Tire Experts Please Chime In.

[cashman]

I should have posted this in the Autocross / Racing forum but I am asking the tire experts to check out my Tire review on Post #20 addressing tire roll over.
Thanks in advance.
Dunlop Direzza Star Spec ZII now available

[cstreit]

Looks like a little more camber may be in order... ...but I wouldn't make that call without tire temps because this could also simply be a "feature" of the tire carcass.

[Pete R]

We use Direzza's on our Lemons car. We too experience wear on the edges. Also, for us ,the tire loses grip after 40 psi. Mid to high 30's hot if optimium for us. We often start in the 20's cold. I don't know how much can be applied as your application is different but I would recommend a session or two at a lower pressure and see how it feels

[Cajundaddy]

No expert, just a certified track rat...

Time for more negative camber and less air pressure. -2.5 degrees would make all the difference and still be suitable for the street. 36 psi hot should be ideal for these tires.

[cashman]

Thanks for the responses. I think more neg camber and lower pressure is the solution. I just ordered Cambermax to take care of the back. I may leave the fronts alone at this time.

Next question: Can I increase the Neg Camber in the back at home without screwing everything else up? The car handles incredibly well at the moment. Or, do I need to do the $400 alignment thing again.

[Driven97]

IIRC you need to loosen both the two bolts that hold the trailing arm to the spring plate for sure.

You might not need to loosen the toe adjuster. However, I have not been entirely able to figure out how that camber adjuster works. I think it twists the trailing arm relative to the spring plate, which may or may not effect the toe in the process.

You can always check total toe at home before and after you install the cambermax using the pushpin / plumb bob method, and then check after to see if it changed.

[Dave at Pelican Parts]

In the rear especially, changing the camber will change the toe. And changing the toe will change the camber. (Fortunately, to a lesser extent.) So you cannot do the job without also being able to measure and change the toe angle. Whether that counts as "at home without screwing it up" is up to you; there are many people who do alignments on 911s at home and seem to have reasonable results.

--DD

[RichardNew]

We ran Chump Cars for a couple of years. The tire companies sort of agree on 32 lbs HOT. Just keep playing with your pressures until you get to 32 lbs hot.

You really should by a pyrometer though

Here's an article I did a year back on tires. You can never collect too much information.

Richard Newton
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