockets away with great traction and stretches the largest gap he enjoys at any one location over the entire lap.
Some credit has to be paid to Kronemberger and his obvious level of commitment. Despite being on a reconnaissance lap, he drifts the car over Phil Hill (1:46) while the better-damped Subaru stays composed over the crest. This sort of assertive driving is what gives Kronemberger another coupe car lengths in pursuit of the Subaru.
That wheelspinning gusto is the sort of old-school driving ability which makes a big difference in this relatively soft and powerful production car—and the kind of driving that is truly exhilarating and not just accurate. He truly has to muscle his Corvette to keep up with a much faster car, but gusto and some high-speed rotation are enough to close the gap to the time attack Subaru. Not bad for a fairly stock Chevrolet, eh?