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I just had this surreal experience at nicksm3 trackday at NYST.
I was on my rear RR 295/30/19 third day and front RE050A 285/30/19 second day.
I brought with me new sticker 265/35/19 MPSCup2 as spare. These are nice as spare because I can mount them on either front or rear to come home. Alas, I am saving them for Lime Rock on Oct 24th. I already established that any soft tire is not economic to run at NYST because the surface is abrasive.
Anyway, this Oct 1st trackday was open track, perfect dry 60 degree sunny day. I have just gotten my rear JRZ back from rebuilt.
So every thing was perfect to tune the rebound and compression. I started with what worked on the front and set the rear to be the same.
So started the day on:
Front: Rebound 15, shaft 15, canister HS 15, LS =5
Rear : same
Car was understeering at 1:38-1:39 pace and not that happy. Since I have the pots mounted I drove when the GS display on the pots page and was looking at the pots movement in mm. Not in mm/s.
My max healthy movement at the front is -30mm (full compression) and 30mm (full extension) using a 75mm pots
Rear -60 compression and 60mm extension using 120mm pots
The GS display showed too much movement and I felt the car roll too much at the fast turns 8-9-10 sequence.
The format of the day allowed me to make adjustment, drive few laps and come off for few more laps. Rinse and repeat.
To make a long story shorter, I arrived to a happy car setup as such
Front HS 16
Rear Rebound +1 to 16, Compression +2 to 17.
The car was still understeering at the slow corners but felt great at the fast turns.
I also tried to bring hot PSI on the front to 38, but got at back to 35psi.
At NYST the passenger side works the hardest. Temp on the rear passenger RR were uniform across and over 150. We took the rear camber from -2.2 to -2.0 and I was curious to see if the inside will overheat less. According to the RR spec it can go up to 220 deg. So perhaps I was not getting enough temp into it, but my front was the issue anyway.
The front passenger was uniform close to 160deg and it was a good because I took the camber from -3.5 to -3.4. so the 285 was not rubbing the fender, and temp were still uniformed across.
The only fly in the otherwise perfect day is that the RE050A was understeering as the day progressed and the pace of 1:38-1:40 was not as fast as the first day on that tire.
Wear was excellent and after two days I can definitely go a third day on it. Alas, I will not breaking lap records. Still 1:38-1:39 is a fast enough pace.
Some may say that "understeer?" make the front soft. Well that was not possible because making the front soft was not good for the fast corners and I am not sure it would have helped in the 45-50mph corners.
Here is where the surreal experience started.
Toward the end of the day I could not just know that I have a brand new sticker Cup2 sitting there and not give it a try. I mounted the Cup2 to just see what its like.
The front grip was out of this world. I just turned the wheel and the car front went exactly where I wanted it to go. It had so much grip that the car was oversteering like crazy.
To make a long story shorter, I had to add Front HS +1, took the rear -1 on rebound, took the rear HS to 6 from 16 (6 is my comfort road settings) and that stabilized the car at 1:40 pace.
The ease and the relaxed way the car was doing 1:40 was so strange. I was not going fast on the straight at all, mild braking, and the car was doing 1:40 like it was nothing.
Now there is economic downside to this experience. Even at the slow pace of 1:40 the amount of rubber that came off the Cup2s was astonishing. I am glad I only tried this end of the day.
So there you have it, while Cup2 has great grip, it and the R7/A7 and the Corsa 60 tread are all great tires on the front, but not possible to use unless you own a tire company.
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