Season starting soon, let's talk track tires.

[jmn444]

I'd like to learn so forgive me if this seems obvious but I do understand that the outside slits go before anything else. Wouldn't that mean that if rain is in the forecast for that day you have decision to make?

1) Either hope you got enough slits on the outside to be hauling ass in the rain and if you do hope that sun dries the track later in the session before the slits are gone.

or

2) Immediately switch to another wheel set like P4S and know it will be a 6/10 kind of day with rain...?

absolutely, i just use supersports if it's wet no matter what. I was mostly just saying that unless it's day one, the rain benefit is nil.

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[NoXiDe]

Here's a great question that I got to ask since we're sort of on this topic.

If most of the load is on the outside (inner) area why do we continue to see the inside of the tire corded first? I would have expected the opposite effect.

 

[jmn444]

Here's a great question that I got to ask since we're sort of on this topic.

If most of the load is on the outside (inner) area why do we continue to see the inside of the tire corded first? I would have expected the opposite effect.

toe out IMO.

My car likes a little toe in to save the tire.

Also possibly overdriving the car a bit, if you are pushing the front to slide into every turn, the inside tire is dragging on that inside edge too...

 

[torque124]

Here's a great question that I got to ask since we're sort of on this topic.

If most of the load is on the outside (inner) area why do we continue to see the inside of the tire corded first? I would have expected the opposite effect.

I never see inside of tire wearing out at the same rate as outside... look at my pics. That is with -2.2-2.3 camber front. Still wearing outside....

I suppose toe out will do that, as will too much negative camber.

 

[torque124]

I'd like to learn so forgive me if this seems obvious but I do understand that the outside slits go before anything else. Wouldn't that mean that if rain is in the forecast for that day you have decision to make?

1) Either hope you got enough slits on the outside to be hauling ass in the rain and if you do hope that sun dries the track later in the session before the slits are gone.

or

2) Immediately switch to another wheel set like P4S and know it will be a 6/10 kind of day with rain...?

Check the pic you posted... the wet traction is mostly ensured by the large inside grooves and slits, as per his explanation, not outside slits, which are very small anyway, and not very deep...

I was lucky thus far and only got dry days with the R, and I did 2 wet track days with my previous car, a non R track pack, but that had supersports on it. It actually behave really well to be honest on wet.

 

[NoXiDe]

I never see inside of tire wearing out at the same rate as outside... look at my pics. That is with -2.2-2.3 camber front. Still wearing outside....

I suppose toe out will do that, as will too much negative camber.

@torque124, I've been told the opposite. I've been told -3 is where the 350 likes to be. Unfortunately, it sounds like this is a topic (camber) where you'll just have to find out for yourself and adjust for next time. I will say yours looks great and I am actually at -2.2 but only because I think my camber bolt (BMR) needs to be readjusted. I'm maxed out on the Vorshlag plates already. I may stick with -2.2 unless @JAJ can convince me otherwise. ;) haha.

 

[JAJ]

@torque124, I've been told the opposite. I've been told -3 is where the 350 likes to be. Unfortunately, it sounds like this is a topic (camber) where you'll just have to find out for yourself and adjust for next time. I will say yours looks great and I am actually at -2.2 but only because I think my camber bolt (BMR) needs to be readjusted. I'm maxed out on the Vorshlag plates already. I may stick with -2.2 unless @JAJ can convince me otherwise. ;) haha.

I'm not going to try to convince anyone to go past -2.2 up front.

There's a thread on this forum from a year or two back about stiffness of wheels and how CF rims are much stiffer than aluminum, and that heavy aluminum wheels are stiffer than light aluminum wheels. Stiffness is not the same as strength. Forged is stronger than cast, but it bends the same under the same force.

Stiffness matters because when a wheel bends under lateral G's, it reduces the effective camber. So, if you're running lightweight aluminum wheels, you'll need more static camber than if you're running heavy aluminum wheels (like me) or CF rims. I run -2.2 and the tire temperatures look really good across the face of the tires. I'm happy with it.

 

[jmn444]

I actually think the cup 2's like less camber than tires that aren't diff compounds across the tire like they are. -2.2 probably would work well.

I like -3.2 as it seems to be a good balance between tire wear and being able to stay out of ABS. The tires I've been running would like a bit more, based on wear not on temps, but everything is a compromise.

 

[svttim]

Have you tracked the Goodyears? How are they compared to Michelins Sc 2 ?
I see them in 305 / 30/19 only on Tirerack, but that should work on all 4 corners, no? I know I won't be able to swap front and back as I track with the OEM carbon wheels, but should handle OK like that, no?
Also, there is a Supercar 3, and a Supercar3R, which is not rated yet on Tirerack... The 3R seems to be more of a slick than the 3, so more track oriented ? Which one?..


I am running that size 305/30/19 on all corners for street now on R spec size rims from Signature Wheels, they are fine.




Did you track the RE71s with oem carbon wheels? So it handled ok with 305 square; as above I am thinking of the Goodyears, I see they are available in 305.

Many thanks all.

The RE's were on a different wheel. Base GT350 size wheel

 

[JAJ]

JAJ how many days do you get out of Cup 2's (NOT the fp non R ones)?

anyone can answer this that has experience with them...

Just saw this question. I keep a fairly detailed tire log and I got about 30 heat cycles out of a pair of rear R spec MPSC2's, which took about 7 events. I kept running them until they were undriveable. I haven't finished a set of fronts yet - I've got a set with 29 heat cycles that were fine the last time out and I haven't decided if I'll trash them or run them once more just to see if they still work.

 

[jmn444]

Just saw this question. I keep a fairly detailed tire log and I got about 30 heat cycles out of a pair of rear R spec MPSC2's, which took about 7 events. I kept running them until they were undriveable. I haven't finished a set of fronts yet - I've got a set with 29 heat cycles that were fine the last time out and I haven't decided if I'll trash them or run them once more just to see if they still work.

7 days seems like a lot for them, that's cool!

 

[torque124]

Mine (pics in the first post) are at about 6k miles, and about 7 track days too... But some of my track days are only 1 hour of track time, so not that much driving.
I did do a Car control clinic and autocross at Lime Rock park in July last year (where they encourage you to drift/slide your car so you learn to control it when it's out of control ) , over 100 degrees F, I swear it looked like half of my thread was left there.

 

[webspoke]

I've switched from 305 RE71's square on stock sized wheels to SC3's on 11.5's square. The SC3 is a good tire, matched and beat my RE71 laps by a little bit, and they don't try to kill you in the first cold turns or get as greasy and loose later in the session.

Its a good tire, large for its size, almost 315'sh. Does not look stretched on an 11.5 wheel. Even thinking about using a 295 front on the old 10.5 wheels.

 

[jmn444]

I've switched from 305 RE71's square on stock sized wheels to SC3's on 11.5's square. The SC3 is a good tire, matched and beat my RE71 laps by a little bit, and they don't try to kill you in the first cold turns or get as greasy and loose later in the session.

Its a good tire, large for its size, almost 315'sh. Does not look stretched on an 11.5 wheel. Even thinking about using a 295 front on the old 10.5 wheels.

what offset and spacer size do you run on these? oem dampers?

 

[webspoke]

The wheels apex ET56 , with the long opm studs and 35mm spacers . OEM springs and dampers and controller, bmr front bar until 2weeks ago. Now bmr linear springs and bars front and rear. The damping still feels very good with the springs.

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