Let's get serious about track tires for GT350

[JAJ]

Because I started with 4 track days on the 285 Pirelli's, I realized that I'd eventually run out of fronts before I ran out of rears, so to let the rear 325's "catch up" with the fronts, I stuck a set of Michelin MPSC2's in 315/30x19 (GT350R rear tires) on the front of my GT350 - I was running staggered 315F/325R. I ran this for four track days. Here's what the MPSC2's looked like after 1 day on the rear of the car last year and 4 days on the front this year:

They took surprisingly little wear as front tires, especially when you compare them to the "matching" MPSC2 305/30x19's they ran the single track day with last year:

So, let's see, the 315's with 5 track days look about as worn as the 305's with 1 outing.

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[JAJ]

I figured I'd be through the Pirelli's and the Michelins this year - I'm probably going to get to around 15 track days before October. The thing is, I'm at 9 and the Pirelli's are still working just fine, and I'm probably good for four more outings on the Michelins before they're done. That means I won't get to try these big guys out until next year:

The thing that blows me away is that the GY's have the same groove depth as the thoroughly used Pirelli's and Michelins. It'll be interesting to see how long they last once I get through all the rest of the tire inventory.

 

[JAJ]

So, what's the summary of all this?

1. Pirelli Trofeo R's are really grippy and really durable.

2. Michelin 315/30x19 MPSC2's are a better front tire than the 305/30x19 that's supposed to go up front. Lots of grip, last better too.

 

[firestarter2]

So, what's the summary of all this?

1. Pirelli Trofeo R's are really grippy and really durable.

2. Michelin 315/30x19 MPSC2's are a better front tire than the 305/30x19 that's supposed to go up front. Lots of grip, last better too.

Well my PSC2 have tread but no grip

So, what's the summary of all this?

1. Pirelli Trofeo R's are really grippy and really durable.

2. Michelin 315/30x19 MPSC2's are a better front tire than the 305/30x19 that's supposed to go up front. Lots of grip, last better too.

How were your times with different tires and level of grip you may ended up under driving the tires so they lasted longer than they would of with matching sets.

 

[JAJ]

Well my PSC2 have tread but no grip

How were your times with different tires and level of grip you may ended up under driving the tires so they lasted longer than they would of with matching sets.

What I'm showing is what I have - it wasn't intended to be an endurance test or anything else - it just ended up looking like it.

I'm going to run the Trofeo's until they cord or they run out of grip. At this point, they don't owe me anything.

As for Michelins, I got six track days out of my last set of 305/315 MPSC2's - the fronts were done and one of the rears got damaged, so that was the end of them. The current set is "partially used" and I don't know what to expect. The fronts have 1 day, so I might get 4 or 5 more days. They'll run with the 315 rears, currently with 5 days, so that'll put the rears up around 9 or 10. Who knows if they'll last that long - I won't know until I get there.

The confounding issue on these tire sets is that the suspension setup was a work in progress this year. I installed R front springs, an R rear sway bar and R shocks in my GT350 near the end of the season last year. I'm running a DSC Sport magride controller, so i started this year with the goal of setting the car up to maximize driver confidence in the corners, and that means that for the first seven days out this year, the shock settings were different from session to session and day to day. By the time I got to days #8 and #9, I had settings I liked and I ran the 315/325 tire set for #8 and then switched back to the 285/325 set for #9. The differences in cornering speeds were minimal, within one or two MPH, with slightly higher speeds in fast corners with the 315/325 setup and slightly faster speeds in slower corners with the 285/325 combo. My lap times aren't relevant to this discussion - I just don't see the point in wringing the car out on the straights, so I don't. I find my fun in the corners.

 

[MikeR397]

I chord my cup 2 fronts in 4-5 track days with 3 degrees negative camber. The rears heat cycled out on me on the 8th or 9th track day, about 50% tread left but car was sliding around horribly. Put my spare rear wheels on at track day and 100% fixed.

 

[svttim]

I will buy used slicks. 600 a set is an easy deal. I have used tire conditioner in the past with good luck for heat cycled tires

 

[firestarter2]

I chord my cup 2 fronts in 4-5 track days with 3 degrees negative camber. The rears heat cycled out on me on the 8th or 9th track day, about 50% tread left but car was sliding around horribly. Put my spare rear wheels on at track day and 100% fixed.

I rotate mine so I got 8 I think

 

[JAJ]

I will buy used slicks. 600 a set is an easy deal. I have used tire conditioner in the past with good luck for heat cycled tires

What's the story on the new Shelby branded tires? They looked interesting - I think you posted about them a while back.

 

[1mic]

Weight of the tires would help too. So far I think michelins are typically the heavier tires out of all the brands, even in slick form.

I believe the pirelli slicks may be the lightest. But I dont know how long they will last.

 

[svttim]

What's the story on the new Shelby branded tires? They looked interesting - I think you posted about them a while back.

apparently the tariffs have screwed things up. :(

 

[honeybadger]

I will buy used slicks. 600 a set is an easy deal. I have used tire conditioner in the past with good luck for heat cycled tires

Which slicks are you thinking?

 

[arsenalrocks]

if you want a longer lasting track tire, forget about the original cup 2, you would have to get the Porsche spec with higher load rating. it is slower than the OEM cup2 but lasts at least 2x as long. all the fast guys with GT350 on my track without exceptions, run the Porsche spec.
it will be interesting to see the comparison between the new FP spec cup 2 vs. Porsche spec cup 2.

 

[TDC]

if you want a longer lasting track tire, forget about the original cup 2, you would have to get the Porsche spec with higher load rating. it is slower than the OEM cup2 but lasts at least 2x as long. all the fast guys with GT350 on my track without exceptions, run the Porsche spec.
it will be interesting to see the comparison between the new FP spec cup 2 vs. Porsche spec cup 2.

Do the Porsche spec tram line as badly as the Ford spec?

 

[honeybadger]

if you want a longer lasting track tire, forget about the original cup 2, you would have to get the Porsche spec with higher load rating. it is slower than the OEM cup2 but lasts at least 2x as long. all the fast guys with GT350 on my track without exceptions, run the Porsche spec.
it will be interesting to see the comparison between the new FP spec cup 2 vs. Porsche spec cup 2.

They do seem to heat cycle out on aggressive drivers, though. Perfect street/track tire IMHO, however.

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