Chasseur

Been running my 2019 GT Premium on the track (Limerock Park, CT) and shredding the stock all seasons tires and keeping her rear end planted. Any insights on rear to front tire/rim sizes? Thanks all!

Bert

For the road track you want a "square" set-up (same tire on all four corners); basically the more tire on the front (and rear) the better. I think you can fit up to 305 tires, with the right wheels, if you are really getting in to the road track thing. These are fairly heavy cars and they need a lot of tire for the track. Wide and lightweight wheels are perhaps the biggest impact modification for a road track car, so before you buy new tires, now would be a good time to consider whether you want new wheels too.

If you don't want to buy wider wheels right now: find out how wide your current wheels are, then buy tires to fit correctly on those wheels. I don't know if your wheels are the same front and back right now, or if you have wider wheels on the back. DO NOT go with tires that are too wide for the wheels; they will handle like mush and you'll be paying extra for more rubber that is not helping. You can check tires on Tire Rack; look at the "specs" tab to find the "recommended rim width." You want your wheels to be at least the "measuring width" for the tire size that you are running.

And definitely get rid of the all season tires. You probably want an "extreme performance summer tire" ; assuming you don't want to go "all the way" and get a "streetable track tire"

Extreme Performance Summer Tires | Tire Rack

Streetable Track & Competition Tires | Tire Rack

houtex

Hm. I'm not disagreeing with ya, Bert, as meats is good in my book, but I've heard it said like a 285 in the back and a 255 in front is the better turning setup, like an Indy car or Formula 1 car is...? *dunno* I mean, that's what them Shelby GT500s run, and they ain't slouches on that kind of stuff... Point being that the smaller tire in front is a better turner, no matter what the sizes are...

Just curious as to your thoughts on that, thanks!

Bert

The serious road track guys run 305 or 315 tires all around on the S197's, and I assume the S550's are the same. Basically they try to get the widest tire that will fit and clear, on all 4. These cars tend to understeer at the limit (due to the weight and depending on set-up) and the wider tires in front help with that. Like the OP said, you would be amazed how these cars tear up the front tires on a road track.

I think the GT500's come with the staggered setup from the factory because they aren't really set up as serious road track cars. They are more like a street and drag setup. And on the street, with front tires wider than around 275 or so, tramlining and hydroplaning get pretty bad, so that might be why they put the narrower tires on the front; also on the street, even 275 tires feel a little "heavy" in the steering in parking lots and other slow/tight situations, so that might be another reason why they put 255's on the front.

Come to think of it, I can't remember seeing a "serious" GT500 road track car during my road track days, but I bet they would run a square setup, 305's if they have the money and inclination.

I think the Indy or Forumla 1 cars are a different animal; they have down force and other things going on that are very different and would affect the tire sizing; don't really know.

m05fastbackGT

Exactly spot on with the Shelby GT500 setup.. I started out with the very same GT500 staggered combo with 285/40/18's in the rear and 255/45/18's up front.. Eventually I made the switch by going with 275/40/18's on all 4 corners, as I much prefer to run a square setup in order to rotate tires.. Roush Performance also used the 275/40/18" square setup on their 18x10" wheel package w/45mm offset on the 2005-14 stage 3 Roush models.. Therefore, both of you are spot on lol.

houtex

Ah. I have been learned. So it's pretty good I have 275's all round and didn't go to that 255/285 combo then. Awesome. Thanks everyone!

m05fastbackGT

I had nothing personal against running the 255/285 combo.. I just prefer having the ability to rotate tires which does extend the tread life.. Pretty much about the only disadvantages I've experienced with 275's all around, is steering feel is just a bit heavier when making turns, but haven't noticed any real differences in tramlining between 255 and 275's up front.. As far as hydroplaning goes, I can't really comment one way or the other, as I don't take my car out in stormy/wet road conditions anyhow, therefore, for myself personally, it's a non-factor.

Overall, I've been very pleased with running 275's all around, as they provide much improved handling and stability, especially at the corners when driving under spirited conditions

Siber Express

Actually it is more than just width, it is type of tire more than anything. You have a performance orientated No season tire and need to get into something that is sticky and for cornering (Drag slicks are Sticky but only going in a straight line as well as other tires for drag racing).
I am running Staggered but I have a lighter front end with the V6 so I do not have the Plowing effects quite as bad as the GT does.
I do believe with the right tire and wheel combo you can run 305's on all 4 corners on the S550
From the 2019 option page in the order guide
That isn't getting into the GT350 and GT500 tires and wheel set ups

Bert

not sure if the PP2 had some modifications to the suspension or fenders to clear those tires, but I know it was possible to get 305's on all four corners on the standard S197 chassis if everything is just right (including front camber) so it's probably safe to assume that the same is do-able on the S197 correction: S550

but it's kinda looking like we are talking to ourselves at this point, the OP Chasseur hasn't been back

Siber Express

I know of 1 that they took the Stock wheels off and put them on the sons 08 GT and put a take off set of the PP2 wheels on no modifications.
He still might come back so we have covered our bases John