AX street tires vs cup tires

[harryrcb]

I was afforded a unique opportunity to test how much difference, if any, cup tires would perform at an AX event compared to street tires. I was asked to help design and setup an AX course for our Sunday event. I ran my street tires on the setup day and after a couple of laps did a consistent 46.5 second run. at the event on cup tires I ran a 44.2
A beautiful day at Zepherhills Air Port with a good turn out of participants. I believe we had 40 drivers and a variety of cars. Unfortunately for me, I had one of the top dogs run in my class who even took first overall with a 42.2 (beating our national champion) but I took second in class and in the top 5 overall. the total scores did not get posted yet but it was fun anyway so here is one of my faster runs and one practice run where I did not do so good.

[Grant Lenahan]

thanks for posting - very nice run(s). I'm surprised the tires didnt result in a bigger difference. when you say street vs CUP do you mean michelin PS cups or do you mean R compound slicks.....?

Grant

[harryrcb]

Originally Posted by Grant Lenahan

thanks for posting - very nice run(s). I'm surprised the tires didnt result in a bigger difference. when you say street vs CUP do you mean michelin PS cups or do you mean R compound slicks.....?

Grant

Yes they are Micheling PS cups, the reason the times didn't get too much faster is the cup tires never have a chance to warm up. My best time was the 3rd run with about 2 min wait between runs. I know at Sebring they don't realy stick until the 3rd or 4th lap.

[Tim in N FL]

Harry,
This looks like GREAT fun. I plan to bring my 911 and ///M5 out at some future event. Kudos on the decision to post both your best run and one in which you spun. It is fun to push the limits of both your car and your skill in a safe environment like auto-x.
Best,
Tim

p.s.,
The exhaust note on your '04 Boxster S sounds marvelous. Is that an aftermarket exhaust unit?

[Sterling Doc]

Nice & smooth - well done!

[Pete R]

great video. Where was the camera mounted. I've haven't seen a view like that with out a windshield or hood in the pic. btw were those grasshoppers trying to get out of your way?

[Wayne 962]

It sounds like your times may be really limited by your gear ratios. I think I can hear you reaching the top and staying there because a break / downshift is coming. I've driven both the manual and Tiptronic Boxster, and here is where the Tip shines - it really does respond very quickly, and gives you more power when you needed it - at the end of the rpm range when you'd normally be concerned about downshifting. I have the same issues in my 1972 911 RS clone...

-Wayne