FirstPorsche

I bought a set of used 16 inch phone dials off of a 1987 944 Turbo. They came with mounted Kumho VictoRacer V700's. I noticed that both rear wheels have "right-side" tires. This means the "direction of rotation" is backwards on the left rear.

I plan to take these to a DE. Need I be worried?

Thanks!

Joe

M758

No problem.
I ran kumhos in both directions just fine. They used to be directional like that, that has since change and I believe all tires have same markings now.

sbelles

Not a problem unless you plan to run in the rain and then only if there is standing water.

RedlineMan

Hey Joe;

Yeh... you'll be OK. For tires with directional tread patterns, there can be gains in water evacuation until they get worn down. For all the others, the directional nature is only in that the tread carcass is overlapped with a beveled, angled end. The tire companies do not really suggest that you run into the leading edge of the angled overlap, but run over it. However, tire engineers torture these things in more horrific ways than we ever will, and they will privately relate that they've never had one come apart being run "backwards."

FirstPorsche

Thank you for the replies.

I feel better now!

Joe

M758

Vitoracer treads are asymetrical, but not directional. So no issues of water. In the early days of the vitoracer the caracass was direcitional like Redline man pointed out. In those case you did need a left and right side tire and so they were put into the tire molds. Of the years Kumho has quit making one of tires (left or right I forget) since they now say their carcasses are NOT directionaly anymore. The just never changed the mold and so the direction is still on them.

There is a little background.

Now I run Toyo RA-1's These are symetrical, but directional in tread alone. That means there is a water evauation pattern the tread and stampeding "Rotation" direction. Even so Toyo says their tirea can be used forward or backward, they just don't advise backwards in the rain.

Most R-compond DE tires can be run forward or backward and most can be fipped on the rim so that the inside is out to get longer tire wear.

Anyone know of R-tire that CAN'T be run backwards in the Dry?
How about tires that can't be flippled the rim? I bet there are few of these however.

mitch236

Is it true that once a tire has been run in one direction it shoudn't be changed? (I know this isn't the question at hand)

Mike Buck

I've been told I can't flip my MPSC. The tread design is very different inside and out. This is a shame because I'm not getting very uniform wear across the tread at the moment. A little tweaking on my alignment should help alleviate this issue though. My primary set still has over 50 heat cycles, so maybe I shouldn't feel so bad

Hoosiers - yes
RA-1's - yes
A032R's - yes
V700 - i think

Mike in Chi

Mike
My shop was instructed to flip my Hoosiers. They flipped all my tires, including the MPSCs.

I was told by a Michie guy that flipped is not optimal, but you can run the car.

I didn't have a problem that weekend.

I don't think I'd intentionally flip them, but there was no adverse effect.

rdstemler

I've had at least two sets of MPSCs that I flipped. Both worked well and I was able to optimize the wear factor. I only did this after checking with DE instructors and other MPSC users. They all said no problem!

I have a set of Dunlop SS on right now. I was told by Sasco that you can flip these but that you need to go to the other wheel ( left front to right front) so you can keep the direction the same. I guess the deal is there is no inside or outside requirement, just directional issues.

The Dunlops were about $150/set less and my times at the Glen are pretty much equal! I'll let you know about wear rates later!

RedlineMan

Hey all;

I'm getting very even wear on my MPSCs from an alignment point of view. Pushing 70 cycles with no demonstrable change in performance that I can really tell. However, the tires on the right wear more on the inside.

I think I need to drive even harder and just get those tires completely OFF the ground! That should even the wear out a bit.

DGaunt

There was a time when the 'spring rate' of the sidewalls on some track tires and racing slicks were different inside vs outside. eg: outside was stiffer. Yokohama A008R was one of them some time ago. I have been out of the loop for a time, but think that this is no longer true due to the increased cost of asymmetrical casing construction and the inability of racers and DE ppl. to get the last lap out of their tire by flipping them. I do suggest you check though, esp. with specialty tires like Hoosier.

Mike Buck

Excellent, another excuse for running at the back of the pack. Tires unoptimally flipped!

But seriously, thanks. I'll ask my tire guy