Autocross tire pressure help

[GTIfan99]

I am. When I’m done mopping the floor with you. 15 years old when you started…35 years of experience and still a fool, 50 years old. Did I miss something?

Yes, how did you manage to get 235's to rub in the front with such an amazing setup? You stance bro?

Life is going to be hard for you. Everyone in the autocross threads share info, agree, disagree, try different things, and help each other. Stop acting like a douche canoe or your time on this forum will likely be brief.

 

[krs]

I am. When I’m done mopping the floor with you. 15 years old when you started…35 years of experience and still a fool, 50 years old. Did I miss something?

You going to be at Packwood I’d assume? I mean it’s pretty close to you.

 

[mrmatto]

@GTIfan99 You're such a fOrUm FoOl!

 

[GTIfan99]

@GTIfan99 You're such a fOrUm FoOl!

I know and my car is trash.

Funny development, he reported me and got himself banned.

 

[xXDavidCXx]

Was killing it until the DSG shifted to 3rd approaching the last sweeper, then didn't downshift and tried to pull 3rd from 28mph. At the time I didn't know what had happened and didn't understand the lack of power. It explained some similar behavior at other events. I'll be able to pop it over to manual to prevent the upshift, or downshift it entering the sweeper If I need to.

The thing is so quiet and deceptively quick on course.

Man, I hated Pungo, don't miss that place.

Here's some advice for DSG drivers.

I put it in manual, then I listen for the upshift to third.

Approaching turns where I think I'll slow, I click off a down-shift.

If it goes to second, sweet!

If nothing happens, you should still be in second, sweet!

If it goes to first, you are really slow, be careful on track out!

 

[SouthFL_Mk7.5]

Observations from today. Last outing with 1 degree less negative camber we were running 40psi up front. Today with 1 deg more negative camber (-2 total) we’re running 38psi with better grip and proper sidewall scrub marks. Same ambient temperature as last outing. 225/45/17 660’s.
We run the same pressure in the back as front.

 

[SouthFL_Mk7.5]

Today’s wear.

 

[IES99]

My son runs 40psi all around on his 660’s on the GTI at the local autocross.

That's what I did at SC SCCA this weekend. I see so many other people adjusting tire pressure between laps. Is softer better for traction? I am running Michelin PS4 on stock wheels on my 2017.

 

[enobiko]

That's what I did at SC SCCA this weekend. I see so many other people adjusting tire pressure between laps. Is softer better for traction? I am running Michelin PS4 on stock wheels on my 2017.

I run 38 cold, on PS4S tires, I don't check and reduce pressures between runs. I could, but I think any issues are due to the nut behind the wheel, not tire pressures. I check for roll-over on the sidewalls, so I won't reduce these pressures much, if at all.
Those with track day tires may run lower pressures, assuming the sidewalls are stiffer. That's my guess... Some tires may work better with lower pressure, or depending on the track...

 

[DerHase]

Since I'll actually be autocrossing this year - what's a decent pressure range to start with for Kumho V730s for those who've run them?

For reference:
17x9 wheels with 245/40R17
Stock shocks and springs, 26mm H&R front AND rear sway bars, 034 camber plates

 

[xXDavidCXx]

That's what I did at SC SCCA this weekend. I see so many other people adjusting tire pressure between laps. Is softer better for traction? I am running Michelin PS4 on stock wheels on my 2017.

What’s important with tire pressure is you need enough to support the tire and the weight of the car.

Stiffer springs, less camber, and/or softer sidewalks need more pressure.

 

[GTIfan99]

Since I'll actually be autocrossing this year - what's a decent pressure range to start with for Kumho V730s for those who've run them?

For reference:
17x9 wheels with 245/40R17
Stock shocks and springs, 26mm H&R front AND rear sway bars, 034 camber plates

I ran them last year. At -2 front camber, they seemed pretty happy 35 to 36 front hot.

 

[MonkeyMD]

I ran them last year. At -2 front camber, they seemed pretty happy 35 to 36 front hot.

Less grippy surface, I like 35 F 37.5 R.
Grippier surface, like 37 F 41 R

Had a codriver today who is usually top 3 pax & this was his comment with the pressures on less grippy surface.

It was really fun to drive. The balance of the car was actually nice once I started to understand the car after a few runs. It was just such a shock to my sense going to that from the ND2.

I really liked how the car was so willing to rotate on turn in, though. After driving the ND, it was nice to get some turn in oversteer again.

 

[mrmatto]

Ran v730s this weekend at 34f/35r on a good surface (the FIRM). Car was overall pretty planted and neutral feeling, but I don’t think I pushed the tires completely to their limit most laps. (Until the last lap when I understeered off the track)

My first event on these tires and I liked them. Not sure what happened on that last lap. I think I just overdrove them because the rest of the run felt good.

255/40r17

 

[GTIfan99]

I've been running the RT660 at 35 psi 255 40 17.

Ran 60.5 ish three runs in a row, dropped pressures to 33 psi, ran 59.5.

I don't think the RT660 like higher pressures. The old RE71R's didn't like less that 38 psi.