Gains from tires?

[Grintch]

Plus remember almost everything BUT super sticky tires (R compounds or slicks) is legal in CAM-C. So you might be giving a lot away in addition to your tires.

When the spec tire changed on the SRF from the bias ply Goodyears to Hoosier R7s. I saw a 5 second improvement on most road courses (~100 sec lap). So yeah, tires matter a lot.

Sponsored

 

[NightmareMoon]

Plus remember almost everything BUT super sticky tires (R compounds or slicks) is legal in CAM-C. So you might be giving a lot away in addition to your tires.

CAMC is 200TW, so R-compound slicks are not allowed. Are you thinking ESP?

 

[TeeLew]

CAMC is 200TW, so R-compound slicks are not allowed. Are you thinking ESP?

He's saying everything (engine, suspension, etc) is legal in the class *except* R-compound tires.

 

[Steve68Cougar]

I just got back from my first autocross outing with 200tw tires. Major difference to say the least. We had a test and tune yesterday and competition today. A friend of mine had his GT350 out there on the same size tires I had (305/30-19). He's got worn out RE71Rs and I've got new RT660s. The last time we were on the same course (about 2 weeks ago), I ran a 69.x second best and he ran a 62.x second best. This week he had a 55.995 and I had a 57.644. There are always other variables, but this is an example of how much just switching tires can make. We discussed it a bit, and realistically the approximately 5 second gain I made was not all due to the treadwear rating of the tires (340 vs 200). There was definitely an increase in confidence on my part because of how much better the car felt with the new tires. One other part of it is that I went from a 275 cross section Continental Sport to a 305 cross section on the RT660s. That in itself makes a significant amount of difference. So, the truth probably lies somewhere between 2-4 seconds on a 60 second course when it's tire for tire and size for size. It's probably closer to 2 in most cases. I could probably be convinced that it's less than that with a professional driver. That being said, my PAX score last outing was 78th out of 116. This week was 46th out of 106.

 

[Gearz]

Hi Steve, it was great seeing you again last weekend. I should have also mentioned that I my RE71s were going off when we ran at Topeka, then I put around 20 runs on them at the Chicago 3-day event before heading back to Lincoln. They still have grip, but what I'm finding is they just don't have as much peak grip capability, the +1.5G levels that happen sometimes like a tight turn after a slalom or if I get behind the course. It felt like your new RT660s were much more tolerant of those kind of inputs when I drove your car. That is what I meant by giving the driver more confidence. I'm really looking forward to getting a fresh set on my car for MiDivs, hopefully I won't be sliding around as much. Sometime I'll have to make some runs on my street tires in the dry and then swap out to the stickies to get a decent comparison.

 

[Steve68Cougar]

Sometime I'll have to make some runs on my street tires in the dry and then swap out to the stickies to get a decent comparison.

It was great to see you again, too. Thanks for the clarification. The bit I quoted would definitely be something I'd be interested to see. I'm sure your consistency (experience and skill level) would be a more realistic comparison than what I did. The number of variables within my comparison was pretty high. Also, thanks for the advice and information this past weekend. The car is obviously still faster than I am, but hopefully I can continue to make improvements and be more competitive.

 

[K4fxd]

I switched to less grippy tires and was able to learn what the car feels like on the edge at a slower speed and I think this was the best move I have made in tracking a car yet.

This times 1000

Sponsored