One more track day?

[smokinscooters]

I did a track day yesterday and thinly my front Cup 2s may be toast. I'm relatively new to track days and am running in the intermediate group. These fronts look like they're done to me but wanted to get input from those who have much more experience than I do on the track? Do these need to be replaced or do you think o Dan get one more track day out of them?

Also, I'm at -2.6 camber on the front. Looks like I need to go up to -3.5, as the outside of the fronts wore much more quickly than the inside of the tire? Any recommendations for camber for the track?

 

[bpracer]

Mr. Fair would tell you need all the camber you can get.

BTW, we live in the same city.

 

[smokinscooters]

@bpracer - what tracks are you running, MSR Cresson and Eagles Canyon? Let me know next time you go. Would love to meet someone local.

 

[Bill Pemberton]

Hard to tell from your picture, though you do have that faint looking stripe going around the middle. Is that actually showing cord or just an oddity in the photo? I ran my Cups down more than that but I did have my camber at -2.8. Not much more but I was getting pretty good tire wear at that. You can take Cup 2s down quite a bit , but a bit more negative camber can't hurt. I ran the rears at -1.9 and that worked really well!

 

[smokinscooters]

@Bill Pemberton - thanks for your input. No cord, just an oddity in the picture. Thanks for the input on front/rear camber. Is there a camber plate that you would recommend that would allow me to adjust between street and track alignments? I daily my GT350 and don't want to go so aggressive on front camber that I'm wearing out the inside of the tires on the street. Thanks for your input.

 

[honeybadger]

I did a track day yesterday and thinly my front Cup 2s may be toast. I'm relatively new to track days and am running in the intermediate group. These fronts look like they're done to me but wanted to get input from those who have much more experience than I do on the track? Do these need to be replaced or do you think o Dan get one more track day out of them?

Also, I'm at -2.6 camber on the front. Looks like I need to go up to -3.5, as the outside of the fronts wore much more quickly than the inside of the tire? Any recommendations for camber for the track?

View attachment 98398

THis looks like its starting to chunk to me. I think you're done with this set



What hot pressures were you running?

 

[smokinscooters]

Hot pressures were 35-36.

 

[honeybadger]

Hot pressures were 35-36.

that's a bit warm (especially if they peak above that for any length of time) - drop down to 32-33 and that should help wear in the middle.

IME, Cup2s were VERY sensitive to heat (they chunked in the middle if you ran too high for any period of time)

 

[smokinscooters]

My cold pressures started at 28. Should I be starting with lower cold pressures or just bleeding air out in between sessions to maintain a reasonable max hot pressure? Thanks for your input.

 

[honeybadger]

My cold pressures started at 28. Should I be starting with lower cold pressures or just bleeding air out in between sessions to maintain a reasonable max hot pressure? Thanks for your input.

depends on the ambient temp and track, but absolutely can go lower. I frequently started Cup2s at 25/26 at COTA during "warm" months and during a properly hot day, I've been as low as 23 going out for the first session.

 

[dragoon]

Wait, what ??
You 2 doing hot tires here & hot oil on m6g ????????

 

[bpracer]

@Bill Pemberton - thanks for your input. No cord, just an oddity in the picture. Thanks for the input on front/rear camber. Is there a camber plate that you would recommend that would allow me to adjust between street and track alignments? I daily my GT350 and don't want to go so aggressive on front camber that I'm wearing out the inside of the tires on the street. Thanks for your input.

If you set the front up with a modest amount of camber (-1?) with the smallest amount of toe-in you can measure as your street setup, then just max out the camber for your track day. Don’t touch the toe when you change to max camber. The track camber change will get you a bit of toe-out, which is not a bad thing.

Over -2.0 degrees of camber and SC2s makes for very darty car on Dallas highways.

Vorshlag is the top of the line camber plate and they are made locally, Princeton TX. My black ‘16 GT350 is probably still pictured in their install instructions.

I’ve sort of been out a track stuff since Covid, but I’m about to retire and will restart things. I used to instruct a little at ECR, but my background is vintage racing a 65 Mustang. I will either modify my GT350 more, or buy a purpose built racecar.

As others said, SC2s don’t need a lot of air pressure. I think I ran 28 cold. 32-33 hot

 

[JAJ]

And then there's this section on page 39 of the 2020 GT350 Owner's Supplement:

 

[smokinscooters]

@honeybadger - Hey Kevin, last time that I bug you on this topic. I got the wheels/tires off the car and got better pics of the top. They look like they're structurally fine but there is some slight chunking in the center of the tire. I think you are correct that I was running hot pressures too high, as it's only the center of the tires that experienced the issue. After reviewing the latest pictures, do you still think these tires are done? I definitely want to err on the side of caution and pick up new ones if these aren't safe.

 

[smokinscooters]

And then there's this section on page 39 of the 2020 GT350 Owner's Supplement:

View attachment 98416

I wouldn't use this as a guide. This is what I was running and it chunked the center of the tires.

 

[honeybadger]

@honeybadger - Hey Kevin, last time that I bug you on this topic. I got the wheels/tires off the car and got better pics of the top. They look like they're structurally fine but there is some slight chunking in the center of the tire. I think you are correct that I was running hot pressures too high, as it's only the center of the tires that experienced the issue. After reviewing the latest pictures, do you still think these tires are done? I definitely want to err on the side of caution and pick up new ones if these aren't safe.

View attachment 98413

View attachment 98414

Yeah - i'd consider those done. They might have a session or two left in them - but definitely not an entire day

 

[TMSBOSS]

Would I run these tires? Yes…..but. I would have a second set on hand and check after each session.
If I had budget, likely no.
Do you trailer to and from the track?

 

[EF1]

Would I run these tires? Yes…..but. I would have a second set on hand and check after each session.
If I had budget, likely no.
Do you trailer to and from the track?

 

[smokinscooters]

I drive to the track. Unfortunately, I do not have a trailer.

 

[EF1]

Then replace them if you do not have a spare set waiting in the paddock to get you home.