Ultimate Street Car Challenge - Skidpad

The skidpad is the dyno of grip. A 200-foot diameter circle looks about as much like a real corner as a dyno roller looks like a road, but as a tool, it's an unbeatable facsimile of the real thing. Skidpad testing was performed exactly as it is for a normal SCC test: The lap time around a 200-foot circle was recorded and converted to lateral acceleration using the power of freshman physics. The fastest two laps in each direction are recorded, so the final score is an average of four laps.

Bringing Hoosiers to a skidpad test is like bringing a small thermonuclear device to a mud wresting match; the fact that seven cars wore Indiana gummies shows in the results. Go ahead and peek at the scores. The only car not to break 1.0g was the only car not running R-compound rubber.

At the top of the heap, as expected, was the Ultima GTR. Knowing more about the car, though, its staggering 1.133g record is actually quite surprising. The skidpad test was, in fact, the first time the car had ever cornered this hard. The Ultima was barely finished in time for the contest and had undergone virtually no testing. From theory to 1.133g in one step is quite impressive, Hoosiers or not. More impressive was how easy it was to drive at the limit, with light, communicative steering and a cornering attitude that responded smoothly and predictably to throttle inputs.

The same couldn't be said of the Viper. With nearly 850 hp on tap, throttle input is strongly discouraged. Jabbing the throttle at 1500 rpm looped the car. The monstrous Viper is clearly designed for going far faster than the 50 mph it sees on the skidpad. In such a tight circle, it felt numb, heavy and prone to understeer. It also tried to overheat repeatedly. Nonetheless, it stuck like crazy, pulling 1.097g.

Matt Andrews was one of the few brave enough to come on non-Hoosier gummies. His selection of Michelin Pilot Sport Cup tires was a calculated one. Hoosiers, he knows, are delicate, and a spin could rip straight to the cords. Rather than risk a DNF, he brought the more durable Michelins. Besides, he had a track day next week, and hoped to use the same tires. Smart guy. The tires were not the problem with his green Supra, but there was a problem. Turning right, the car was brilliantly balanced, but going left, it was all oversteer all the time. It felt like a serious alignment problem, a blown shock, a collapsed spring and a broken control arm all in one. Time was short, so no suspension adjustments were allowed during the skidpad test unless they could be done from inside the car. Andrews' Supra had Tein coil-overs with push-button adjustment, so I was able to adjust the shocks differently for left- and right-hand laps of the skidpad. That, and some very careful left-hand laps resulted in an impressive 1.076g.

James Chen's 350Z had exactly the opposite problem; instead of oversteering on left turns, it understeered turning right. The problem was a loosening wheel bearing, something John Hotchkis said he had seen on other 350Zs.

The Skyline's performance was less than expected, given the extensive track time the car had seen. Like the Viper, though, it was outside its speed range. The turbo was so big, in fact, that we lapped the pad in first gear to get any useful throttle input. Still, it takes a crowd like this to make 1.063g disappointing.

Over All
After driving in circles, the Skyline extended its already dominant lead, while Rich's Supra, hobbled by street tires, tumbled from second to sixth place, with the Viper taking its place. You could only expect more of the same on the track.

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