Tire width for Cobra

[Cobra_Kai]

Hey guys -

Gonna start HPDE pretty soon here, and I am currently running with 10" wheels on rear and 8" on front. I have an extra PAIR of 8" rims, and I was going to buy another pair of 10" to make a complete 10" set - does anyone know if 10" wheels on the front will clear everything on my 1998 Mustang Cobra? Or will I just have to put them on this weekend and test them myself?

Also, since I am new to HPDE - I am assuming I should try and race with the widest tires my car will allow - correct?

 

Thanks guys!

Dan

[runningmole]

You'll probably need some fender modding to fit 10s up front. But I'm not positive.

 

I think it's better to start out on street tires. That way you can learn the limits of your car in a trim that you're familiar with (street trim) You'll also be impressed how much fun you can have on street tires. It may sound cocky, but I love getting by Porsches, Corvettes, BMWs, and other nice handling cars while on street tires. While Mustangs don't have the ride quality of those cars, it is fun to see if you can hang with them. Just something to consider

[Irish1]

I ran 255/40X17 Victoracers on 17X9 rims on my modded 99 Cobra, and it was a tiny bit undertired on track with the Shelby Club. I think 275/40X17s are a great choice: they'll mount OK on a 17X9 rim, and not require a K-member change or too much negative camber to work fine. Also fit in the wheel wells OK, at least on a 99+. I think the temptation to run huge tires on a street car used on track occasionally is a bad idea: it messes up suspension geometry, wears hubs out and zaps the fuel mileage. I think 255s or 275s are plenty big enough. You might jump over to Corner-Carvers.net and do a search on tire size there. Do NOT just post a naive question about tire size without doing a detailed search. Corner-Carvers is a serious forum full of engineers and racers and they can get brutal if you don't do your homework. It IS a great source for Mustang technical and racing information.

[Cobra_Kai]

I think 275/40X17s are a great choice: they'll mount OK on a 17X9 rim, and not require a K-member change or too much negative camber to work fine.

Ok - as far as I know, I currently have 275/40/17s on the rear, but I think that is a 10" rim. So, my goal was just to move those rims to the front and buy another pair of 10" rims for the back - that is what I am trying to figure out. So a 275 will fit on a 9" and 10" rim?

 

Dan

[white_2kgt]

So a 275 will fit on a 9" and 10" rim?

 

Dan

 

depends on the tire manufacture. Tire width's vary GREATLY. My Toyo RA1's are 275's and they fit great on a 9" wheel, I probably couldn't get them on a 10" wheel if I tried. OTOH I also have a set of hoohoo's in 275 and it is going to be a VERY tight fit to get them on a 9" wheel, they were made for 9.5-10" wheels.

 

You will be MUCH better off in the long run to get a set of dedicated 9" wheels NOW, 4 of them, put a decent tire on them (assuming you have zero to little track experience) then at a later date throw some 'R' compounds on there. This will save your street tires and keep your pimp 10" wheels looking pretty (brake dust can be a bitch to clean off).

 

Also, I doubt you'd get a 10" wheel/tire combo under the front of your 98 cobra w/o some suspension changes and for sure a fender roll.

[Cobra_Kai]

You will be MUCH better off in the long run to get a set of dedicated 9" wheels NOW

Interesting...well, the 10" rims that I have are considered my "extra" pair, so I really dont want to go out and get a new set of 9" rims. SO, what it sounds like I need to do is run my car with my original 245/45/17 on my 8" rims all the way around and not use my 10" rims. Then maybe next year I'll sell my pair of 10" rims and get a set of 9" rims to put my R-comp tires on. Hmmmm.