Real Life Amature Test: Street vs Track Tires

[North Coast Cab]

Ok, it wasn't exactly scientific or anything, but today I ran 1/2 day with my street tires and 1/2 day with my track tires and I have a few notes.

Nelson Ledges Road Course Fun Day
For those that haven't been there it is a fairly short, but very fast track with questionable sections of pavement and undulating sections of pavement. Sort of looks like something you'd build in your backyard. About 15 total cars from a GT1 SCCA Camero to a Boxter with dealer plates. Also, it's a track where you really really don't want to go off as it's elevated and muddy and has little open safe run-off area. Finally, last fall I went off, 2 wheels, the rear came around, I 360'd across the track, through the mud, and bounced off the tire barrier. Therefor, I'm afraid of the track and tend to start out very conservatively.

Street Tires - Yoko AVS Sports
Started out fairly calm and worked into the groove. As speed increased and rythem became better the car really started to push and slide, but felt under control. I felt very fast yet enjoyed the go-cart style of driving as I worked to stay on line.
As the morning went on I think my desire to push harder started to cause problems. The rear decided it wanted to be in front several times, though I managed to save it every time. The front seemed to start to push terribly at times and it became difficult to stay on line. Then during the last session of the morning I found myslef in an area called Oaktree which is about 120d left hand turn where the track is slightly banked on the inside. As I pushed the car down to the inside and feathered the throttle all four wheels slid and pushed out to the center of the track in a very strange motion. I never lifted and did my best arm excercise to get through the turn, 60-75MPH, and then things got back on track. I decided it was time for lunch.

As I ate lunch I couldn't decide what to do. Keep the street tires and regress my driving style or change to the track tires and see how things feel.

Track Tires - Kuhmo V700's 80% tread
So I swapped the wheels and busted onto the track. Immediately the steering wheel shuffle and go-cart effects were gone. There was little or no push and the rear end was happy in the back. A couple laps in I realized my RPM's and speed were far surpassing the morning sessions. As I continued to push, kind of a bad habit I have formed, striking changes emerged. When the tires started to go they didn't walk they ran. Mistakes seemed to be much more magnified and the potential for extracuricular activites seemed to lurch into the picture. I again began to think about what was going on and how I wanted to proceed. So I spectated for a while and then went back out and drove 7/10th for a while feeling everything as I went and then slowly increased my enthusiasm. Things seemed better and faster and confidence was building.

So what does this mean? Well, I have to mention again that my experience is somewhat limited and that I am not a race car driver, instructor or expert.

Street tires are slower.
Street tires are more forgiving and controllable.
Street tires provide great ifeedback.
Street tires should be mandatory for all novice drivers.

R-compound tires are faster.
R-compound tires take time to heat-up and stick.
R-compound tire go away after a while.
R-compound tires provide less feedback and are less controllable.

For me, I will continure to carry both sets and at times use them. Uncomfortable situations or new tracks are great applications for the street tires. High comfort levels and experienced tracks are great avenues for R-compound tires.

John

[Kurt B]

Cool. Nice write up. Appreciate it. I wonder about the differences between these two and figured unless you were in the rain, street tires would always be a step behind. Interesting that the racing tires become harder to control. Maybe it's because the bulk of the tire is on the same plane, and when you break friction, you don't have any surface area to help stop the slide.

[lateapex911]

Now, get a set of Hoosiers, and do the same test.....I bet you end up writing the same list, but adding a new level...Hoosiers are faster, Hoosiers are REALLY greasy until warm, Hoosiers provide MUCH less feedback....and so on. But don't heat cycle them more than 7 times, or you'll be driving kuhmo equivilents! LOL

[89911]

Nice write up. It is all true. The only think I can ad is that with time, you will get the feel, predictability, and limits of track tires. They will do many of the same things that street tire do, just in very small room for error. The only way to get there is to keep running them and adjust. Going back to street tires will just remind you of how much you are giving up and losing in time around the track. When I run on street tires, I feel like I need to enter a drifting contest.