What size tire can I run with my IRS??

[stangman1]

Ok guys I am wondering if I can get a 28x10 1/2 tire under my 03 Cobra or not. It has the complete full tilt boogie kit in the IRS. I am wanting to order a set of the ET Street Radial Pro tires & was curious if they might fit. My car also has a set of Steeda lowering springs on it as well... Any input would be appreciated.

 

[Avispa]

A lot of us are running 315/35/17s on 17X10.5 wheels. Those will just touch the bolt that holds up the back of the IRS subframe. Not sure how much more you can fit in; maybe another 1/2 inch with spacers or different back spacing wheels.

 

[Stage 4.6]

I run a 315-35-18 on 18x10.5 AFS wheels on mine but it is extremely close to the top irs bolt, I have to be very careful on dips. I am actually going to 305s possibly 295s don't want to take the risk of hitting a dip at speeds and blowing a tire.

 

[Patriot Guy]

Have been running 295/35 - 18s for years on the 18-10.5 AFS
and no bolt issues at all.

 

[Jduane]

im running 315-35 et street radials on 17x10.5 cobra wheels and installed the irs frame bolt kit from American Muscle and have NO Issues. car is also dropped on H&R Race Springs.:rockon:

 

[Stage 4.6]

im running 315-35 et street radials on 17x10.5 cobra wheels and installed the irs frame bolt kit from American Muscle and have NO Issues. car is also dropped on H&R Race Springs.:rockon:

I can probably get away with the 295-35s on mine and not hurt anything, mine is dropped with H&R springs as well, but I like the look of the big tire in the rear. How hard is it to replace that irs frame bolt.

 

[AMDanBailer]

Ok guys I am wondering if I can get a 28x10 1/2 tire under my 03 Cobra or not. It has the complete full tilt boogie kit in the IRS. I am wanting to order a set of the ET Street Radial Pro tires & was curious if they might fit. My car also has a set of Steeda lowering springs on it as well... Any input would be appreciated.

Hey,

That is one beefy tire, and it will be close to whether or not it fits.

We guarantee a 325/45/17 on one of our wheels, to fit on the back of those even if you are dropped up to 2". On the Cobra you will need the low profile IRS bolts, but other than that, you shouldn't have any issues.

A lot will depend on the wheel you are using, our wheel has a 27mm offset, so if you are around that or have that exact offset, you should be good to run that wheel without a problem.

I hope this helps, and if you have any questions, feel free to get in touch. Good luck!

-Dan

 

[BMR Tech]

http://www.svtperformance.com/forum...1002210-can-i-run-28x-10-1-2-tire-my-irs.html

 

[MBoyle1]

I run a26x11.5x16 & have lots of room may try the 28s next

 

[Avispa]

How hard is it to replace that irs frame bolt.

Total piece of cake. Shouldn't take you ten minutes more than it takes to jack up the car and remove and replace the rear wheels. Jack up the car and replace the bolts one side at a time so the IRS subframe will more or less stay in place and keep the bolt holes lined up.

 

[FromGTtoSVT]

Total piece of cake. Shouldn't take you ten minutes more than it takes to jack up the car and remove and replace the rear wheels. Jack up the car and replace the bolts one side at a time so the IRS subframe will more or less stay in place and keep the bolt holes lined up.

good to know, thanks...i just ordered a set of the low pro bolts. Was curious how much of a pain it was. Sounds easy:beer:

 

[Avispa]

And yes you DO need the low profile bolts with the tire/wheel combo I'm running. Had the back wheels off for a rebalance two weeks ago and saw some small shiny spots on the bolt heads (and these are the low profile bolts).