Flying24

Got a couple of HPDE days coming up and I'm wonder how thin can you go on when it comes to tires. I have PS2 RF and I'm right at the inner wear bar on my rears, the rest of the grooves are fine. Also is it wise to mismatch fronts and rears with different tire. I have a set of PSS waiting to go on but my rear are clearly going to wear out first. Enjoy

JeremyGSU

What is your experience level?

Where is the track event?

Personally, I would not go to a track event knowing my tires are just about shot. They will get slick and they will wear out quick IMO.

Also, if you're new to the sport I think you would have a better learning curve running tires that are all the same versus mis-matching. It can be done, yes but it's a lot harder to know the differences in the compounds and know what one can handle versus the other.

Bill Dearborn

Probably can get by fine with that much tread. A lot of guys run with less than that. When on track most of the wear will be on the outside edge of the tire unless there is some sort of alignment issue. The wear bar is at 2/32 and the cords are some distance below the lower rubber surface. We track guys joke about running the tires until you see sparks, however, I would check the tires after each run to see if the rubber from that inner tread groove to the inside tire shoulder starts to show any fabric. If the tire is cambered/toed to the point the inside groove is showing increased wear on the inside groove it is quite possible there is more wear from there to the inside shoulder.

If you take a tread depth gauge with you and check the wear before and during the event you can get a quick handle on how you are doing. I really doubt it will be an issue

I wouldn't mix tires of different construction since they may have different handling characteristics. If you do mix you always want the best handling tire on the rear. For instance I have run R compound tires on the rear and Ultra performance street Michelins on the front with no issue other than increased understeer. However, if the best handling tire is on the front you can get increased oversteer which can be a bitch.

Bill

Bad Karma

If I was at the wear bars and had even wear across the tire I would probably run them. But definitely want to check them after every session (more carefully than normal, because I check them after every run anyway).

It can also depend on conditions. What's the weather looking like? That can influence your decision.
Also where am I running. Much more likely to run them at my local 2 mile track than if I were heading up to Road America.

I actually currently run different front to rear. I have Michelin PS2 and PSS on the car. I will say I feel that they perform very similar to one another. I have had no problem running that mix on the car. I would probably be more worried about running two different manufacturers tires front to rear, but the Michelins seem quite consistent. Also I would never mix tires side to side.

brkntrxn

I run tires until I can see the air between the steel cords.
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Then again, it is a race car and I always have 3-4 sets of wheels and tires with me.

Flying24

I appreciate everyones input;
I'll be at the NCM HPDE event, I'm in the blue group. Brand new track so plenty of grip, did VIR earlier and the surface was awesome. I'm running with 1.5 degrees of neg camber, I think I'll be fine, these Michelins have really held up nicely.

Short-Throw

Despite the track being new, it will be green.

Are you towing your car to the event?

Flying24

O'yes towing otherwise I would change them for sure

froggy47

Will there be tech inspection? Self tech? I would bring those new ones with you in case. Maybe there will be a service there who can mount tires.



When I run with pca I don't know if they would pass a street tire at the wear bars?

63Corvette

I would absolutely agree with Bill, who has lots of experience.
Your tires will "tend" to heat cycle out prior to wearing out (cording) and you will probably find that some of their fastest laps come at (or below) about the "wear bar" level of tread depth

VetteDrmr

Hmm... I thought this was going to be a weight-watcher's type question...

Have a good one,
Mike