Sticky Feet In 2008, the big sticking point was tires and this year was no exception. In '08 we specified 100-treadwear Nitto NT-01 R-compound tires. Given our other choices, this seemed like the right decision since we wanted the suspensions to work to their full potential and not be hindered by "hard" street tires. Since then, Nitto has introduced its new NT-05 line of tires. These rollers bridge the gap between super sticky pseudo track tires and grip-challenged harder tires. With a treadwear rating of 200 they promised to perform closer to a track tire and last more like their higher treadwear cousins. If Nitto didn't have the needed size to fit a manufacturer's wheels they were allowed to run a comparable tire from another manufacturer. It made the comparison to our baseline '10 Camaro more fair since the car ships from GM on 240 treadwear rollers.
Tale Of The Test The point of this exercise is suspensions, so we once again decided to run four segments to our challenge. The slalom and the skid pad are part of our standard battery of tests. The slalom configuration we use is 420 feet long with cones spaced every 70 feet. Cars enter one end at speed, trip a sensor, negotiate the turns as quickly as possible, and exit the other end tripping another sensor. The time through the course is calculated and this yields an average speed in mph. If any cones are hit then the run doesn't count.
The 200-foot skid pad is a large circle with a 100-foot radius. The car is piloted around this circle as quickly as possible without the tires loosing adhesion to the tarmac. The best time recorded from running clockwise is averaged with the best time ran in the counter-clockwise direction. That average time is plugged into a formula to give the average "g" number for that car. The key is that it's an average-g rating and not a max-g rating, so it's much harder to come close to the magic number of 1g. The only adjustments we allowed to be made during the day were tire pressure changes and shock adjustments. No swapping of sway bars or other tinkering could occur. This kept our tests even more firmly anchored in the real world. After all, how many average guys swap out springs and sway bars based on the road they will be driving on? "Run what you brung" was the mantra of the day.
The afternoon was set aside for the autocross runs. Each vendor was given a couple of practice laps to get their cars dialed in. Some chose to do it themselves, but most decided to take advantage of our returning guest driver Mary Pozzi. Mary is an 11-time national autocross champion and was able to give the owners valuable tips on what adjustments would help get their cars through the cones quicker. After each entry got their three runs, Mary got five laps in each automobile. By having the same driver pilot each car we were able to take one more variable out of the equation. Mary pounded each car though the autocross as hard as she could and took notes on each car's idiosyncrasies.
Throughout the day Super Chevy Editor Jim Campisano took each vehicle on a real-world driving trip on the public roads around our test venue. Idling in traffic, negotiating potholes and railroad tracks, were all part of the deal. In this way the cars that came with suspensions set to "kill" could be differentiated from rides geared a bit more towards comfort and civility.
The Moment Of Truth Game day started at 6:30 a.m. After all, we had 10 cars that each needed to be put through four separate tests. After swilling down coffee from a box and noshing on some still-warm donuts, we gave all the cars safety inspections and slapped a number on their windshield. The morning would be occupied by the slalom, streetability, and skidpad tests while the autocross would suck up most of the afternoon. Even with the hectic schedule everyone still found time to have fun. And while all those in attendance were technically competitors, they were first and foremost car guys with a common love of muscle cars.