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After track alignment setup per GM and going to Laguna Seca, my tire wear wasn’t even, outer edges got more worn out, so clearly need more camber, what are you faster guys using for setup?
It could also be that your tires were under inflated. What pressures did you end up at when you were up to temp?
Also what tires? A lot of newer tires like the PS4 and Cup 2 tires have a softer compound on the outer edge for increased grip while the inside 1/3-2/3 will be harder for longevity.
Do you drive it on the road? I’d say -2.5 is going to wear the insides faster on the street. You may find it balances out. On the C7 I was always wearing out the insides first on the racetrack and the outsides first at autocross. Same camber, just a different application.
It could also be that your tires were under inflated. What pressures did you end up at when you were up to temp?
Also what tires? A lot of newer tires like the PS4 and Cup 2 tires have a softer compound on the outer edge for increased grip while the inside 1/3-2/3 will be harder for longevity.
Do you drive it on the road? I’d say -2.5 is going to wear the insides faster on the street. You may find it balances out. On the C7 I was always wearing out the insides first on the racetrack and the outsides first at autocross. Same camber, just a different application.
90% track, 10% street(if that), lol. Tires had 25 miles on them before going on track
Can't help you with the camber as I'm running the suggested track alignment (and probably not one of the "faster guys" anyway), but think you might want a little more tire pressure. The PDR is excellent for figuring this out by the way. Here's my lateral G versus tire pressure for a session. You can see 34-35 seems to give me a little more grip. Thanks to Poorsha for the head start on the PDR stuff.
I'm at -3 in the front and -2.5 in the rear. Decent wear pattern on Nankang CRS but still more pronounced shoulder wear. I got 4 track days (8 hrs on track) and some street mileage on my first set of tires.
From: South Lousiana (Cajun Boys with Bad ASS Toys)
Do the C8 ZO6's come in a track alignment ? in that to NOT wear a set of tires out on the street, you'd need a Street alignment??(i had the street alignment did on my c7 ZO6
The Z06's come in an aggressive street alignment, but it actually varies a lot as the Camber spec ranges from -0.5* to about -1.5*. Chevy recommended track camber is -2.0* and appears to be not enough.
Street alignment from the factory also sometimes has too much toe which, when combined with a lot of camber, will wear out the tires very quickly in normal street driving.
If you are looking for good street tire wear and re willing to give up .05 Gs of ultimate cornering (when did you pull more than .9 Gs on the street? last week for me) then camber of -0.7*F and -0.5*R with minimal toe-in at both ends should give you the best tire wear.
The Z06's come in an aggressive street alignment, but it actually varies a lot as the Camber spec ranges from -0.5* to about -1.5*. Chevy recommended track camber is -2.0* and appears to be not enough.
Street alignment from the factory also sometimes has too much toe which, when combined with a lot of camber, will wear out the tires very quickly in normal street driving.
If you are looking for good street tire wear and re willing to give up .05 Gs of ultimate cornering (when did you pull more than .9 Gs on the street? last week for me) then camber of -0.7*F and -0.5*R with minimal toe-in at both ends should give you the best tire wear.
You can run more negative camber than this and still get excellent wear characteristics on the street. I'm running -1.8F and -1.5 rear with .1 toe and i have very even wear on PS4Ss after 6,000 miles.
I'm at -3 in the front and -2.5 in the rear. Decent wear pattern on Nankang CRS but still more pronounced shoulder wear. I got 4 track days (8 hrs on track) and some street mileage on my first set of tires.
Which sizes are you running, and rims? I think -3 all around might be a good choice, I think GM wanted -2, but for tracks like Laguna, not enough clearly, and I wasn't running full speed yet, still getting used to car, managed to get a 1:35 there, car can do easily 1:30, maybe even into the 1:20's range, the Cup2 R are superb tires, never felt i was on the edge anywhere on the track, so ya, lots more speed there to be had.
Which sizes are you running, and rims? I think -3 all around might be a good choice, I think GM wanted -2, but for tracks like Laguna, not enough clearly, and I wasn't running full speed yet, still getting used to car, managed to get a 1:35 there, car can do easily 1:30, maybe even into the 1:20's range, the Cup2 R are superb tires, never felt i was on the edge anywhere on the track, so ya, lots more speed there to be had.
