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What tyre pressures do you run?

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Old 01-16-2004 | 05:45 AM
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Default What tyre pressures do you run?

I've been experimenting with different tyre pressures and am favouring lower pressures than those suggested by Porsche. At present I'm running 32psi front and 36psi rear. Probably does nothing for my fuel consumption, but handling feels better.

I'd be interested to hear what you guys run.

Cheers
Old 01-16-2004 | 06:02 AM
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Think you need to mention sizes though. Some of us are still on the old 16s - and I know you're a 17" boy.....
Old 01-16-2004 | 06:18 AM
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D'oh! Sorry, not enough coffee yet.

My tyres are 255/40/ZR/17 at rear and 235/45/ZR/17 at front.

Cheers
Old 01-16-2004 | 07:09 AM
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Phil - I agree about the handling.

I have 225/50 and 255/45 17" and don't feel the car is happy under hard braking unless the rear pressure is above the front. I run the front at 36 and the rears at 40.

I find that the back can feel rather wandery otherwise.
Old 01-16-2004 | 07:17 AM
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17" rims. 205Front, 255Rear 29PSI Front 36PSI Rear.

Kevin
Old 01-16-2004 | 07:41 AM
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After some testing at the track, i found 36f 42r hot worked perfectly on 215/255 16" rims . I think tyre brand makes a slight difference too .
Old 01-16-2004 | 08:15 AM
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17" Cup 1s. 36psi front & rear.

Inteesting that Kevin runs 29/36 and John 36/40

I remember plenty of previous threads on this where someone posted track times and concluded that 36/36 was the best for 17" rims.

I'm sure Porsche did their research when suggesting 36/36 for 17s
Old 01-16-2004 | 09:19 AM
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hmm,
I find that 40 at the rear is way too hard, and compromises the ride over anything less than a perfect road which causes the back end to drift a tad, the lower fronts stop understeering that I was having.
The guy who fitted them only wanted to put 26 in the front, but that's too wallowy in corners if you attack fairly hard....I guess I'm going for the middle ground...........

Kevin
Old 01-16-2004 | 10:45 AM
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Like Robmug, 36 all round on 17 inch wheels, 205 section front and 255 section rear. Best place to try variations is on a track, nb for track driving I drop fronts to 32 hot, maintain rears at 36 hot, might not need to drop fronts to reduce understeer if running a bigger section tyre like Phil does.
Old 01-16-2004 | 11:49 AM
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Originally posted by robmug
17" Cup 1s. 36psi front & rear.

Inteesting that Kevin runs 29/36 and John 36/40

I remember plenty of previous threads on this where someone posted track times and concluded that 36/36 was the best for 17" rims.

I'm sure Porsche did their research when suggesting 36/36 for 17s
I wonder why they suggest equal pressures for 17s and very different (38/44) for 16s. Any suggestions?

Cheers
Old 01-16-2004 | 12:41 PM
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I wonder why they suggest equal pressures for 17s and very different (38/44) for 16s. Any suggestions?
I don't really know, but I can say that running 36/36 on my Cup 1 replicas with 205/255's gives a subjectively much harder ride than my 16" track wheels w/competition rubber (even with the tires set to track pressures of about 34/38 give or take).

Don't know that I would have expected a 1" bigger wheel to stiffen the ride so much, but it sure does. When I first got the car, my dealer had arranged to fit the Cup 1's. When I checked pressure, he had them at 36/36. Of course, I looked at the door plaque, and see that Porsche calls for 36/44, so I immediately bumped them up, thinking my dealer was an idiot.

Cripes, did that ride stiff in the tail! Obviously, I then found the TSB calling for 36/36 with 17's. Much better, but still stiffer than 16's.

BGL
Old 01-16-2004 | 02:03 PM
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17in wheels. Non standard suspension and settings.
Bridgestone SO2`s at 36/36 F/R hot
IMHO the car becomes unstable with rear pressures over 40, its easy to tell when pressures have risen to this level and it`s time to let some air out for me.
MPSC`s 32/32 hot
Old 01-16-2004 | 03:10 PM
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For everday use, I go with 36 psi f/r on 17" wheels w/ 225/255 combo.
Old 01-16-2004 | 03:17 PM
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Are these hot or cold pressure?
Old 01-17-2004 | 10:59 AM
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Cold, at least in my case.

BGL


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