Vwthunders build thread (finally)

[jasonc23]

Congrats on the new PB Troy! Getting closer to me

[vwthunder]

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

[seangti]

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.

[team_v]

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]

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.

[seangti]

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.

[team_v]

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.

[vwthunder]

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 ?

[grandturismo]

What pressure were they at?

[vwthunder]

Ok so a bit if a story from Sunday from Winton, well first of all I dropped from a 1:49.1 to a 1:47.00, guessing due to going from a 205/40 to a 215/45 oh and the harness kept me in the seat a little better.

First session out, well the car was not running that well only boosting to 18psi (N75 problem i think) so i took it easy and managed to get a PB on the 3rd lap. Tires felt awesome, really predictable. Had a bit of a miss/stutter going from 3rd to 4th.

Second session out there was too much traffic, tires did not feel as good, was it just that i was used to them so it was all in my mind. I am no expert on tire science, i know semis have to have heat cycling etc (btw Hankook RS3'3). Rear of the car seemed to want to hop in some of the tight corners. Im thinking maybe the rear was too stiff causing a little understeer in the long sweeping sections.

Third session out and the car had fuel starvation issues on the tight corners. Think this is due to the walbo i just put in (had to midify it to fit) tank was at half.

Any thoughts on the tires and handling ?

[vwthunder]

I managed to fit 215 45's on the rear easily, even added a 5mm spacer for some poke, guess thats the difference between a 35 offset and a 48 which i have

[h100vw]

They are pretty thin, I did anthony's. The backs were not so bad but the fronts need lots of car. There is a tab for the liner, you need to be careful going over that and that there's nothing between it and the wing or the tool shoves that through to the outside.

I think there's some pictures on Anthony's thread

Gavin

[vwthunder]

Do you the arch liners in still? Guards rolled?

Sent from my GT-I9505 using Tapatalk 4

Still has liners in and guards are not rollled.

I have heard that polo guards are very soft and there is a high risk of damage if you roll them


Anyone done it?

[Bullet Fast]

Do you the arch liners in still? Guards rolled?

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[VWindahouse]

Badass!