tyre pressures

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Jun 23, 2003 | 06:23 PM

dove

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From: suffolk,england

tyre pressures

Could someone please tell me what tyre pressures I should have for 17 inch turbo cup alloys size,front;245/40/17 rear 265/40/17.

Paul

C2 cab wide low & loud

Jun 23, 2003 | 06:30 PM

joey bagadonuts

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From: Highland Park, IL

2.5 bars or 36 psi all around should do it.

That'll be $100 please.

Jun 23, 2003 | 06:31 PM

GMS

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From: Seattle WA USA

Tire pressure for stock cup 17" wheels is 2.5bar (cold) front and rear. As you have wider you may need to experiment a bit.

Jun 23, 2003 | 06:38 PM

dove

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From: suffolk,england

Thanks for the advice guys,$100 very reasonable.

Paul

C2 cab wide low & loud.

Jun 23, 2003 | 07:29 PM

joey bagadonuts

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From: Highland Park, IL

<blockquote>quote:<hr />Originally posted by dove:
$100 very reasonable<hr /></blockquote><img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />

Jun 24, 2003 | 12:32 AM

BGLeduc

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From: Albuquerque, New Mexico, USA

<blockquote>quote:<hr />Thanks for the advice guys,$100 very reasonable.<hr /></blockquote>That could only come from someone who has acclimated to paying Porsche prices for things!

BTW Mr. Doughnuts, I have swapped shocks and springs, and now have Bilsteins and H&R's (not the turbos). Nicely lowered (finally) and lots of negative camber on tap (well, at least more than before).

I have had to adjust my previous autocross pressures on the Victoracers, and am currently running 35/38. I still think 30/40 was the way to go with a stock suspension, but with the new pieces and the resulting alignment change, I have had to tweak things a bit to get the roll over where it needed to be.

BGL

Jun 24, 2003 | 10:53 AM

joey bagadonuts

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From: Highland Park, IL

<blockquote>quote:<hr />Originally posted by BGLeduc:
That could only come from someone who has acclimated to paying Porsche prices for things!<hr /></blockquote><img border="0" alt="[hiha]" title="" src="graemlins/roflmao.gif" /> <img border="0" alt="[hiha]" title="" src="graemlins/roflmao.gif" /> <img border="0" alt="[hiha]" title="" src="graemlins/roflmao.gif" />

Thanks for the update, BL. I'm FINALLY getting some camber this week (I told my wrench to max it out) and also having the 75K service performed. The car's been in the shop for over a week so it should cost a grand or two. Sounds reasonable. <img border="0" title="" alt="[Wink]" src="wink.gif" />

I'm running the Michelin Pilot Sport Cups, now, and will need to start all over with the chalk/shoe polish tests for auto-x. As you probably heard, they take a while to warm up so I'll probably start at 32f/34r which is close to their optimal hot pressures.

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Jun 24, 2003 | 07:46 PM

joey bagadonuts

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From: Highland Park, IL

Thanks, Irish!

So that's ~36 psi cold. I'll give it a try.
<img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />

Jun 24, 2003 | 07:59 PM

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BGLeduc

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From: Albuquerque, New Mexico, USA

<blockquote>quote:<hr />I'm running the Michelin Pilot Sport Cups, now, and will need to start all over with the chalk/shoe polish tests for auto-x. As you probably heard, they take a while to warm up so I'll probably start at 32f/34r which is close to their optimal hot pressures.<hr /></blockquote>Those tires must have a pretty stiff side wall to be happy at those pressures when hot.

They do make an intersesting contrast to what some of autocross buds run in their Hoosiers (auto-x compund, and not on P Cars). Those things don't seem happy unless they are at at least 40 PSI cold. And if you start out too low and roll over onto the side wall, it trashes them.

I only ran them one season when I had the Integra Type R, and I seem to recall front pressures up around 50 PSI.

What's the word on wear on the Cups? Looks like with my Victoracers, I will be getting about 2 seasons out of a pair of fronts and 1 season out of the rears.

Sticky is good, but at some point $$$$ enters the equation; thats why I have not tried the Hoosiers on the P Car. More expensive than the Kumhos, and they don't last as long.

BGL

Jun 24, 2003 | 10:00 PM

#11

joey bagadonuts

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From: Highland Park, IL

Oops, it looks like I miscalculated. 2 bars is ~29 psi. Yes, that might be a little low since I ran the Cups at around 34-35 psi HOT at the track with good results. I used a pyrometer to gauge my pressures. Since there's no opportunity to warm up your tires at autocross, Irish, I need to be a bit higher BUT 2 bars is approximately the same COLD number I used at the track.

BL, the word on the Cups is that they should last at least twice as long as the Kumho's and their performance is just a hair shy of the Hoosier track compounds. So even though they're a bit pricey, $920 for 225's and 255's, I should break even in the worst case.

I can tell you that after three track days (10 heat cycles) they look pretty darn good and have the original tread grooves on all four, whereas the Victo's looked like race slicks after just one day on the track. The compound seems significantly harder and they don't get greasy towards the end of a session which the Victo's tended to.

I wore my Victo's down to the cords after five track days (16 heat cycles) but I believe I could've gotten a lot more usage had my setup included some camber. Doing the Carousel at Road America for four days at around 80 mph just ate up the shoulders.

Surprisingly, the Cup sidewalls don't seem as hard as the Victo's. Since I drive them to and from the track, I've noticed that the tramlining is not as pronounced nor is the steering as heavy as with the Kumho's. They feel just like great street tires ... that is, until I push them hard in the corners.

No complaints.