I'm running 295/30/19 front 325/30/19 rear Nankang CRS v2. I agree on the amazing grip of the Cup2R, I drove a friends Z07 with Cup2R on the same day as my car and was 3 seconds faster. He is only getting 2 track days out of his Cup2R though, so I'm getting double the life with the Nankangs.
I'm running 295/30/19 front 325/30/19 rear Nankang CRS v2. I agree on the amazing grip of the Cup2R, I drove a friends Z07 with Cup2R on the same day as my car and was 3 seconds faster. He is only getting 2 track days out of his Cup2R though, so I'm getting double the life with the Nankangs.
What size Rims did you get and what did these BC Forged ones run you? With losing 20mm per side, 40mm total in back, have you noticed grip loss?
What size Rims did you get and what did these BC Forged ones run you? With losing 20mm per side, 40mm total in back, have you noticed grip loss?
19x10.5 and 19x12. It's got more grip than stock PS4S, but less than Cup2R in exchange for longevity. It will oversteer at the limit which I prefer. Big upside vs Cup2R is the Nankang's handle heat very well, are consistent until they chord, do not fall off during a full session, and are driveable on the street even in the rain.
Can't help you with the camber as I'm running the suggested track alignment (and probably not one of the "faster guys" anyway), but think you might want a little more tire pressure. The PDR is excellent for figuring this out by the way. Here's my lateral G versus tire pressure for a session. You can see 34-35 seems to give me a little more grip. Thanks to Poorsha for the head start on the PDR stuff.
Interesting data, but another explanation might be that you are driving more aggressive as the session goes on. I know that my lap times almost always trend down as a session progresses, and my last lap is often my quickest. The other factor is that traffic usually thins out over time, so the opportunity of a free lap increases. Of course this is a function of where you start at the start. To confirm ideal pressure as the key variable, you would need to show a decrease in traction above a certain pressure.
Before you adjust your camber more, I would at least recommend trying to hit the upper end of the recommended pressures at 35PSI hot.
With a double wishbone suspension you might not need a super aggressive negative camber to maintain a flat your contact patch through corners. With such a heavy car pulling so many G's, your might be more prone to having the sidewall roll over a bit more than you might expect.
Also regarding tire and wheel choice, I'm going to be going for the Continental ExtremeContact Sport 200tw tires in 295/30-19 front and 345/30-19 rear, this maintains almost the exact same diameter differential as stock, but with about a .5" reduction to both tires. The tire is intended for endurance racing and has been tested by grassroots motorsport to comfortably run at 10/10ths for 8 hours. So this seems like a very solid option for the Z06. It will not be as grippy as the Cup 2R but it will last a lot longer and cost nearly $900 less per set.
Before you adjust your camber more, I would at least recommend trying to hit the upper end of the recommended pressures at 35PSI hot.
With a double wishbone suspension you might not need a super aggressive negative camber to maintain a flat your contact patch through corners. With such a heavy car pulling so many G's, your might be more prone to having the sidewall roll over a bit more than you might expect.
Also regarding tire and wheel choice, I'm going to be going for the Continental ExtremeContact Sport 200tw tires in 295/30-19 front and 345/30-19 rear, this maintains almost the exact same diameter differential as stock, but with about a .5" reduction to both tires. The tire is intended for endurance racing and has been tested by grassroots motorsport to comfortably run at 10/10ths for 8 hours. So this seems like a very solid option for the Z06. It will not be as grippy as the Cup 2R but it will last a lot longer and cost nearly $900 less per set.
I reached out to the lead instructor at Ron Fellows Corvette Race School, he actually said that the Laguna Seca racetrack just creates a tremendous amount of force in those banked corners and probably need more camber to handle it. He also said the PSI I was running was fine. The tire wear I experienced is very unusual, because normally like on my 718 GT4, I get lots of wear on the very outer edge of the tire, but with the Cup2R on this Z, it was totally even across the contact patch, it just wore more gradually down from inside to out, so havent experienced that yet on any track car i've driven, inside patch has like 80% left, outside edge like 40%, but flat across. But YES YES YES, I wont be running $2700 set of tires again, I will also be going to 19's and hopefully the Continentals or Cup2, but sadly, seems both of these tires are on back order and have no ETA, as per TireRack website. And Forgelines for rims, seems like best option out there.
-2.5 not enough?!?
