968 tire pressures for Hoosier R6s?
06-03-2010, 11:15 PM
#1
Bannana Shine
Rennlist Member
Rennlist Member
Thread Starter
Join Date: Jul 2009
Location: Rochester Hills, MI
Posts: 21,055
Likes: 0
Received 334 Likes
on
219 Posts
968 tire pressures for Hoosier R6s?
Going to my first autocross on Sunday. I've only ever driven road courses (Sebring, Moroso, and Homestead) so besides not knowing what I'm doing, I ALSO have the wrong tires (R6s instead of A6s). How bad is that going to be?
Anyway, what cold tire pressures would you recommend? I usually pay attention to hot pressures, but that doesn't seem practical for an autocross, is it?
Anyway, what cold tire pressures would you recommend? I usually pay attention to hot pressures, but that doesn't seem practical for an autocross, is it?
06-03-2010, 11:54 PM
#2
TIRE PRESSuRE RECOmmENdATIONS FOR COmPETITION
Traditionally, Hoosier tires have often required higher pressures than other brands. This has changed with the A6/R6.
Roadrace/track applications
VEhICLE SIzE RECOmmENdEd hOT PRESSuRE COLd PRESSuRE
1800-2200 LBS. 30-33+ 22-27
2200-2600 LBS. 31-34+ 23-28
2600-3000 LBS. 33-37+ 23-28
OVER 3000 LBS. 34-39+ 23-29
+Higher pressures will improve the performance capability but will require a more sensitive feel to take advantage of the
increase.
One characteristic of the tires is the tendency to “skate” initially (when inflation pressures are correct). It is important to resist lowering the
pressure to attempt to eliminate this feeling. Dropping the pressure too far may improve the “feel” of the tire however it will also lower the
performance and increase the wear rate.
Banked Oval / Road Courses
On these type of course configurations, the loaded side tires should be elevated four (4) psi (hot) above the normal road course pressure
recommendations.
Autocross applications
For autocross applications, your starting pressure for the first run should be within 1-2 psi of the recommended hot pressures shown above.
After the first run and each subsequent run, keep resetting the pressures back to your target hot pressures before taking the next run. This
way your tires are at the proper pressure during the bulk of every run you take.
The above chart is a general recommendation which is intended for a standard configuration vehicle (i.e. front engine, rear wheel drive).
Factors which can radically affect your pressure set up would include front wheel drive, independent rear suspension, rear engine, McPherson
vs. control arm front suspension.
Traditionally, Hoosier tires have often required higher pressures than other brands. This has changed with the A6/R6.
Roadrace/track applications
VEhICLE SIzE RECOmmENdEd hOT PRESSuRE COLd PRESSuRE
1800-2200 LBS. 30-33+ 22-27
2200-2600 LBS. 31-34+ 23-28
2600-3000 LBS. 33-37+ 23-28
OVER 3000 LBS. 34-39+ 23-29
+Higher pressures will improve the performance capability but will require a more sensitive feel to take advantage of the
increase.
One characteristic of the tires is the tendency to “skate” initially (when inflation pressures are correct). It is important to resist lowering the
pressure to attempt to eliminate this feeling. Dropping the pressure too far may improve the “feel” of the tire however it will also lower the
performance and increase the wear rate.
Banked Oval / Road Courses
On these type of course configurations, the loaded side tires should be elevated four (4) psi (hot) above the normal road course pressure
recommendations.
Autocross applications
For autocross applications, your starting pressure for the first run should be within 1-2 psi of the recommended hot pressures shown above.
After the first run and each subsequent run, keep resetting the pressures back to your target hot pressures before taking the next run. This
way your tires are at the proper pressure during the bulk of every run you take.
The above chart is a general recommendation which is intended for a standard configuration vehicle (i.e. front engine, rear wheel drive).
Factors which can radically affect your pressure set up would include front wheel drive, independent rear suspension, rear engine, McPherson
vs. control arm front suspension.
06-04-2010, 07:58 AM
#4
Rennlist Member
It is extreemly important to bleed your tires down after each run.
R6s are really not all that bad for autocross. A lot depends on course design and track temp. After burning up 11 sets of A6s over the last two years I decided to switch to R6s for longer life. So far so good. I am managing to hold my division and still even get an FTD once in a while. When I compare my times against other drivers that I know, the difference is maybe 1-2 seconds slower on a 70 second course. Exception was 2 weeks ago when the course was 83 seconds on a hot day. A driver that I am usually head to head with ran out of tire before he could finish a run. Course was just too tight and his tires overheated on every run. He was spraying them too. I was not spraying, but had to bleed after every run. I got him by 2 seconds.
R6s are really not all that bad for autocross. A lot depends on course design and track temp. After burning up 11 sets of A6s over the last two years I decided to switch to R6s for longer life. So far so good. I am managing to hold my division and still even get an FTD once in a while. When I compare my times against other drivers that I know, the difference is maybe 1-2 seconds slower on a 70 second course. Exception was 2 weeks ago when the course was 83 seconds on a hot day. A driver that I am usually head to head with ran out of tire before he could finish a run. Course was just too tight and his tires overheated on every run. He was spraying them too. I was not spraying, but had to bleed after every run. I got him by 2 seconds.
06-04-2010, 06:14 PM
#5
Bannana Shine
Rennlist Member
Rennlist Member
Thread Starter
Join Date: Jul 2009
Location: Rochester Hills, MI
Posts: 21,055
Likes: 0
Received 334 Likes
on
219 Posts
Thanks!
I don't know the length of the course, but this is Florida in the summer...Homestead is forecast to hit 92 degrees on Sunday, I might actually be at an advantage here
I don't know the length of the course, but this is Florida in the summer...Homestead is forecast to hit 92 degrees on Sunday, I might actually be at an advantage here
06-04-2010, 09:04 PM
#7
Instructor
JDS968, also the homestead go kart track is usually between 40-55 seconds depending on the set up, also join us next weekend the 13th at Bank Atlantic Center pre-register at cluregistration.net, PCA Gold Coast Region.
Ernie
Ernie
Trending Topics
06-05-2010, 04:15 AM
#8
Bannana Shine
Rennlist Member
Rennlist Member
Thread Starter
Join Date: Jul 2009
Location: Rochester Hills, MI
Posts: 21,055
Likes: 0
Received 334 Likes
on
219 Posts
Originally Posted by ernie944
also join us next weekend the 13th at Bank Atlantic Center pre-register at cluregistration.net, PCA Gold Coast Region.
06-06-2010, 10:15 PM
#10
Bannana Shine
Rennlist Member
Rennlist Member
Thread Starter
Join Date: Jul 2009
Location: Rochester Hills, MI
Posts: 21,055
Likes: 0
Received 334 Likes
on
219 Posts
You were right, it was the go-kart track.
Ran the R6s at 37 psi all around, aired them down as necessary. I don't know whether A6s would have worked better, but I seem to have had a lot more grip than everybody else. I did a run with somebody else's 135i and the difference was huge.
Ran the R6s at 37 psi all around, aired them down as necessary. I don't know whether A6s would have worked better, but I seem to have had a lot more grip than everybody else. I did a run with somebody else's 135i and the difference was huge.
