DAVfoto

I've searched but not much available about whether guys do this or not. I've seen a couple of videos and I'm considering doing this next weekend with the North NJ PCA region. My tires are not performance summer, just the performance all seasons so I may lose a little bit of traction. But I think this would be fun and I've done a couple of crosses before and some small track time.

Any thoughts as to what air pressures to run? Right now at 38 front 44 rear. Should I keep or go up a little bit to prevent sidewall roll.

I plan to get a Go Pro suction mount so I will show the vid to you all when I go.

slavie

I did a few runs just to get a feel for the car. I have a 957 GTS with Tiptronic, and there was never a moment I wished more for a manual. It's a heavy car, great for what it is but not exactly nimble for autox. But hey, go for it - your Cayenne won't even break a sweat.

Keep in mind that most clubs have regs against SUVs and other "top heavy vehicles" on track/autox, so you'd want to be triple sure that the club you run with will let you. Though I think PCA is more lenient towards Cayenne/Macan as those are now like 50% of new Porsches and they want to include these as much as they can to keep the club going. SCCA and NASA are a no go as far as I know, unless something changed recently.

DAVfoto

Yea I figure DE and Autocross shouldn't be too big of an issue but club racing would be no go for an SUV.

sclemmons

Just do it. And post pictures here. Autocross is a benign activity even for Cayennes and you will have a blast.

dbv1

My local club won't let me autocross the Cayenne, fine for snowcross or rallycross (lower speed).

I'm not sure about the pressures for Cayennes but conventional wisdom says drop the pressures for the event (for bigger contact patch). Experiment.

I would keep the prescribed differential between front/rear because of the transfer case. Your pressures are too low when the steering becomes lazy, or if you feel the sidewall sway when you chuck the car around. Some tires have indicators (triangles) at the edge of the tread that mark the spot past which the tire shouldn't come in contact with the road. Folks use chalk to mark the sidewall to see which part of the tire is actually making contact with the road so they don't drop the pressure too low.

Bear in mind that autocross is harsh on the tire. If you lock the tires up, they'll flat spot and start howling afterwards. The constant heat cycling or running them at low pressures doesn't help either. The car shouldn't have problems with any of it though.

Don't forget to turn off traction control once you're confident you can manage the GTS for max speed and fun.

deilenberger

Perhaps it's different in Canada, but in the US - those triangles are used to tell you where the wear indicators are in the treads. They're required by NHTSA. Might be worth checking that out..

dbv1

Hey Don, check out the paragraph titled "Visual Pressure Check" here:

http://www.trackdayguru.com/tyre-management.html

Also:

https://www.nison-tyres.com/replace_tyre.php

Maybe it's a common misconception?

DAVfoto

Thanks for the tips! I did email them and no response yet if my Cayenne is fine.

Any way to have passengers? I have a friend that might come. He has a Nissan Maxima so not sure if they allow non Porsches at the event either but he could possibly drive his.

Joe Weinstein

Passengers is a separate issue, per club. Some say that only event participants can be passengers. Some say that if there is more than one person in the car, at least one has to be an instructor for the club. My local PCA club has had Cayennes run, and they have an official class designation. Once as an instructor I drove a stock '93 Dodge Caravan around the course with 6 newbie drivers as passengers. One of them thought the van was special and hotted-up and offered to buy it because that run was faster than some newbies in their Caymans etc.

As to tire pressures, I'd go higher than stock initially, to protect the sidewall from deep wear if the tires roll over too much. Worry about stick later. Chalk the sides of the tire and adjust pressure till the chalk is only worn off about 1/4" up around onto the sidewall.

Eskimo1

That's what I was always told too, but it's been a while since I tracked a car.

dbv1

Good advice.

DAVfoto

So chalk the entire sidewall or just the sides near the contact patch? Thanks for the advice, will do!!

Joe Weinstein

Just up an inch or two up the sidewall from the outside edge of the tire. If any or all of is is scrubbed off more than the 1/4" closest to the tire tread, add more pressure. If none of it is scrubbed off, drop 2-3 psi and do your next run. Repeat till only the 1/4" goes away.

Then you will start to consider camber. The Cayenne (to my second-hand knowledge) does not offer much adjustment for camber, but once you know you need it, get what you can get.

deilenberger

How about checking out a more authoritative source: https://www.goodyear.eu/uk_en/truck/...ing-your-tyre/ - look at #9. BTW - the Nison link shows basically the same thing, but they don't explain that it's in line with the in-the-tread treadwear indicators. It makes it easy to locate them and then run your thumb across the tire to see how much tread is left.

Or https://www.nzta.govt.nz/vehicles/ch...-basics/tyres/

The trackday-guru is about what I'd expect by someone calling themselves a "guru"..

A few images, out of MANY found with a simple Google image search:


That's from the NZ website - a government website, whadda they know anyway..



Bridgestone Tire owners manual


Michelin has to do something a bit different..


VW Gulf manual


What can I say - I'm sure someone told the guru that, and thusly it became internet fact..

Joe Weinstein

I will also be autocrossing my car some time this year, depending on when any of the series I am competing in are either in the bag or irretrievably in the toilet.

What wheels and tires are you running? I can recommend tires, once you get hooked.