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re: competition tyre pressure

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Old Aug 17, 2006 | 06:16 AM
  #1  
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re: competition tyre pressure

Hi Guys,

I am using the OEM bridgestone tyres - can anyone suggest a good tyre pressure for doing Hill Climb or short Sprint work?

I am thinking 30psi all around - I have had a search on the forums but can't find any good information.

Thanks,


Deano.
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Old Aug 17, 2006 | 06:30 AM
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Originally Posted by deano
Hi Guys,

I am using the OEM bridgestone tyres - can anyone suggest a good tyre pressure for doing Hill Climb or short Sprint work?

I am thinking 30psi all around - I have had a search on the forums but can't find any good information.

Thanks,


Deano.
36 PSI COLD... That right Taka???
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Old Aug 17, 2006 | 06:40 AM
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Wouldn't the increased pressure give me less grip?

I am only doing 1.2km sprints with no tyre warm up.
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Old Aug 17, 2006 | 08:19 AM
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At the Nats last year we found 36lb HOT was about right.This translates to around 30lb cold.
Cheers
Len
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Old Aug 17, 2006 | 05:21 PM
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And don't forget to have a quick check of the pressure immediately after each run (right Len?).
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Old Aug 17, 2006 | 11:23 PM
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Agree with MACCAA,

but with shorter climb you might want to have around 37or 38. I have 34psi hot with my slick at Winton!
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Old Aug 17, 2006 | 11:49 PM
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Originally Posted by takahashi
Agree with MACCAA,

but with shorter climb you might want to have around 37or 38. I have 34psi hot with my slick at Winton!

Hi Taka - its hard to compare a slick to the oem bridgestone though.

I'm going to start at 30PSI - I will do one run at 36PSI as an experiment once I am up to speed - will post the results.
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Old Aug 18, 2006 | 12:39 AM
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I use to track my OEM bridgestone at Sandown.

Syd is a bit warm today and warmer in Qld?

36 hot is the lowest you go. The lower the pressure - the more heat you generate - so don't need that low pressure! I think 36 hot is good starting point - do you have a pump if you need more?
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Old Aug 18, 2006 | 12:43 AM
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Originally Posted by takahashi
I use to track my OEM bridgestone at Sandown.

Syd is a bit warm today and warmer in Qld?

36 hot is the lowest you go. The lower the pressure - the more heat you generate - so don't need that low pressure! I think 36 hot is good starting point - do you have a pump if you need more?
Hi Taka - remember I am only doing 1.2km - thats the equilivant of what, 1/3rd of a lap at Sandown? - zero warm up, and full speed right from the start.

Do you still reckon start with 36 ?

I need maximum grip - the tyres will generate very little heat over that distance even at full speed.
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Old Aug 18, 2006 | 12:48 AM
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I suggest to have 34psi cold at least if not 36 cold to start with

Measure the tyre pressure after 1st run. I suspect it will go above 40psi. Drop it down to 38 psi HOT and try again. Drop further if you like after 2nd run.

Last edited by takahashi; Aug 18, 2006 at 12:51 AM.
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Old Aug 28, 2006 | 05:52 AM
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Hey guys,

I thought I'd post my results.

The quickest time was from 28psi all round. I would consider trying 26psi but am a little worried about the tyre rolling onto the side wall. At 28psi with the hardest cornering you could imagine - no marks on the side wall so tyre roll is hot a problem at that pressure with the OEM bridgestones.

I did a run at 36psi and another at 40psi - it was traction control city. Sure the car started to turn really easy - but I had zero grip.

28psi gave far better grip levels and resulted in a lot less work from the traction control system.

Everyone at the hill climb was very impressed by the RX8 launches - 6000rpm seemed to yeild the best results.

5 of us got to take some CAMS officials for a hot lap after the event which let me do a launch from 9000rpm on the rev limited. Smoked both tyres for about 200 metres - felt awesome and also a crowd pleaser.


Bring on the turbo!!

Deano.
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Old Aug 28, 2006 | 06:51 PM
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Woohoo! - not sure I'd be game to drop the clutch at 9K.

Glad to see you're having lotsa fun.
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Old Aug 29, 2006 | 08:33 AM
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Originally Posted by Revolver
Woohoo! - not sure I'd be game to drop the clutch at 9K.

Glad to see you're having lotsa fun.

I kind of slip it for a second then let it out - its all good.
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Old Aug 29, 2006 | 09:02 AM
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Hmmm....is that the stock clutch?
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Old Aug 29, 2006 | 10:13 AM
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Originally Posted by timbo
Hmmm....is that the stock clutch?

Yes - no slippage at all.
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Old Aug 29, 2006 | 07:02 PM
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Originally Posted by deano
Yes - no slippage at all.
...yet!
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Old Aug 29, 2006 | 07:19 PM
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Originally Posted by Revolver
...yet!

oh well - better the clutch than the gearbox :-)
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Old Aug 29, 2006 | 07:22 PM
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Originally Posted by deano
oh well - better the clutch than the gearbox :-)
Correct!
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