We re going to nurburgring

[ek1]

My personal opinion about the Kumho's is they are by far the stickiest and fastest production tire ever put on a street legal car.

- Yes, for about 10-12 miles of relatively mild track driving, then they fall off. Andy's note about Kumhos losing a lot of grip on the last third of a lap mirrors exactly what people that rack their ACR-Es with Kumho's have experienced. The length of Nurburgring is roughly 12.9 miles, so 2/3 of that is roughly 8.6 miles. So in a hands of a very fast professional race driver, Kumhos grip for about 8.6 miles and in hands of people who are slower, they grip for about 10-12 miles, but some people corded their Kumhps in a few track sessions or about the same as 2/3 of a Nurburging lap.

If I had any reservations about the tires it would be the front size. I think the issue is that the sidewall is too short (being 25 series) for the amount of energy and downforce the car can create, especially on rough tracks with bumps, etc. The shorter sidewall probably gives much better steering feel for such a wide front tire but the trade off is no give, curb pinching and the possibility of breaking the bead if the pressures a just a little too low. A smaller diameter wheel with a 30 series version might solve a lot of the front tire issues.
Again, just my opinion.

I think this is 100% correct and also mirrors my observations. I am currently using taller P295/30ZR-19 Hoosiers on the front of my car now and although I give up a bit (about 10%) of front end grip, one set of tires already lasted 3 track days on short and medium length tracks and will last at least one more day.

Like Andy said....more car than tire. Very frustrating to everyone who contributed to this effort, including myself, but I am pretty sure everyone who tracks their ACR-Es already knew that. I definitely did.