My shop supplied and fitted new Cup2 tires to my GT4 yesterday along with a wheel alignment to prepare for patchy rain forecast today at track.
Discovered car was vibrating quite badly above 190kmh, I'm guessing a bad wheel balance and or bad alignment which happened to a friend as well on a previous event.
My friend found out his was too much toe in the front, so I'm guessing maybe similar. This really detracted from the enjoyment for track as I couldn't extract all that I wanted from the car and it was quite unstable at high speed, never had this issue before. ,.

Another thing that struck me is the fronts are N1 and the rears N0, does anyone know if this is ok or should they have been the same N rating front to back.
I also noticed the front N1 have the rim protector edge but rears don't. Manufacture dates are March 2017 N1 245/35/20 front and June 2017 N0 295/30 20 rears.

 

I'm no expert, but tend to think the N rating mismatch will be fine. You may be able to research the testing and/or Porsche specification difference between the N0 and N1. Perhaps there is not much difference.

 

Thank you and yes it does seem that way.


I just had these comments from a couple friends.
"Hey Jim... saw your post. I have N1 on the front too. OEM on the GT4 was N0 then the GT3.2 has N1 which fits our fronts. Better grip... less understerrrrr"

Same friend
"Rear N1 not available yet... but I expect an N1 to be released with 718GT4 next year. Like GT3.2 it should help the car drop its ring time quite a lot"

Another friend
"The new N1 replaced the old N0 MSC2. Apparently N1 better wet performance"

All good info, the more you ask the more you find out