Watch your pressures!

Wheels, Suspension, Brakes & Tyres questions and answers

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Biggles
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Postby Biggles » Tue Jun 03, 2008 10:14 pm

Geeze, Benny! I hope you held onto them for the next 'burn-out' day!

With your LSD and that sticky rubber, we could coat the pan in tyre goo (that's all that would be left of them with your HP) and you could take the canvas hoops off and throw them away, deeply satisfied that you have wrung every cents worth out of them! :mrgreen:
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Quicksilver
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Watch your pressures!

Postby Quicksilver » Sun Aug 10, 2008 8:48 am

I read on another forum that to check if you hve the right tyre pressures:

1. Inflate tyres to pressure you believe correct.
2. Drive about one hour at 100kph to get full operating temperature.
3. check tyre pressures as soon as you stop.
4. Pressures should now be 4 psi higher than when you started.
5. If higher, tyres are too hot and need less pressure.
6. If lower, tyres are too cold and need more pressure.

I haven't tried this yet on the MX-5 but seems about right on the Commodore and caravan.
Anyone else tried this?
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AJ
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Watch your pressures!

Postby AJ » Sun Aug 10, 2008 9:36 am

too many variables in the scenario quicksilver, that is why the tyre industry adopted the "check pressure at cold" format, the wide variety of profiles in tyres these days preclude your suggested method from being accurate, as well as actually finding an area where you can maintain a constant speed for an hour, one good hard jump on the brakes skews the results completely, as the heat that is radiated out through the rims to the tyre affects the results. The low profile performance tyres we run on our lightweight sports cars react in a different way to heat build up to say a standard 65/75 profile tyre on a family sedan (not that many of them run those profiles these days) I wouldn't take that method as gospel mate, but hey, it's worth a try if you can be bothered. :)
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GP
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Watch your pressures!

Postby GP » Mon Aug 11, 2008 1:05 pm

5. If higher, tyres are too hot and need less pressure.
6. If lower, tyres are too cold and need more pressure.

These 2 are the wrong way around
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Caffeine
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Re:

Postby Caffeine » Wed Aug 13, 2008 12:03 pm

StanTheMan wrote:
wun911 wrote:I only check it because I want better milage.

I have same size wheel and usually aroud 32 psi for me.


wow... I cant handle mine with more than 28.

I guess you don't have super hard bushes :lol: . But my size RT 615's are 50 profile

I run 36 in mine, with the same bushes as you STM!

Not as stiff suspension though I think...
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matt9111
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Watch your pressures!

Postby matt9111 » Thu Aug 14, 2008 4:29 pm

Wow, my tyre pressures are WAY out, the fronts are 28, and the rears are 32, maybe ill, try 36 on the front and 38 on the rear, sound high though?

I used to drive a 4WD in the bush alot, so I never had my tyres above 30, because it took to long to deflate them...lol so lazy.

The reason I run different pressures on the front to the back is I found my car was under-steering a lot more than it should be, it seems to behave a little differently now, but certainly isn't as responsive

Im just on standard rims, and using (please don't laugh, haha but I know you will) Savis somethings on the front 205/45 R16, and Champiro GT's on the rear 205/45 R16's
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bensale
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Watch your pressures!

Postby bensale » Thu Aug 14, 2008 6:44 pm

I've found that around 38-40psi feels a lot better to me than the lower pressures. This is a na6 running the 16' 205/45 nb8b wheels running bridgestone turanzas.

Matt you'll be amazed the difference high pressures will make, pressure seems to make a huge difference with these.

I run slightly higher pressure on the fronts as it seems to improve turn in slightly. Although I am far from an expert though, this is just what feels right to me...
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matt9111
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Watch your pressures!

Postby matt9111 » Thu Aug 14, 2008 6:53 pm

I agree with you on the turn in, but I felt mid corner they'd just overheat and then I'd understeer, but I'm definitely going to try higher pressures anyway, maybe I'll just buy some good tires, haha
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