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Posted: Tue Jan 17, 2006 3:11 pm
by Bevan
I ride on 34 cold. Any higher is too harsh.

On a track day, I put it up to 38 cold which equates to around 44 hot on the track.

Posted: Tue Jan 17, 2006 3:30 pm
by Okibi
I use to run my 17"s about 40-42, i guess because the profile was pretty low i was paranoid about the sidewall flexing too much and hitting the rim.

I ended up chewing up the insides of my tyres in the process.

Take a look along the inside edge might be a good sign your running too much pressure.

Another solution is the mark your tyres with some chalk, lower the HOT psi temp by say 2psi each time until you find a happy medium.

Posted: Tue Jan 17, 2006 5:13 pm
by Matty
~30psi max. any more and the ride is too harsh.

Posted: Tue Jan 17, 2006 5:27 pm
by JBT
30-33psi cold. Tyres are 195/50 15. The car feels skittish on normal road surfaces with them any higher.

Posted: Tue Jan 17, 2006 5:37 pm
by Okibi
What tyres are they?

I run my 15" Toyo T1-Rs at about 34-36PSI (cold) but that's no use to you because you're running a different profile and tyre. :roll:

Posted: Tue Jan 17, 2006 5:57 pm
by JBT
Bridgestone Turanza

Posted: Tue Jan 17, 2006 6:18 pm
by Okibi
Having a quick look at their website..

the ER-33 goes as low as 45
the ER-30 goes as low as 45

What type of Turanzas are they?

Posted: Tue Jan 17, 2006 6:22 pm
by Craig
ER30's in 195/50/15

Re: What psi? - That is the question

Posted: Tue Jan 17, 2006 6:27 pm
by Okibi
Mick_98MXV wrote:...Quick Fit told me to put 40psi in the front and 38psi in the back of my 205x40x17 tyres.


Ok i'm confussed. :?

Posted: Tue Jan 17, 2006 7:33 pm
by smiles
I run 32 psi all round on 205/45/16.

I think 40 is too high and the car will feel skittish, for such a light car. Start with something lower and just monitor the wear and make small changes.
After going for a hard drive on the weekend, the wear is even so I'm sticking with 32. The tyres felt great around bends too.

Posted: Tue Jan 17, 2006 8:13 pm
by npn4875
Like Boags said, I run 40 cold for the road and 45 for the track. The SP is standard NB suspension, no mods, and irons it out pretty well. It may be a bit skittish if (when) I put Teins all round and set 'em hard as a rock ;)

Posted: Tue Jan 17, 2006 8:31 pm
by Caffeine
34 cold here too.... 204/45-16 yokohama CDrives.

I ran the same with the stock Turanza ER30 and yokohama A539's, both in the same size

Posted: Tue Jan 17, 2006 9:33 pm
by Garry
205 45 16's 32 cold all round for general cruising and 33 for going fast

re

Posted: Tue Jan 17, 2006 9:47 pm
by rain902
i am nowhere near an expert at this sorta thing - but heres my humble contribution anyways...

i run 40pseez in my work car coz it has really ordinary tires, and i want the extra crispness (and economy) but i start @ 26-28 pseez on the track rubber...

bear in mind that for everything there is a cause and effect - running any tires with higher pressure will make them stiffer, but reduce the contact patch on the road, thereby lessening grip.

silly me forgot to adjust pressures @ winton during the rain a few months ago, as the day wore on a dry line appeared, my hot pressures were up around 40psi (optimum for those tyres is low-mid 30s) and i had a really well defined wear mark in the centre third of the tyre. :shock: I didnt record any faster time on the dry run with the wrong pressure than i did on the wet runs with the right pressure. :oops:

Running asymmetrical pressures (eg 30 front/34 rear) is a good way to subtly change the handling characteristics of your car. i think that most sedans and stuff call for higher pressures in the rear to compensate for the additional weight of rear passengers and luggage etc - things that dont really factor into a -5 drive :D

fwiw i generally have 2 pseez lower on my drive tyres to give the better compliance/adhesion.

We are all running different pressures - i guess that you can guess that it all comes down to a manufacturer recommendation to start with, then personal preference for the fine tuning! trial and error, my friend. trial and error.


ps has anyone ever put air in their tyres @ a service station (those fancy digital things that they use to stop ppl stealing their air thingy) then gone to a different station and checked the pressures? i did it for a laugh the other week - had pressures ranging from 18psi all round, to 44psi all round. scary! never trust one of them again :shock:

Re: re

Posted: Tue Jan 17, 2006 9:56 pm
by Okibi
rain902 wrote:..ps has anyone ever put air in their tyres @ a service station (those fancy digital things that they use to stop ppl stealing their air thingy) then gone to a different station and checked the pressures? i did it for a laugh the other week - had pressures ranging from 18psi all round, to 44psi all round. scary! never trust one of them again :shock:


I have a hand held tyre pressure gauge i keep in the glove box and always use that to check.

So far my local BP has been spot on with the calibration of my gauge. :D