[pelicanruck]

99 Cobra. I know,, its been covered about 500 times b/c thats what my search turned up,, but I dont quite get it. Whatever,, "a retard humping a door knob".. My car has 17x9 rims on the front with 255/45/17. Which I've read is too big (might be 9.5, will pull the wheel this weekend and confirm). I bought it that way. Its lowered, @ 26" to the top of the wheel weel which i believe means about an inch. From what I've read, you cant go much narrower on a 9" rim than a 245. I was going to go with a 245/40/17 as of yesterday, but the guy i talked to this morning said stock was 245/45 and going to 40 might cause problems.. But it was my understanding that a 40 was 5mm smaller in diameter,so why would that cause problems. Ii just really don't want to buy tires and have them rub anyway, but i like the look of the ride height and would prefer not to go back to stock springs either. People also say its not just the size, but the brand.. Through in caster camber plate adjustments and i through my hands up.. I would really prefer to buy tires with some hope or authority that they are going to fit.. I know nobody can say for sure, but anything will help. Any measurements im not giving that i should be?.. Oh, its rubbing the inside edge of the wheel weel on the left side only, seems to be 1/4" difference between the left and right side, i dont quite get that either.

[Jobra]

To be honest I think you would be safe with 245/45/17's. If it rubbing on the inside that usually the first number (245/255/etc) that is too large/wide. Anyone else have input?

[pelicanruck]

Thats what i am thinking, but to add to my confusion i just read a 17x9 requires a 275/45 for a proper fit.. ugh.. I will take some pics to show whats going on.. Its rubbing in turns. I will take the wheel off this weekend and make sure its only rubbing there. Are there any sort of spacers available.. im sure 1/4" would do it.. just dont know a lot about lowered suspension.

[scount757]

If this helps, i have a 99 Cobra lowered about an inch and a half with 04 wheels and 275s. I am nowhere close to even a fathom of a rub

[pelicanruck]

Well tonight, I turned in increments lock to lock and couldn't find the inside lip rub. I can see where its rubbed off the paint, so maybe its having weight on board causing the rubbing.But sitting in the car not moving lock to lock its not hitting, while i was sitting in with pops watching.. Im left to pulling the wheel off sat. and looking for other places its hitting. Just uber stumped at this point.

[Kimo]

Originally Posted by pelicanruck Thats what i am thinking, but to add to my confusion i just read a 17x9 requires a 275/45 for a proper fit.. ugh.. I will take some pics to show whats going on.. Its rubbing in turns. I will take the wheel off this weekend and make sure its only rubbing there. Are there any sort of spacers available.. im sure 1/4" would do it.. just dont know a lot about lowered suspension.

First thing you need to find out is the offset of the wheel- and find out if it is in fact a 9 or a 9.5 etc- I can help you find the right size- I am a Manager for Discount Tire co. We do have locations in Fl but not sure if any are near you.

Also take a picture of the current fitment-! Thanks!

[Kimo]

Don't worry man, its a simple issue!!! We can get it!

[RC04SVT]

275 should be no problem in the front

[svtcobra041]

Stock rim size is a 17x8 with a 245/45/17 on all 4 corners. I have an 01 cobra with the 04 cobra wheel 17x9 and i am using the 275/40/17 which is the factory size for them. When i turn to the locks mine hits the wheel well which is only done when making a very tight low speed turn other that that no issues. a 255 will also work on a 17x9. You didnt say what wheels you had on your car.

[2003MACHWON]

i have a mach 1 which yall know is lowered an inch lower that a standard gt. im running 17x9 on front and 17x10.5 on back im running 275/45/17 and back is 315/35/17 i personally with your set up being 17x9 would go with 275/45. if you had the stock wheel (which is a 17x8) you would run a 245 tire. and you shouldnt have any problems with rubbing..

[ReverendDexter]

I ran 275s on a 17x9 on the front of my Cobra with no rub.

It really depends on the backspacing of your wheel. Mustangs don't like much more than about 6" of backspacing. When I put my 17x9s on my fox, I had to get 1/4" spacers because the backspacing was wrong.

Now, for the size issue, I've found 255s to be just right on 9s. Gotta remember, the factory specs fairly wide tires for the size of wheel because that gives less NVH.

[Kimo]

Again the offset of the wheel is going to be key here!

[ReverendDexter]

Originally Posted by Kimo Again the offset of the wheel is going to be key here!

And offset is just a different way of expressing backspacing. I prefer the backspacing measurement because it's consistent between wheel widths - a 4.5" backspace wheel has 4.5" of backspacing whether it's a 6" wheel or a 10.5" wheel.

[Thumbie]

I had 245/45/r17 on all 4 corners no issues

[ReverendDexter]

Originally Posted by Thumbie I had 245/45/r17 on all 4 corners no issues

I would hope not; that's the stock tire size, lol.

[Kimo]

Originally Posted by ReverendDexter And offset is just a different way of expressing backspacing. I prefer the backspacing measurement because it's consistent between wheel widths - a 4.5" backspace wheel has 4.5" of backspacing whether it's a 6" wheel or a 10.5" wheel.

Yeah seems easier to explain- i just wanted to know his offset so i could determine if that had anything to do with it! I get mustang owners with FWD wheels all the time in here hahaha

[pelicanruck]

Ok,, I'm back after an extensive of southeast Asia and the southern continent. But seriously, sorry for the delay.. Everything i try to upload fails.... Again,, just dummy.. Tried gif, tiff, whatever, jpeg was not even readable at the size it needed to be. . I will work on that part.. But for the wheels, some more relevant info. the wheels are 17x10 measuring the entire width. I realized that the lip didnt count in the rim diameter, but measuring the width they measure 10' from edge to edge. . Backspace is 6".. And i am beginning to think its b/c im fat that it rubs b/c its only on the drive side, but it rubs on my wife too, and shes only,, well,, that would never be quite proper so over 100 and under 150.. will get the picks as soon as i figure it out,, will pm to anyone who wants them..

[pelicanruck]

Giving up on photos.. both my pdf and gif are under file size and dims and it fails. thanks for all the help though. Its pretty cool to have a support group for mustangs.. Its like MA or something.

[pelicanruck]

Just been rereading more of whatever i could find. If 6" backspacing is considered the high side, could it be the combination of the 10" wide rim and the 6" backspacing. Obviously, i can only add to the backspacing. Its only rubbing during turning slow. But its rubbing quite a bit and not close to the lock. Not much radius at all.. Only hits turning to the right. Is it possible going to a 40 would help". I don't see what width has to so with hitting during a turn. I can see how backspacing would effect it, but then im looking at buying new rims. Something is going on. People are running wider tire with no issue. What is the stock wheel well height, or bumper, or what should i be measuring to confirm how much lower the car is, and what would the stock # be. Because its only one side, could it be a camber/ camber issue, i dont see how camber coudl be it,, but since its only rubbing on the rear edge , could it be caster? A caster adjustment. I really need to get the picks up.

[ReverendDexter]

I'm guessing that your wheel is actually a 9".



You could try a 1/4" spacer - AM sells some cheap ones for $15 if you don't have any you can borrow, though if that works I recommend buying the $50 MM units as they're MUCH better.