VetteDrmr

Well, I'm taking the plunge from Toyo RA-1/Kumho V700s and stepping into the Hoosier/V710 world of tires. Following my autox nickname of "The king of cheap", I've got several sets of used tires, and am going to be mixing and matching different versions of Hoosiers. Once I kill these off I'll be buying scrubs that are hopefully the same vintage.

My first set mounted has a 305/18 R3S04s on the rear, 275/17 A3S05s on front.

FOR AUTOCROSS ONLY, what kind of tire pressures should I be running, both starting off cold and what should I be aiming for hot?

TIA, and have a good one,
Mike

JiminVirginia

I'll be interested in the replies, as people run all different kinds of pressures on Hoosiers. Last weekend, some friends were running low 20s, while I was at 32-33 lbs hot.

I would not use the R series for autox, though, as your rears won't be heating up as well as your fronts, where you're running the A series.

VetteDrmr

Jim,

Thanks for the reply. Don't forget my Motto: I'm cheap! They won't be best, but I'm hoping they'll be better than my RA-1s (which are 3 years old!). Also, EVERYTHING here in TX is having zero problems heating up!

Have a good one,
Mike

Z06Fix

If I can remember off the top of my head... I'm thinking that the older version hoosiers S04/05's needed to be in the high 30's to low 40's hot.

The A6's need to be high 20's to low 30's hot. I just switched over from the V710's to the A6's and will be trying 28frt 26rear at this weekends autox.

PushinTheLimit

That's the pressure's that I ran at this past weekend at our local autoX and I was happy with how the car felt. It was only my first time ever on R-compounds, so I'm probably not the best to give feedback on them until I get some more runs on them. I'll be using the same pressures again the next time and see how I fare again.

VetteDrmr

Thanks, that's just what I was looking for. I'm guessing about 4 psi rise in temps, so I'll start them cold around 38 and go from there.

Have a good one,
Mike

c4cruiser

I have a set of A3S04's on my 87 and I usually start with 41-42 psi up front and 35-36 at the back. The A-compound tires do heat up quickly and I check the pressures after each run once I get back in grid.

Depending on the course layout, surface temps and how hard I run, I will adjust the pressures as needed. Because the tires tend to heat up quickly, I usually have to drop the fronts a couple psi after each run once they get hot.

Some courses may get laid out in a sort of circular pattern where the majority of the turns are to one direction. I will occasionally see a couple psi difference between the left front and right front tires if there are more turns in one direction than the other.

You can always place a chalk line from the top of the sidewall to the top of the tread to check how a pressure change will affect scrub.