Tire choices for ZR1s - F-Body Road Racing and Autocross Forums

QUOTE

You're probably not going to like this one, but another VERY good choice for your 17x11 rims and intended use would be the Kumho Ecsta MX in 285/40-17. It's going to look more like a Formula One or GT race tire instead of a fat drag tire, but it's still a lot of rubber. It will probably handle better than the 315 Sumitomo and outperform it in the rain too. It certainly won't tramline as bad as the 315s. AND, it's cheap!

I saw this post in another thread, and it got me thinking: would 285/40-17 Kumho MX be a good choice for 17x9.5/17x11 afs zr1 combo? I like 315s on the back, but the tire selection sucks (especially considering the price). So would it be possible to put the 285/40/17s on both the front 9.5s and rear 11s (pics anyone?) and actually keep it balanced and safe to use in track situations? what's the point of the wider wheel then?

It's a strange, un-happy middle for me, as I would have the weight of the big wheel, but the grip of the smaller wheel. So I either go to 17x9.5s everywhere, or bite the bullet and pay a grand for a set of KD's and be done?

Please enlight me.
Dazed and Confused,
Marcin

RedHardSupra View Member Profile	May 14 2004, 01:27 PM Post #1
Advanced Member Group: Advanced Members Posts: 452 Joined: 12-January 04 From: Charleston, SC Member No.: 121	QUOTE You're probably not going to like this one, but another VERY good choice for your 17x11 rims and intended use would be the Kumho Ecsta MX in 285/40-17. It's going to look more like a Formula One or GT race tire instead of a fat drag tire, but it's still a lot of rubber. It will probably handle better than the 315 Sumitomo and outperform it in the rain too. It certainly won't tramline as bad as the 315s. AND, it's cheap! I saw this post in another thread, and it got me thinking: would 285/40-17 Kumho MX be a good choice for 17x9.5/17x11 afs zr1 combo? I like 315s on the back, but the tire selection sucks (especially considering the price). So would it be possible to put the 285/40/17s on both the front 9.5s and rear 11s (pics anyone?) and actually keep it balanced and safe to use in track situations? what's the point of the wider wheel then? It's a strange, un-happy middle for me, as I would have the weight of the big wheel, but the grip of the smaller wheel. So I either go to 17x9.5s everywhere, or bite the bullet and pay a grand for a set of KD's and be done? Please enlight me. Dazed and Confused, Marcin

RedHardSupra View Member Profile	May 14 2004, 02:34 PM Post #2
Advanced Member Group: Advanced Members Posts: 452 Joined: 12-January 04 From: Charleston, SC Member No.: 121	OK, how about 275 front, 285 rear then? In general though, is there a rule of thumb/formula/whatever to tell us whether we're gonna get under/oversteer based on tire sizes, assuming the rest is constant? I would guess that the under/oversteer characteristics would depend on the slip curves of fronts vs rears. The closer the curves would be, the more neutral the car would be. Weight distribution (dynamic), would probably have something to do with it too, as I've seen cars that can show under or oversteer depending on how hard you're changing speed (aka large weight transfers, affecting weight distribution, thus forces on individual wheels, thus cornering force, thus slip angle). Am I even on the right page here?