Speed Ventures was hosting another auto-x which provided the perfect venue to test the tires as you get a ton of runs and you don’t have to work the course. Also, my co-worker DWood was in town and he’s a very very fast driver. It’s always good to get a different perspective, so the both of us ragged on the car at the auto-x.
My biggest impression, aside from the increased grip level, was how easy the tires were to drive at the limit. The NT01s have a relatively rounded shoulder compared to many other tires and I think this contributes to their progressiveness at the limit. My reduction of toe-in at the rear shifted the balance back to neutral and made the car very easy to drive with the throttle. DWood’s comment was that during steady state cornering, it was very easy to adjust the attitude of the car; a lift of the throttle would cause the rear to rotate out and getting back on the throttle would bring the rear back in. The progressive nature of the NT01s made it very easy to drive the car at the limit.
When I was driving the car, if I felt I was going a bit wide of the apex, a quick lift would rotate the rear around in a very easily controlled manner. I could use a light tap of the brakes to get the rear to rotate even more when I wanted to, but it was so progressive that I had no fear of spinning. I really can’t communicate how easy it was to shift the car between under and oversteer with just the throttle; I’ve never driven anything else that can adjust line mid-corner as easily as Project S2000 as it is currently setup. I had to relearn to drive the car a bit as getting on the power would just plant the rear, grip, and go. I had no fear of power oversteer which the car had done before. The car is just stupid easy to drive with the NT01s. Just for fun, I could pitch the car a bit into the corner with a little lift throttle causing the rear to rotate and then get back on the gas to plant the rear and accelerate forward. Speaking of accelerating, the shorter sidewall of the 235/40 NT01 effectively gives the car shorter gearing which improved acceleration as measured by the butt dyno.
|These pictures show the shoulder wear on the left front and rear tires after the auto-x. I have not touched the tire pressures since they were initially set at 32psi cold. The camber is still -2.0 on the front and -2.8 on the rear. It appears the tires are getting pretty well utilized with the current camber settings and tire pressures.|
So how did Project S2000 do at the auto-x? Dan got down to a 35.4xx. There was a Civic EK hatch that also ran a 35.4xx. I ran a 37.0xx. There was one Miata I saw in the 36’s. The Hotchkis Suspension FR-S ran a 36.2x on 235/40/17 Falken Azenis RT-615K (the car also had an intake and exhaust). A 370z ran a 37.x. A RX-7 FD, LS swap, and on 235/275 RS-3s ran a 37.2x. A gutted, caged, 300+ hp turbo Yaris on R888s was in the 37s. I think there was a STI hatch in the 37s. From there, it was a pretty steep drop. I remember seeing a Porsche Cayman S along with a 911 running 39s. An Evo X running a 40. And from there, a whole lot of cars were in the 42+ range with some clocking in closer to 45 or slower. Dan and I left early around 1:30 (after showing up a bit after 9am and getting around 30 runs between the two of us), so maybe some managed to turn a faster time. But, I have to say, not too bad for driving there, taking some crap out of the trunk, running, putting said crap back in the trunk, and then driving home. I didn’t even bother with the tire pressures, though in full disclosure, I did adjust my suspension rebound settings to my ‘track’ setup the day before. However, with the softer ride of the NT01s, I’m just going to leave the rebound settings where they are.
|Another look at the left side front and rear tires.|