Tire compound/size experimentation

**2/3rdsCobra** · September 13, 2019, 09:34 AM

Proof, OK - https://www.facebook.com/omegamotors...type=3&theater TTD for the last event I attended.

**timcking** · October 27, 2019, 10:25 AM

Originally Posted by argonaut

I'm using A7s - 225 front, 245 rears. With 14 heat cycles on them I did a 1:35:5 at Summit Point Shenandoah. Thats smoking fast. The best I can do with with R1s is 1:40s. So much for the theory that A7s only last 8-10 cycles.

Argonaut, what tire pressures are you running? How about camber? I completely overlooked you're using the same size A7 tires that I am. I haven't had much of an opportunity to experiment with mine. I do know my car is very well balanced with this size tires and the settings I've been using. And the 245 rears don't require any speedometer correction ... a factor if you drive on the street.

**argonaut** · October 28, 2019, 05:45 AM

In the summer, in > 80 degree conditions I ran 18 psi front and rear. Now that its cool in the north east I'm running 20. My car was aligned by TMI and set up to their SRA race specs but adjusted slightly for the bigger than stock tires. I don't know what the exact camber, etc. is.

**timcking** · November 27, 2019, 01:29 PM

What pressures and camber settings have you found to work best? Thanks.

**texevora** · November 23, 2020, 04:14 PM

Nankang AR-1s are now available in 275/35R15 (in addition to 205/50R15), which is the rear tire size I've landed on (I've been running 205/50 fronts and 275/35 rears in Hoosier A7s).

Curious if anybody has experience with them and can provide feedback on them relative to A7s and R7s? Seriously considering picking up a set to see if i can bring down my tire cost per session and still keep most of the lap time performance.

**Phoenix Atom** · December 26, 2020, 09:32 PM

I can't help with the Nankangs, but I'm finding that with A7s, 225/245 are as quick or quicker than 245/275. Cheaper, too.

**texevora** · December 27, 2020, 02:29 PM

Interesting... I found little difference between 205/225 fronts, and a noticeable difference in rear grip going from 245 to 275. Guess it all depends on driving style. <shrug>

I have a set of A7s and R7s that i'm going to do a back to back test on when it warms up. I'll probably buy a set of Nankangs around then as well just to try them out.