Tire pressure for track days - where should I start? (OEM 19" Pirelli PZeros)

[zcd2.7t]

Yes, I've had my car on the track before, but I was sort of flailing around trying to figure things out and I don't even remember where I started (or ended) as far as tire pressure.

Anyone with experience have any suggestions? (vwong?? Psykotik?) Thanks!

[PsYkHoTiK]

I run 42/40 (front rear) cold (though ~60F ambient temperature - if it is cooler, I pump a little bit more to compensate). Those were with Michelin PS2s.

[resonance]

Autocrossing on stock 19 inch peelers and stock 255 width continental tires, I started out running/experimenting 40 to 43 both front and rear by chalking tires to check for rollover. But I've started noticing increased treadwear in the middle of the tire vs the shoulders where I would expect to see it. I've since dropped down to 38 to 39 and find I have a little bit more grip. I keep resetting to these pressures between runs, a luxury the track guys don't have. YMMV!

[zcd2.7t]

I run 42/40 (front rear) cold (though ~60F ambient temperature - if it is cooler, I pump a little bit more to compensate). Those were with Michelin PS2s.

Thanks - ambient at Grattan Raceway this weekend is supposed to be around 55 degrees, so that's very helpful.

Autocrossing on stock 19 inch peelers and stock 255 width continental tires, I started out running/experimenting 40 to 43 both front and rear by chalking tires to check for rollover. But I've started noticing increased treadwear in the middle of the tire vs the shoulders where I would expect to see it. I've since dropped down to 38 to 39 and find I have a little bit more grip. I keep resetting to these pressures between runs, a luxury the track guys don't have. YMMV!

Thanks. I've typically run my tires at about 37 PSI on the street in an attempt to soften the jolt of harsh impacts somewhat. However, my tires still are much more worn in the centers than the outside edges - the opposite of what I'd have expected. Neither me or my tire guy have any explanation for this as yet.

[PsYkHoTiK]

No worries. Take some vids of the track day!

[vwong]

I run 42/40 (front rear) cold (though ~60F ambient temperature - if it is cooler, I pump a little bit more to compensate). Those were with Michelin PS2s.

+1

For street tires like the Pirelli PZero, Michelin PS2, or Dunlop SportMaxx, I would follow PsYkHoTiK's recommendation.

Since I now run on Yokohama AD08, my target tire pressures are normally 40-42 HOT for fronts, roughly 36 HOT for rears. And for autox, I set them at 48 HOT front/40-42 HOT rear.

[zcd2.7t]

No worries. Take some vids of the track day!

I'll see if I can, but the headrest-post camera mount I used with my previous car doesn't work with the S4's integrated headrests!!

+1

For street tires like the Pirelli PZero, Michelin PS2, or Dunlop SportMaxx, I would follow PsYkHoTiK's recommendation.

Since I now run on Yokohama AD08, my target tire pressures are normally 40-42 HOT for fronts, roughly 36 HOT for rears. And for autox, I set them at 48 HOT front/40-42 HOT rear.

I can't tell you how much I appreciate everyone's input! I prolly would have started with the pressure higher, and that wouldn't have worked well, so this is great.

I'll report back next week with photos and maybe even some video....

[zcd2.7t]

...I'll report back next week with photos and maybe even some video....

Follow up: Tire pressure settings work fine.

BTW - This car is FAST on the track...I passed everybody I ran with all weekend - Cayman Ss, E36/E46M3s, an EVO 9 and of course all of the Audis. The only thing that passed me was a spec Miata driven by a very talented driver. (that same driver also used to pass pretty much everyone while driving a B5 A4 1.8T with a BBK, so yeah....)

Of course, one byproduct of speed is heat in the brakes, and I can report that I discovered the thermal limits of the stock braking system. Pads were fine, it was the Motul RBF 600 that wasn't..... (!!!)

[KayS4]

I have just recently set mines up with 35-36 all around they were at 31-32, I was noticing poor gas mileage at that but the ride is much more harsher at the track I bumped the PSI down I was getting too much wheel spin but then you give up top speed because you increase rolling resistance, you have to play around to find a great balance. I may invest in getting Nitrogen filled up is everyone using regular air? I had my tires taken off put on new rims so it is just reg air I think.

[vwong]

Follow up: Tire pressure settings work fine.

BTW - This car is FAST on the track...I passed everybody I ran with all weekend - Cayman Ss, E36/E46M3s, an EVO 9 and of course all of the Audis. The only thing that passed me was a spec Miata driven by a very talented driver. (that same driver also used to pass pretty much everyone while driving a B5 A4 1.8T with a BBK, so yeah....)

Of course, one byproduct of speed is heat in the brakes, and I can report that I discovered the thermal limits of the stock braking system. Pads were fine, it was the Motul RBF 600 that wasn't..... (!!!)

Glad that the tire pressures worked for you.

What brake pads were you running? Do you have SS lines? Did you bleed the brake fluid before the track day?

[zcd2.7t]

Glad that the tire pressures worked for you.

What brake pads were you running? Do you have SS lines? Did you bleed the brake fluid before the track day?

Carbotech XP-20s, yes and yes.

Given the caliper/rotor temps we measured just after it happened, it wouldn't have mattered what brake fluid I was using.

Next time I hit the track (if there is a next time), the splash guards will be removed and I'll have fitted cooling ducts. I'm convinced that it's the lack of cooling airflow that was the biggest problem (well that and the fact that the car is "all ate up with motor" to quote a once-famous NASCAR driver ;-)

[brooklyn86]

Autocrossing on stock 19 inch peelers and stock 255 width continental tires, I started out running/experimenting 40 to 43 both front and rear by chalking tires to check for rollover. But I've started noticing increased treadwear in the middle of the tire vs the shoulders where I would expect to see it. I've since dropped down to 38 to 39 and find I have a little bit more grip. I keep resetting to these pressures between runs, a luxury the track guys don't have. YMMV!

Doing my my first autocross school in the S4 (done so in my previous car) this Saturday for AudiClub NW (MAMDS 2013).

Wanted to see if for the OEM 19" Continentals, if you or anyone were running 38-39 for both front AND rear with good results? I'm assuming this was the cold temperature?

+1

For street tires like the Pirelli PZero, Michelin PS2, or Dunlop SportMaxx, I would follow PsYkHoTiK's recommendation.

Since I now run on Yokohama AD08, my target tire pressures are normally 40-42 HOT for fronts, roughly 36 HOT for rears. And for autox, I set them at 48 HOT front/40-42 HOT rear.

Or is it more appropriate to set the temperatures when they are hot, as vwong stated? He refers to a different tire brand so not sure how applicable it would be to me.