The Mustang Forum for Track Enthusiasts

Track Mustangs Online was built specifically for those who track their Mustangs!

Hoosiers on GT350R

Randy Marble

TMO Intermediate
This may have been discussed earlier, but I just may be too lazy to check.
Has anyone run Hoosier A7's on their GT350 / GT350R and if so, what sizes. Looks like there is a 315 /30 / 19, but nothing equivalent to the front 305's.
If anyone has experience with their car on the Cup 2's and then switched, would appreciate feedback, decreased lap times etc.
Thanks in advance.
 
I’ve run the 315s on 19x11in wheels. I felt like they were a bit wide for that wheel, but they worked great. The 295 is actually close to the factory 305, so that’s probably what I’d run unless I was chasing lap times.

The R7s are a great step up from the Cup2s - easy to get up to temps, last a bit longer, and are predictable. They ran 1.5-2.5 seconds faster a lap depending on the track.
 

Randy Marble

TMO Intermediate
Well, that is what I'm doing "chasing lap times". Just don't feel comfortable reducing the front size as there is 54% of the weight of the car on those. Wish Hoosier would realize the potential and make some 305's.
I can run very consistent lap times with the Cup 2's. Just looking to improve as I have kept the engine and drivetrain stock as I am after turn in and exit speed more than horsepower.
 

Randy Marble

TMO Intermediate
Well, that is what I'm doing "chasing lap times". Just don't feel comfortable reducing the front size as there is 54% of the weight of the car on those. Wish Hoosier would realize the potential and make some 305's.
I can run very consistent lap times with the Cup 2's. Just looking to improve as I have kept the engine and drivetrain stock as I am after turn in and exit speed more than horsepower.
P.S. Thanks for the reply
 

steveespo

Lord knows I'm a Voodoo Child
Moderator
3,641
996
NY Metro
And also. Any practical comparison between A7's and R7's. My car is for typical HPDE 25 minute sessions on road course.
R7 is a better long session tire, after 25 minutes the A7 may get overheated depending on the weather and track type. A7 is quicker, but has fewer good heat cycles and more wear than the R7. If you are racing or time trialing the A7 may be needed to be competitive, many of the fast cars in ST1/2 TT1/2 run the A7.
 

Randy Marble

TMO Intermediate
Thanks for all the advice. One more if you could. What would be the recommeded pressure be to start with? On the Sport Cup 2's, I find that they work the best hot at about 36 psi and they tend to grow about 8 pounds during a session so start them in the morning at 28. Any similar experience with the R7s?
Thanks in advance
 

steveespo

Lord knows I'm a Voodoo Child
Moderator
3,641
996
NY Metro
Thanks for all the advice. One more if you could. What would be the recommeded pressure be to start with? On the Sport Cup 2's, I find that they work the best hot at about 36 psi and they tend to grow about 8 pounds during a session so start them in the morning at 28. Any similar experience with the R7s?
Thanks in advance
Hoosier will tell you 40psi hot, but that is silly. Shoot for 30-31 hot but don't start below 25 cold, soft sidewalls can be easily damaged. Midway through first session or after warmup come in and check/bleed to 31 and work it from there. They are quick for 5-10 cycles especially if you are running square and can move tires from high wear to low wear positions after mid day. They will usually last 18-22 cycles before cording if you have proper toe and camber settings. This is for R7s, @ArizonaBOSS will have better info on A7s
 

ArizonaBOSS

Because racecar.
Moderator
8,473
2,249
Arizona, USA
Like @blacksheep-1 mentioned, A7s will be the quickest Hoosiers hands-down, but if you're not in a competition environment (especially one where you have an opportunity to take advantage of tire contingency), stick to the R7s. The As will cycle out before the weekend is over if you're using them for road-course duty, and on a heavier car you'll likely cord them quickly unless your setup is very well-dialed.
You should be able to get two full weekends out of R7s without issue.
 

Bill Pemberton

0ld Ford Automotive Racing Terror
5,026
3,413
Blair, Nebraska
W2W Racing
20+ Years
Blacksheep 1 and Arizona Boss are absolutely correct about the A7s , super fast on track , but so is their wear factor. I was getting 3 weekends at one of the tracks in our NASA Region on R7s because the track is so smooth. Even with smooth asphalt, many of the guys would destroy the A7s in a weekend. I had little chance of getting tires through contingency ( not enough in my Class many times ),so I switched brands for even more durability.
I don't think you will get anyone to disagree that the Hoosiers are the " Gold Standard " , but depending on your goals, whether you are running Time Trials or HPDEs , there are some other decent choices. The caveat , though, is none are likely to be quite as fast as the A7 or R7, though a couple are pretty close.
 

blacksheep-1

Epic Contributor
2,833
2,495
I run Pirelli take-offs at COTA and they're very, very quick. I get one good weekend out of them before they heat cycle out. Cost is about $600 a set on average
When Pirellis go, they really, really go, and I mean seconds per lap, although they are faster than Hoosiers, the Hoosiers are far more consistent. Since I've been messing with Michelins I think they may be the best of both worlds, they are consistently fast over a long period (first 4 laps don't count), however, I think we pay something like $2800 a set or some crazy price, so they should be the best.
 
When Pirellis go, they really, really go, and I mean seconds per lap, although they are faster than Hoosiers, the Hoosiers are far more consistent. Since I've been messing with Michelins I think they may be the best of both worlds, they are consistently fast over a long period (first 4 laps don't count), however, I think we pay something like $2800 a set or some crazy price, so they should be the best.
True that. 3-4 seconds slower a lap once they heat cycle
 

Bill Pemberton

0ld Ford Automotive Racing Terror
5,026
3,413
Blair, Nebraska
W2W Racing
20+ Years
And that can be an issue when you buy the Pirellis that were run in the World Challenge or another Series. Sometimes they have been heat cycled to death when you get them. Like BS1, the Michelins are the real ticket , but again , it depends if you are racing, doing Time Trials , or HPDEs. The Michelins and Pirellis will often bump you out of Class in Time Trials or W2W, so check your rules where you run.
 

TMO Supporting Vendors

Top