First Track Mods?

[RocketGuy3]

Why are you guys saying you shouldn't put 285s on a 9.5" wheel? I haven't checked specs on tirerack or anything in a while, but I could swear that was within the comfort zone for 9.5... thought you could go even wider if you wanted to deal with some bulge.

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[Norm Peterson]

The Michelin Pilot Super Sport?
http://www.tirerack.com/tires/tires.jsp?tireMake=Michelin&tireModel=Pilot+Super+Sport

300 AA sounds like a yellow flag is it one of those freak tires that grips great for the wear?

Two weeks ago yesterday mine were still reaching above 1.25g laterally at a track day (generally cool and cloudy). I've got datalogs with numbers at least as high as 1.34g from the first day of that two-track-day weekend. This being the 9th and 10th track days on them, plus something like 3000 street miles.


Norm

 

[Norm Peterson]

Why are you guys saying you shouldn't put 285s on a 9.5" wheel? I haven't checked specs on tirerack or anything in a while, but I could swear that was within the comfort zone for 9.5... thought you could go even wider if you wanted to deal with some bulge.

9.5" is a minimum fitment for 285/35's, so yes, it's within tire industry guidelines.

But keep in mind that those guidelines are intended for the average consumer who thinks that 0.5 lateral g is hard cornering. Comfort zone for those whose automotive interests run toward cruises, Cars&Coffee, shows, and probably drag racing is irrelevant for HPDE. Side note - I do know that some autocrossers will make similar tire to wheel fitments, but that is a consequence of autocross rules limiting the wheel width but not the tire size and people making the best of the situation.

On bulge: you get more bulge with the narrow-wheel fitment, bulge being defined as the amount that the tire hangs out past the wheel and is not as well supported by the wheel as it would be with a wider wheel.

You're far more likely to roll the outside shoulders under as the tire deforms laterally when the wheel is at or below "measuring width" than you are with wider wheel fitments, and cornering response will be "softer" and less precise with the narrower wheel assuming that all else is held constant.

Best picture of tire distortion in the corners I've ever seen, and it's with "measuring width" wheels at both ends. Look at the inboard wheels for comparison.

And one of my own from a few years ago (look at the way the right rear does not wrap uniformly around the outline of the wheel, and know that the rear tire pressure was up around 45 psi at the time).

Norm

 

[Norm Peterson]

From what I can gather, if you run the MPSS brand new and get them real hot for a while at the track, they can chunk. They have layered design, which gives them better traction later in their life, but it can chunk if you run them hard too soon.

Reports seem to indicate that If you put a bunch of heat cycles through them on the street first (maybe 2k-5k miles), and then start tracking them, the MPSS should be ok. They need to harden up a bit first.

Thanks for this detail.

I did have at least 1500 street miles on mine prior to taking them out on the track for the first time.


Norm

 

[stoli]

As [MENTION=11496]Budwise[/MENTION] and [MENTION=6743]Norm Peterson[/MENTION] said, don't hesitate on the MPSS tires. I've been running them for track days and have been very pleased with them. Even after 25 minute sessions at Sebring adhesion was still really good w/ambient in the mid 70s.

 

[BTM]

Sub'd

 

[umarov]

I just did my first HPDE this weekend. I will make a post about it soon.
I ran the car stock. Since it was my first time at the track, I started reaching limits of the tires by the end of the weekend as my skills progressed.
PZero's communicated very well to me that I was reaching to the limits to the grip. I pulled a little over 1 lateral G. In few corners I had a lot of oversteer, but other than that the car did really well. I was very happy with it.
In my thread I will post some pictures of the tires and how they are chunking. I lost about half of the tread.
As far as mods, I would recommend getting track focused brakes. Street brakes don't handle heat very well, they are designed to stop well when they are cold. PP brake pads did really well tbh. But they will wear out much quicker.
Tires... I don't really know. There are so many options and each of them have lots of pros and cons. I plan to get the Nitto NT555 G2. My car is a DD, so I need a tire that does well in the wet as well as perform well at the track. G2 have a good balance.
I experienced a lot of body roll, set of sway bars would be a really good mod as well .

