[Z06] shifted to PS2's from OEM GY's and now getting LESS traction??!?!?!
06-25-2010, 04:38 AM
#1
shifted to PS2's from OEM GY's and now getting LESS traction??!?!?!
had the OE GY's on the car since new ('06 Z06). previous owner put low miles on car, and only in the last year since i got her has she been driven and tracked hard. so was down to the wear strips, getting lots of squirm at the back, plus all the other complaints i've read about the GY's.
car is stock other than a corsa, ARH and K&N panel. NO TUNE.
got my bnew Michelin PS2 ZP's recently, and was looking forward to much better traction than the old and bald GY's.
in the past on the GY's, the car would squirm a lot under take off from 2nd gear, but would run hard and with no TC intervention thru 4th gear. now with the Michelins, the TC is just going nuts in 4th gear on the small bumps that never bothered the GY's before!
my buddy's car that i could outrun when starting side-by-side on that road, now pulls level or even slightly ahead because the TC keeps cutting in!
SAME (PERFECTLY STRAIGHT) ROAD
SAME (BONE DRY) CONDITIONS
nothing at all changed on the car in the past month, other than the tires.
pressures are 30psi f/r cold.
i'm guessing (hoping) that this traction issue is because the tires aren't properly run-in yet, and with more miles they will find the grip i was hoping for? i've put just under about 100 miles on the tires before running hard as described above.
i run PS2's on my other cars and have had great experience with them, so was hoping they would be a big step up from the GY's, based also on what i'd read here.
TIA guys!
car is stock other than a corsa, ARH and K&N panel. NO TUNE.
got my bnew Michelin PS2 ZP's recently, and was looking forward to much better traction than the old and bald GY's.
in the past on the GY's, the car would squirm a lot under take off from 2nd gear, but would run hard and with no TC intervention thru 4th gear. now with the Michelins, the TC is just going nuts in 4th gear on the small bumps that never bothered the GY's before!
my buddy's car that i could outrun when starting side-by-side on that road, now pulls level or even slightly ahead because the TC keeps cutting in!
SAME (PERFECTLY STRAIGHT) ROAD
SAME (BONE DRY) CONDITIONS
nothing at all changed on the car in the past month, other than the tires.
pressures are 30psi f/r cold.
i'm guessing (hoping) that this traction issue is because the tires aren't properly run-in yet, and with more miles they will find the grip i was hoping for? i've put just under about 100 miles on the tires before running hard as described above.
i run PS2's on my other cars and have had great experience with them, so was hoping they would be a big step up from the GY's, based also on what i'd read here.
TIA guys!
or there is something else not right.
06-25-2010, 10:09 AM
#5
thanks!
06-25-2010, 12:11 PM
#7
Le Mans Master
From day one I couldn't even brake my PS2's loose and I have 600 RWHP, so if it's not because your tires are brand spanking new I would send them back as defective. They are far and away a much better, super sticky tire!!!
06-25-2010, 12:16 PM
#8
Which size did you get? Just curious since I think the new ones are correct, but last year there was one which would "fit" but could cause problems (at least that's what my tire guy told me - for what it's worth).
06-25-2010, 12:22 PM
#9
uh oh... i live in Asia (shipped the tires in from the U.S. because they do not sell ANY tires here in my country in Z06 sizes)
06-25-2010, 01:44 PM
#12
06-25-2010, 02:04 PM
#13
Le Mans Master
07-12-2010, 02:48 AM
#14
bit of an update.
the tires now have close to 200 miles on them-- many hard driving (up to 140mph) miles, and i'm still getting the same problem.
i have MUCH better traction taking off. with the OE GY's, getting on the gas in 2nd in a straight line (even gently squeezing the throttle,) i'd get the rear all squirrely, sometimes all the way almost into 3rd gear. but into third and fourth with the GY's, i could just keep the throttle floored and no problem.
now with the Michelin's, i can get on the gas aggressively in 2nd, and the car just scoots. in 3rd, its solid. but once into 4th and high speed, the TC just starts to cut in and out as long as you're on anything but a perfectly smooth road. i tried it in 5th, and i'm getting it too (albeit much less).
its really annoying because its like there's an HP limiter in 4th gear, as the TC just cuts in and out robbing the power, whereas in the past it never would do that.
in all the above, i'm using the SAME stretch of road with the same conditions.
nothing else was done to the car since i changed the tires, so the only variable is the Michelins. again, in all other conditions other than speeds above say 120mph in 4th, the tires are better than the GY's in every way.
the one thing i've done differently this time is to put nitrogen in the tires. i'm wondering if that has anything to do with it? i can't imagine it would, but nitrogen is supposed to produce somewhat different ride characteristics than regular air, and is it possible that the slight difference in resonance is confusing the T/C?
i know i know, what a silly long-shot, but at this point, i can't see what else it could be...
i will replace the nitrogen with air and then try again.
the tires now have close to 200 miles on them-- many hard driving (up to 140mph) miles, and i'm still getting the same problem.
i have MUCH better traction taking off. with the OE GY's, getting on the gas in 2nd in a straight line (even gently squeezing the throttle,) i'd get the rear all squirrely, sometimes all the way almost into 3rd gear. but into third and fourth with the GY's, i could just keep the throttle floored and no problem.
now with the Michelin's, i can get on the gas aggressively in 2nd, and the car just scoots. in 3rd, its solid. but once into 4th and high speed, the TC just starts to cut in and out as long as you're on anything but a perfectly smooth road. i tried it in 5th, and i'm getting it too (albeit much less).
its really annoying because its like there's an HP limiter in 4th gear, as the TC just cuts in and out robbing the power, whereas in the past it never would do that.
in all the above, i'm using the SAME stretch of road with the same conditions.
nothing else was done to the car since i changed the tires, so the only variable is the Michelins. again, in all other conditions other than speeds above say 120mph in 4th, the tires are better than the GY's in every way.
the one thing i've done differently this time is to put nitrogen in the tires. i'm wondering if that has anything to do with it? i can't imagine it would, but nitrogen is supposed to produce somewhat different ride characteristics than regular air, and is it possible that the slight difference in resonance is confusing the T/C?
i know i know, what a silly long-shot, but at this point, i can't see what else it could be...
i will replace the nitrogen with air and then try again.
07-12-2010, 07:31 AM
#15
Safety Car
Try raising the pressure to 32-33 lbs. Tires filled with air will increase pressure when they get hot, and the suggested pressure (30. Lbs) will have that in mind. The nitrogen will not change pressure with temperature changes.
It may not help, but with a try.
It may not help, but with a try.
07-12-2010, 08:46 AM
#17
Drifting
Member Since: Feb 2007
Location: Alpharetta Georgia
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I am beginning to think that you are having TC/Active Handling issues not associated with the tires mechanical grip level. Can you confirm the correct size tires were installed?
07-12-2010, 09:27 AM
#18
Le Mans Master
07-12-2010, 11:25 AM
#19
- front size 275/35/18
- rear size 325/30/19