Vwthunders build thread (finally)

**grandturismo** · 02-10-2013, 09:13 PM

What pressure were they at?

**vwthunder** · 03-10-2013, 12:55 PM

Originally Posted by grandturismo

What pressure were they at?

Hm i didn't think of that, i forgot to take my gauge with me. Think they were at 33 cold, no idea with they were hot.
They increase about 4psi hot do they ?

**team_v** · 03-10-2013, 01:47 PM

Originally Posted by vwthunder

Hm i didn't think of that, i forgot to take my gauge with me. Think they were at 33 cold, no idea with they were hot.
They increase about 4psi hot do they ?

Obviously semi slicks are different (28PSI if i recall) but we were told to get road tyres up to 44psi before we set off.

**seangti** · 03-10-2013, 01:51 PM

Originally Posted by vwthunder

Hm i didn't think of that, i forgot to take my gauge with me. Think they were at 33 cold, no idea with they were hot.
They increase about 4psi hot do they ?

Thats about as low as you'd ever want a street tyre when tracking it. ~36psi min cold on street tyres, I'd run 38 usually but dependent on the tyre sidewall and if it was sprints or happy laps. Happy laps a little lower is ok as you're out there longer and not flogging the tyre or car as hard as sprints. On my Bridgestone R002, 36psi is good. Semi-slicks, I think I ran 30psi.

4psi increase due to temp is a bit low from my experience, 6-8 is what I've experienced. But obviously has variables like wheel/brake temps, cool down lap, track temp, etc.

**seangti** · 03-10-2013, 02:01 PM

Originally Posted by team_v

Obviously semi slicks are different (28PSI if i recall) but we were told to get road tyres up to 44psi before we set off.

On a 60 series tyre perhaps, though a 40 - 45 series that's hefty. I have heard what you've said about running 40+ psi, though it doesn't translate into a great lap time or feel/feedback in the corners. It will make the car more predictable when it slides, it'll let go much earlier, spin much easier, overcook much sooner but protect the sidewalls.

**team_v** · 03-10-2013, 02:04 PM

Originally Posted by seangti

On a 60 series tyre perhaps, though a 40 - 45 series that's hefty. I have heard what you've said about running 40+ psi, though it doesn't translate into a great lap time or feel/feedback in the corners. It will make the car more predictable when it slides, it'll let go much earlier, spin much easier, overcook much sooner but protect the sidewalls.

No worries, it really depends on the tyre and the sizing but i found having mine at 44PSI on a 45 series road tyre made it feel a lot more stable.

I guess the best bet would be to have driver traing and ask the instructor.

**seangti** · 03-10-2013, 02:21 PM

Originally Posted by team_v

No worries, it really depends on the tyre and the sizing but i found having mine at 44PSI on a 45 series road tyre made it feel a lot more stable.

You're on the KU31's aren't you? I found them best when ran at 40psi+ too. There you go, trial and error.

Vwthunder (sorry, I've gone to blank to your name), do you have a lap timer or gps based g-force meter. Most of the lap timer phone apps (Harry's or CMS) have gps based g-force, that'll at least support your perception. A gps based g-force is better than the internal phone accelerometer as it won't be influenced by bumps on the track and doesn't need to be perfectly vertical, etc.

**vwthunder** · 03-10-2013, 03:10 PM

Originally Posted by seangti

You're on the KU31's aren't you? I found them best when ran at 40psi+ too. There you go, trial and error.

Vwthunder (sorry, I've gone to blank to your name), do you have a lap timer or gps based g-force meter. Most of the lap timer phone apps (Harry's or CMS) have gps based g-force, that'll at least support your perception. A gps based g-force is better than the internal phone accelerometer as it won't be influenced by bumps on the track and doesn't need to be perfectly vertical, etc.

Yes Its Troy lol

I do have a propper lap timer which displays g-force, but didn't really have much time to play around with it.
I had been sick a few days before the trackday, had to get the car ready (2days spent) in the cold and winton is 230km from Melbourne so a 4:30am start on the day, after a few hours i was stuffed. I got a good PB so called it a day and came home.

Have to get back there soon, and play around more with the setup