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I got from a person in Germany who works closely with various teams who have AMG GT4s. As of now he is checking his options to see if he can get more parts so as of right now he is on hold.
Awesome, thanks for the input! Please keep me posted if you hear back, I'd really appreciappreciate it!
Track day today. New psc2zp installed feb 28. Rear felt loose all day. Cold tire pressure 25psi, 32-33 hot psi. Had worse times today than my previous track days. What did I do wrong? Right Rear Left Rear Alignment Specs
There were quite a few reports of the ZPs delaminating on the Corvette forum a couple of years ago, but it was normally the centre block outside of the one that delaminated on your car. It’s hard to say what caused the failure on your tyre as your starting pressures were normally perfect for that tyre. I wonder if your alignment was off; (toe?), placing too much stress on that portion of the tyre.
First track day on those tires. They were installed feb 28. Yesterday was extremely hot here in PR. No track days since then. I will change alignment shop for next track day. Where do you guys buy shims? From M-B service department?
I had the car set up with -2.5 camber at all wheels and kept the OEM toe and caster. Handled very well with even tyre wear.
I think using a different alignment shop is wise, since as you know you can not change camber without changing shims, which you get from the nearest MB dealership.
Good luck, but if those tyres were new, and not old stock, your alignment is highly suspect IMHO
AMG GTBS, AMG GTR Pro, AMG GT, C63 AMG, Porsche Panamera 4S, RX-7 FC Turbo II
Originally Posted by jlrv
Track day today. New psc2zp installed feb 28. Rear felt loose all day. Cold tire pressure 25psi, 32-33 hot psi. Had worse times today than my previous track days. What did I do wrong?
There are so many variables. Away from the car and tires, many tracks are green and not rubbered in for this time of year following COVID related shut downs. Sometimes the lap times are just not there.
I agree with Case 1906 that there are quite a few variables.. Those tire pics really look like some serious track cornering pressures along with possible braking wear... I haven't had my GTRA on a track and probably will not.. but when I ran a 96 TT Gemballa Porsche from Sebring to Watkins Glen (member at VIR) I found out very quickly that street tires were not going to work.. I know they are much, much better today but a track slick will always get you around better.. So I would get a second set of rims and go have fun.. Why tear up street tires when the slicks will always be faster ? In club racing, tires are disposables and you just experienced some of the cost of tracking one's car...
Rear tires removed today. Both failed at the same section. Seems more like tire defect than alignment issues.
Rear Left Rear right
That is the exact type of failure people were seeing on Corvette forum.
What is the date of manufacture of those tyres, and have they been exposed to extreme cold weather during storage, etc?
If they were ‘new’ just before going to the track you should take them to your Michelin dealer to try and get credit from Michelin for that type of failure.
Again though, get the alignment double checked.
Did you take it somewhat easy on your first and second lap out to allow the tyres to come up to temps correctly, as the ZPs do not like to be abused when ‘cold’?
Don't know the manufacture date. Hot and humid weather in Puerto Rico all year long. Track day ambient temp on Saturday around 90F. First couple of laps took it easy. I ordered new set of the regular MO sport cup 2 from tire rack. No more ZP for me. Once new tires are installed will recheck alignment. I had fun anyway. Three 20 minute sessions.
Don't know the manufacture date. Hot and humid weather in Puerto Rico all year long. Track day ambient temp on Saturday around 90F. First couple of laps took it easy. I ordered new set of the regular MO sport cup 2 from tire rack. No more ZP for me. Once new tires are installed will recheck alignment. I had fun anyway. Three 20 minute sessions.
Manufacture date will be stamped into the rubber on the side. Its a 4 digit number, first two digits are the week, second two digits are the year.
06-25-2020, 12:32 AM
