I'm looking at buying my first set of shaved tires for autocross duty. I would like to be able to drive to and from events without swapping tires once I get there. I'm thinking about the Dunlop *specs in 245/40/17. Any suggestions on a good depth? 6/32? 4/32?

Thanks!
Eric

 

what are shaved tires

 

Shaving is a process of removing some specified amount of the original tread so as to minimize tread block squirm and the associated heat generation. Basically, you sacrifice some of the original tread to improve performance.

For reference: Shaving tires

 

yup yup this is true. read up and do some research hoser

 

I always ran my Z1s at full thread.

Are you running STU?

 

No problems with chunking at full tread? I'm on stock suspension and can't get enough negative camber out of the front to keep the tires off of the outside shoulder. I can keep the tires from rolling over with pressure, but the shoulder still gets beat to hell.

I'm looking at running STU next season once I can put some money into a high quality set of coilovers. For now, I'm running in a local Street Tire A Stock class. I run AS when I'm out my home region, but after being dominated by s2000's on slicks today, I might just run STU--with the understanding that I won't be competitve against divisional/national level cars and drivers. But hey... it' my first full year.

Eric

 

None - also ran this for HPDE.

Are you using the -2 camber bolt selection?

I run -1.7 up front and have never run over on the outside shoulder (34-36 front psi).

Which region are you running with? SVR, Detroit, WM?

 

The alignment was set with the eccentric bolt in the -2 position. I think that got -1.6/1-8 or so. I'm running hot pressures around 40 psi (depends on surface). Maybe my description is too harsh: I'm noticing that the outside shoulder wears more than the rest of the tire. Chalk marks tell me I'm not running over onto the side wall. I just assumed it was normal to wear the outside shoulder of the tire more than the rest of the tread.

I'm a Detroit Region homer, but I've driven with SVR, WMR, the Furrin Group (Western Michigan non-SCCA), and I was down in Ohio today with NWOR. I've had a busy summer to this point.

 

Ah, with negative camber, you should be wearing the inside more. Any toe?

Cool. I ran with Detroit and SVR when I still lived in MI. If you see a silver RA at the Oscoda meet thats otter.

 

Oh, for what its worth, I run 245/45 Z1s. I like the slightly taller tire to give me more 2nd gear.

 

The car isn't driven much on the street. 0 Toe all the way around. I can see wearing the inside more with negative camber if the car is driven all the time, but with as much autocrossing as I'm doing, it seems that the inherent tendency of a macpherson strut car to lose camber under dynamic conditions would lead to increased outside wear. Particularly with all the work the tires are doing on an autocross course.

If you've had good luck with Z1 star specs at full tread, I might just give those a shot. I think I met Otter briefly up at Oscoda earlier this year. We talked briefly about how rare stock Evo's are.

 

I guess they are these days. Stevo_MR still has a stock IX MR. But he is near Indy now. Otherwise, he'd be there running STU with you.

Yep, great results with the Z1s at full thread.

 

If one shaves the majority of orders I've ran have been 4/32 for dry, 6 if they are going to see any wet track. Spilt the difference and go 5 if you're not sure.

 

For autoX, it's not uncommon to beat the hell out of the outside shoulder if you're not running enough negative camber and 3 degrees is not quite enough, especially with the Z1's.

 

That's what I was thinking. Especially because at the moment, I'm limited to stock camber adjustment. Lots of good info. Thanks guys!