Tire questions

[Stevo]

Hi all. I'm new to Autocross and have attended a couple of events. I'm starting to consider tires because the stock rubber is almost five years old and will need replacing soon. Stock rubber on my 07 Shelby GT are BFGoodrich g-force T/A KDWS 235/50ZR18. I'd like to consider a couple options. First a summer tire, maybe shaved but State Inspection friendly. Second option, new rims and dedicated solo tires.

The car is used primarily between mid April and the end of October; maybe 3,500-4,000 miles per year. I'd like to maintain my F-Stock classification which, if I understand correctly, is any tire that can fit on the stock rims (or new rims with same size and offset)

Any advice would be greatly appreciated.

[newportroyal]

With any of the tires that you'll be able to choose from, shaving will probably not do anything beneficial.  From what I've seen, shaving is really only beneficial on one size of Toyo R1R, and on the Hankook R-S3's.  And the Hankooks supposedly get trashed quickly on heavy cars, so shaving is the last thing you'd want to do to that tire if you were going to use it on your car.

What you should also be considering besides brand and model, are size.  If you drive your car such a limited amount, I can't think of any reason why you wouldn't want to up the size - a lot.

What size are your wheels?

[Stevo]

Hi, thanks for the reply. I'm assuming the wheels are 8x18" I'd like to stay in my class 'F Stock' before I venture in to one of the performance classes. I have heard that I need to stay with stock wheels (or does the diameter have to remain the same?). If on the other hand the car is  more competitive with a larger wheels (with or without me.. ) then I might be interested in moving to a class with more cars. The tires you mentioned are examples of what I'm interested in; however, I dont see the exact size of 235/50ZR18 in either. Do you know the what the biggest tire is that those rims can support? more importantly, the biggest the Shelby GT can accept? The SGT is lowered 1.5" from a stock GT configuration.

Thanks again.

[Stevo]

sorry, the rims are acually 8.5x18" The guru at Tire Rack says that the biggest match is 255/45R18. Will those tires bump me out of F-Stock?.

Thanks again.

[Jenna]

Shaving the Hankooks did absolutely nothing for me.

In stock class, you can run any size tire, as long as it fits on the stock rim and you have clearance with no modifications, aside from a spacer that gives you a +/- 6mm offset from stock.

Tire rack has a widest width recommendation. If you can fit it on the wheel, and it will not have any clearance issues, have at it.

<--- runs 315's on a 18x8

[newportroyal]

I vote for 265/35/18 Dunlop *Specs

You'd only be a half inch out of the manufacturer recommended wheel width range so it wouldn't be too pinched, you wouldn't sacrifice much if any height, since I'm assuming you don't want to run a really short tire on that car.   

[pj]

I'm wondering where you heard the RS-3 gets trashed on a heavy car.... they seem to be holding up well on my 3350lbs car just fine.

[sivret]

I have to agree with Pj Dave and I have about 200+ runs and and about 5000 street mile on the rs3 on the stx car and the car is about 3200 lbs we just got a new set for the tour not because they are down to the cords but because we think we have heat cycled them out and feel there is just not enough stick left in them

[Stevo]

Thanks for all the advice everyone. Now I have to figure out which ones I can afford... 

[newportroyal]

I heard that they wear quickly on heavy MacPherson cars from a few different STU and STX people.

But considering your experiences, it looks like I might have to try the 'kooks.