 

[Stangman21]

Hi, thanks for opening this thread! I always wondered how to fix that hopping going on whenever I try to gun it on a hard turn or on the roundabouts in the freeways.

http://www.americanmuscle.com/bmr-irs-lockoutk-kit-black-1516.html

 

[Competition Orange]

I have no first hand experience on the MPSS chunking, just second hand from avid racer buddies.

I did run my 2012 Golf R street wheels at an autocross 1 time when it was raining, so I swapped off my slicks and ran my street set (course had dried when I finally ran). They performed pretty well, but understeered and were not up to a camber challenged, understeery car.

Other than the fact they aren't 200tw good (duh) I think they're the #1 tire for someone looking for a mainly street tire, with some mild autocross, or hpde work. Anything serious, and its the wrong tire, IMO.

https://www.google.com/search?q=michelin+pilot+super+sport+chunking&espv=2&biw=1366&bih=643&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiDqIi_wofMAhVhn4MKHb6DCuoQ_AUIBygC

 

[GT_Roadcourse_Newb]

Two weeks ago yesterday mine were still reaching above 1.25g laterally at a track day (generally cool and cloudy). I've got datalogs with numbers at least as high as 1.34g from the first day of that two-track-day weekend. This being the 9th and 10th track days on them, plus something like 3000 street miles.


Norm

Cant wait to try them

 

[Norm Peterson]

I guess the tip here is to get some street miles on them first.

And when you're at the track, try to avoid parking on dirt or driving through any gravel. Even though they're 300TW street tires, they do get soft and sticky during a session and they will pick up lots of pebbles (which can then get embedded in the tread). Better to avoid picking up any more than can be helped, than count on your out lap to remove them all.


Norm

 

[GT_Roadcourse_Newb]

The unthinkable has happened guys!! Waaaaaaaah. http://www.mustang6g.com/forums/showthread.php?p=1212616#post1212616

 

[RocketGuy3]

I just did my first HPDE this weekend. I will make a post about it soon.
I ran the car stock. Since it was my first time at the track, I started reaching limits of the tires by the end of the weekend as my skills progressed.
PZero's communicated very well to me that I was reaching to the limits to the grip. I pulled a little over 1 lateral G. In few corners I had a lot of oversteer, but other than that the car did really well. I was very happy with it.
In my thread I will post some pictures of the tires and how they are chunking. I lost about half of the tread.
As far as mods, I would recommend getting track focused brakes. Street brakes don't handle heat very well, they are designed to stop well when they are cold. PP brake pads did really well tbh. But they will wear out much quicker.
Tires... I don't really know. There are so many options and each of them have lots of pros and cons. I plan to get the Nitto NT555 G2. My car is a DD, so I need a tire that does well in the wet as well as perform well at the track. G2 have a good balance.
I experienced a lot of body roll, set of sway bars would be a really good mod as well .

Oversteer? The car pushes like crazy in stock form. You can get the tail around if you get on the gas a little early, but I wouldn't think that's something your instructor would have you trying out your first time out...

 

[GT_Roadcourse_Newb]

I always thought the P-Zero's communicated very well. I can let you know how the BFG Comp 2's work after tomorrow.

They started talking, finally
Nice tires, actually!
Just need to anticipate a bit of slip last 1/3 of session. Which makes it even more interesting.

How were the BFG Comp 2's, Optimum Performance?

 

[tyshenry]

Just a quick data point about the RE-71Rs. Took them out tonight to MSR for a track night and they worked great. Yes they begin to fall off after about 12 min of hot laps but it wasn't terrible and was only costing me about a second. Still a second faster than PZeros. They were still predictable and overall felt good, just a decline in grip.

The tire itself held up well and wear looked pretty good. I'd recommend them.

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