The video might be more than a decade old, but the sight of the GSC Supra sliding in the hands of Leh Keen still pulls a broad smile across my face. Fed by 21 pounds of boost, this MkIV Supra Turbo delivers 570 horsepower to the rear wheels—which only wear 275-section rear tires. Predictably, the big Toyota likes to move around a little.
Part of the pleasure of this video is witnessing a mildly-tuned Supra driven well beyond its limit on the track. Having lanky Leh, an IMSA ace, 935 tamer, and all-around hooligan, showing just what this unproven car is capable of in the right hands is reassuring for all those who swear by the potential these big cruisers hold. More than just dragsters, the Supra Turbo is a serious weapon on the road course.
In the full trim for the One Lap of America event, this plush street car ran a 1:16.6 at Roebling Road Raceway in Georgia. Not too shabby for something that weighs 3,301 pounds without a driver and runs street tires.
So much of that performance, of course, comes down to the venerable 2JZ-GTE motor. In this instance, a ’98 stock block and heads was modified with upgraded valvesprings, HKS 264 cams, a Titan fuel rail and 850cc injectors, an AEM EMS, HKS DLi, and an Innovative wideband. The turbocharger is a Boost Logic T67, mated to an HKS Type 2 blow-off valve and GT wastegate. Providing that incredible bark are HKS headers, and GSC’s downpipe and midpipe, which route into an HKS Carbon-Ti exhaust.
All the power is sent through a Tilton clutch and then through a stock V160 gearbox, which is known to be quite stout, then onto a TRD LSD.
As for footwork, the Supra enjoys a set of Tein RA coilovers, poly bushings, Titan swaybars, and of course, a set of big brakes to quell the speed. A pair of 14-inch Stoptechs do the brunt of the work in this instance. The only other chassis modification is a Mazworks six-point cage. Put simply, these upgrades aren’t exceptionally rare or exotic, but the car works very well. Such is the potential of the fourth-generation Supra.
To make the Supra deploy nearly six-hundred horsepower without much tire, GSC raised and softened the rear considerably to try and allow for enough compression under throttle. Unfortunately, that had the effect of producing a little entry and mid-corner understeer. Keen can drive around this safety net of understeer, but as soon as the power is deployed, the rears still tend to spin slightly. Fortunately, Keen can use this to neutralize the push and entertain his fans.
However, mild understeer can rapidly shift into snap oversteer thanks to the spiky power delivery. Yet, the car is still stable enough to allow Keen to keep his foot planted and accelerate off the corner with the wheels spinning—so the engine’s power surplus is still capitalized on. Plus, Keen has the hands to catch just about any snap, but nevertheless, this behavior showcases how the Supra is tricky to drive at the limit. It’s a muscle car in the best sense of the term—no doubt about it.
Compared to this older footage, the lead video shows much stronger traction, if at the expense of some understeer.