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      04-30-2012, 02:14 PM   #1
Kgolf31
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Auto-X Tire Pressures

Hello Guys,

I'm coming up my first Auto-X on fresh tread (RS3 235/45/18 and 265/40/18)

Last season I ran on T1Rs and it was a completely different compound and therefor different pressure (not to mention I forget my pressures).

Anyone have decent starting pressures to start w/RS3s or star-specs...Obviously it will change with conditions. I just would like to know cold/hot pressures to work with.

Thanks!
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      04-30-2012, 09:40 PM   #2
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I'll post a spreadsheet later today / tomorrow with data from this year on RS3's 245/275 on an AS classed M.

But I've found they like higher pressures in front vs rear. Front 38-41, Rear 34-37


Hopefully this picture uploads correctly, it was taken in a medium speed right hand 90. You can see a lot of front sidewall flex, this was at 36psi.

Last edited by Trev; 02-23-2013 at 12:33 AM..
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      04-30-2012, 10:22 PM   #3
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Quote:
Originally Posted by Trev View Post
I'll post a spreadsheet later today / tomorrow with data from this year on RS3's 245/275 on an AS classed M.

But I've found they like higher pressures in front vs rear. Front 38-41, Rear 34-37


Hopefully this picture uploads correctly, it was taken in a medium speed right hand 90. You can see a lot of front sidewall flex, this was at 36psi.
Take your time. I don't run til Sunday. It would be greatly appreciated!

Good to know.

I was running like ~37 on my T1Rs last year and they were flexing like crazy:





I finally have a 30mm sway bar up front to reduce roll
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      05-01-2012, 09:33 AM   #4
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What kind of sway bar?
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      05-01-2012, 11:18 AM   #5
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Quote:
Originally Posted by Roffle Waffle View Post
What kind of sway bar?
E46 M3 H&R
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      05-01-2012, 11:31 AM   #6
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bolt on? I want one!
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      05-01-2012, 11:47 AM   #7
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Hmm interesting the front H&R bar fits? Does it need any modifications & does it have any adjustability. I've been considering the Ground Control unit, as the slider approach provides a nice incremental range of adjustment.

You need to tell us how it works.

See attached Tyre condition spreadsheet, its pretty raw data with some opinion on conditions per event. Still dialing in an optimum starting setup, but data indicates higher front pressure & slightly lower rears. The RS3's still spin up like a mo-fo when cold.

Last edited by Trev; 02-23-2013 at 12:33 AM..
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      05-01-2012, 02:19 PM   #8
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Quote:
Originally Posted by Roffle Waffle View Post
bolt on? I want one!
It's at the shop now (I'm still finishing up school here and don't have time to change oil and install the bar before Sunday). TCKline racing confirmed that the bar will bolt right up. So far I haven't gotten any calls saying otherwise.

http://www.tcklineracing.com/webdocs.../Details96.cfm

The owner there was awesome. He raced a Z4M and was very knowledgeable on the chassis. Initially I wanted to go rear bar as well (and add camber plates) to bump into BSP but he assured me that the rear bar will do nothing...but he would be more than welcome to sell me one, lol.

He said he was most comfortable with the front bar and no rear. We'll see

Quote:
Originally Posted by Trev View Post
Hmm interesting the front H&R bar fits? Does it need any modifications & does it have any adjustability. I've been considering the Ground Control unit, as the slider approach provides a nice incremental range of adjustment.

You need to tell us how it works.

See attached Tyre condition spreadsheet, its pretty raw data with some opinion on conditions per event. Still dialing in an optimum starting setup, but data indicates higher front pressure & slightly lower rears. The RS3's still spin up like a mo-fo when cold.
It has 3 hole adjustable holes. I'm starting at the middle hole which is true 30mm and see how it goes. I'll be sure to come back Sunday night and give me rants and raves.

Thanks for the data. I'll start at 38 front and 34 rear and play around with that.
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      05-01-2012, 06:54 PM   #9
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What spring rates are you running?
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      05-01-2012, 07:24 PM   #10
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Quote:
Originally Posted by seank View Post
What spring rates are you running?
OEM, I don't know the rates.
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      05-02-2012, 05:28 AM   #11
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be careful running stiffer ARBS and not re-inforceing the mount... they WILL rip eventually.... i run michelin tyres @ 35psi cold.... ideally i want 40psi hot, i won an event last year with michelin, i spent he day drifting around in porsche, lambos, bmws, i also had the pleasure to spend time with one of the actual engineers for the PS range of performance rubber, he told me they like to get their tyres to the 40psi HOT range as they perform their best @ this temp....

Interesting info for anyone on Ps2/Pss/PScup... their are quite afew of us i believe :-)
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Last edited by Beedub; 05-02-2012 at 06:18 AM..
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      05-02-2012, 10:50 AM   #12
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Quote:
Originally Posted by Beedub View Post
be careful running stiffer ARBS and not re-inforceing the mount... they WILL rip eventually.... i run michelin tyres @ 35psi cold.... ideally i want 40psi hot, i won an event last year with michelin, i spent he day drifting around in porsche, lambos, bmws, i also had the pleasure to spend time with one of the actual engineers for the PS range of performance rubber, he told me they like to get their tyres to the 40psi HOT range as they perform their best @ this temp....

Interesting info for anyone on Ps2/Pss/PScup... their are quite afew of us i believe :-)
I saw this thread awhile ago and looked into it. I'll keep on checking but I was told that light auto-x and minor track duty should do nothing to it.
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