Astroman

My last two weekends at Mid Ohio have really hammered the outside edges of my left side tires (stock suspension, limited camber). My question is: Can I replace the left front and left rear tires only??

My tire guy said it may upset the "balance"... that he's only replaced two fronts or two rears at a time (or all 4)... never one of each. The front right tire has tons of life still... It would only be the right rear tire that could possibly upset the "balance," if at all.

Sorry I don't have pictures, the wheels are at the shop.

Thanks a lot.

smlporsche

I think it depends on the difference between the tires.
RA-1's like ALOT of neg camber (I'm running -3.5, -2.6).
If you can't get that much you can flip the tires so that the outside of the tire is now on the inside and extend the life.

JackOlsen

Switch the lefts and rights (and inside and outside shoulders) by dismounting and re-mounting the tires F<->F and R<->R. I wouldn't mix old an new RA1s, even in pairs. The lifespan of that tire sees really significant changes in its handling characteristics.

DGuida

With a front engine you will probably go through front tires first. Run them until you cord one, then buy a new pair of fronts and bring the used front tire that didn't cord to your next event as a spare. Do the same for the backs. This way if you have a problem with a tire at an event you don't shorten you weekend. It's always nice to buy a new set, but putting on a used spare to get you through the weekend is better than going home early. Also, like suggested, watch how they wear, and switch tires as needed. If all four are the same size you can also switch front to back. RA1s are not directional except in the rain

DGuida

sorry, I thought I read you were driving a 944, you backs will probably go first. But it will be the same routine

Astroman

Yeah, that's what I had planned to do. Except, my tire guy says the outside front left is too worn to even use in the inside front right.

My rear tires were wearing faster than my fronts (as expected in a 911) UNTIL Mid Ohio where the horrible understeer I get in the Keyhole and Carousel really destroyed my front left tire...

If the new ones will handle significantly different than the old ones, then I guess I'll bite the bullet and get a new set and use the medium-worn right sided tires as spares like DGuida suggested... Oh well... Thanks.

986

Two weekends and too worn to even flip? Hard to imagine unless your events give you tons of track time per day (say couple hours per day).

You can certainly mix new tires with used. That was how your tires were at Mid-Ohio, (left side bald, right side tons of tread left) and it felt alright, no? If anything getting a new tire will make your front axle "more balanced" (whatever that means...)

Just checking... is your left front really down to the cords? Make sure your don't throw it away just because "it has little tread left". RA-1s get better as they wear down, all the way until they cord.

Cheers,
Toby

M758

IN a DE enviroment run them till you see cords. On my 944 I run the same tire sizes all 4 corners and rotate positions of the tires after each track day to even up the wear. I also run -3.5 and -2.5 camber. You should be rotating at least left/right each track day to even up the wear if you run different sizes front and rear. The "left" & "right" markings are only used for rain. In the dry they can be run backwards without issues.

Veloce Raptor

RA1's get better & better. They are at their best immediately before they cord.

trackjunky

Two points. First, make sure that you are not "over tired". I don't mean sleepy, but what is the width of the tire compared to the rim width. Make sure that you are not rolling over the tire. Second, you are going to need way more camber (as stated above).

I ran a set of RA-1's for 2 years worth of DE's before they wore out. You might also want to take a look at the temps across the face of the tire. I have found that when I run a little higher pressure than I first thought, I had better wear. For example, I used to aim for 38#'s hot, but using my pyrometer has caused me to change that thinking. Just my 2cents.

Astroman

The left tires have not yet corded... but it does appear to be imminent (especially on the outside front). I would just hate for it to cut my next weekend short (or worse, fail tech). I know they perform better and better as they wear... which is exactly why I'm so hesitant to replace 'em... and why this a little frustrating.

Also, my mechanic (who used to race) told me that running directional tires "backwards" was a bad idea because of the construction of the tire. Is this true, too?? I always thought that was considered a "plus" of RA-1s... being able to run 'em both directions (when it's dry).

Veloce Raptor

Your mechanic doesn't know beans about RA1's.

Run them in any direction in the dry. Run they in the direction on the sidewall in the wet ONLY IF THEY ARE FULL TREAD.

M758

Yep my Toyo dealer recommends this exact thing. In fact when buying shaved tires some times I get 3 lefts and 1 right. Even at 4/32 directon does not matter wet or dry.

mark kibort

I think you are right on here. my fastest times of the weekends recently have been on my near bald, RA1s. as many know, i use only the scrubs from SpeedGT, and my "A" set, that i qualify on and race with , are always near .25 seconds slower.
Im sure buying the sugestion that they are best right before they cord!

mk

Chris M.

Is this also true for MPSCs?