[dpevans]

I have a 2016 RS LGX M6. I retired full time last year and it has allowed me to start (road) tracking the car and did 4 times last year. I upgraded the pads with GLoc R8/10, stainless lines, and SRF fluid and change the fluids faithfully. I am not too serious just want to challenge myself and have fun and the LGX well suites my skill level of being a novice. I did want to step up my game a little this year so I purchased a set of stock 2021 SS rims, powder coated and have narrowed the rubber down to F1 SC3. question I have is 27.7 is the standard tire height of the SS and it seems you cannot get the stock sizes so the choice is 245/35/20 measuring 26.8 or 255/45/20 measuring 28 on the front the back go either 275/40/20 or 285/30/20. I do plan on changing the rear toe links to adjustable. I have heard for the track it is better to go to a smaller diameter tire not taller. Another question can you put the track alignment specs for the ZL1 on my car or is there a better spec? I plan on at least 6 sessions and will leave the tires on car for the summer. Any help for a track newbie is appreciated.

[Msquared]

Originally Posted by dpevans

I did want to step up my game a little this year so I purchased a set of stock 2021 SS rims, powder coated and have narrowed the rubber down to F1 SC3. question I have is 27.7 is the standard tire height of the SS and it seems you cannot get the stock sizes so the choice is 245/35/20 measuring 26.8 or 255/45/20 measuring 28 on the front the back go either 275/40/20 or 285/30/20. I do plan on changing the rear toe links to adjustable. I have heard for the track it is better to go to a smaller diameter tire not taller.

First, the 255/40/20 is 28" tall, whereas the 255/45/20 is 29.1" tall and should not be under consideration under any circumstances. I'm assuming that was just a typo, but I want to be sure.

Generally you don't want taller, right. It also doesn't generally pay to go wider on the same rim width. Among the SC3 size options for your wheels, I would probably go with 245/35/20 front and 285/30/20 rear. They are both 26.8" diameter, and are reasonable widths for your wheels. These are a good bit shorter than your stock tires or stock SS tires, but as a reference the stock tires on an SS 1LE are 26.8/27.2" diameters, so they aren't way short.

Another question can you put the track alignment specs for the ZL1 on my car or is there a better spec? I plan on at least 6 sessions and will leave the tires on car for the summer. Any help for a track newbie is appreciated.

The SC3s don't seem to love as much negative as some other track/competition tires, but I'd still shoot for -2.5 front and -2.0 rear, with zero toe front and a teeny bit (maybe 1/16") toe in rear. The rear camber is limited by the adjustment range of the toe link: after a certain amount of negative camber, you can't avoid toe out, and you definitely don't want toe out in the rear. However, you might actually not need the adjustable toe links to get that in back: I can get -1.9 on my SS 1LE with the stock links. That would be close enough.

[dpevans]

thanks Matt