Fox 17" Deep Dish Bullitts on Rear of Fox, 275/40/17?

[pindude80]

I bought a set of 4 OEM 17" Ford Bullitt wheels for my '88 GT. I was thinking of running the deep dish 10.5" Bullitts from LMR on the rear (link below) since someone screwed up the brushed lip on one of the wheels by sanding it.

I was planning on running 245s on the front and 275/ 40 r17 on the rear. Do you guys know if the 275 will be wide enough to go on the 10.5" wheel and also if 275s will clear the factory wheel opening without any issues? As far as I know the car has the factory Fox rear end in it. I cut 1.5 coils out of the factory rear springs. It does not have quad shocks. I do not plan on putting the quad shocks back on unless my wheel hop issue comes back. I am pretty sure the wheel hop issue I was having was caused by Toyo Proxes R1R tires that were on the car. I put the Bullitt wheels on with the woreout Firestones and the wheelhop went away.

https://lmr.com/item/LRS-1007SBA/1994-04-Mustang-Anthracite-Deep-Dish-Bullitt-Wheel-17x10-5

 

[gkomo]

That wheel has a pretty large positive offset. I wonder if you'll get significant rubbing on the inner fender due to the fox length axles being narrower than the 94+ length the wheels were designed for. I would assume a fender roll is in order as well for how wide that wheel is. No quad shock is probably a must so good thing you removed it, but i still think you'll get rubbing on the actual metal inner fender.

 

[Warhorse Racing]

Because of loose production tolerances, it’s hard for anyone to be 100% sure what will fit your specific car. Mods also make a big difference in how much room you have for wider wheels and tires. I highly recommend going to www.willtheyfit.com and comparing your new setup options to your existing setup. Use the info from that site to mock-up how the tires will fit on your car. Be sure to check both sides.

In general, a 275 will be stretched on a 10.5” wheel.

Here's more helpful info:

Keep in mind that, despite being listed as the same size, different brands of tires can vary in size. Look at the specs for the tires you’re considering on Tire Rack. Find the Rim Width Range & the Measuring Rim Width. The MRW will let you know if the tire you want will be pinched or stretched on your wheels. There are advantages and disadvantages to pinching or stretching. You should also compare the Overall Tire Diameter to the tires you have now.

It’s worth mentioning that using staggered wheels and tires will add understeer. If you haven’t made other mods to compensate for the added understeer, it’s something to be aware of if you plan on using the car for performance driving.

 

[Noobz347]

It’s worth mentioning that using staggered wheels and tires will add understeer. If you haven’t made other mods to compensate for the added understeer, it’s something to be aware of if you plan on using the car for performance driving.

How significant is this increase in the real world?

What I mean is: An 8" wide tire in front and a 10" in the rear seems like it would add [less] understeer than rebuilding a worn out traction lock. Do you consider this to be correct or will this kind of stagger have more effect than I think it would?

Now, skinnys... Never on the street IMO and dangerous for a [lot] of reasons.

 

[pindude80]

I would rather not try to roll the fenders or beat on the inner wheel well. I wonder if the better move is to run 275/40r17 on the OEM wheel? I'll have to do a little research to make sure a 275/40r17 will fit on the OEM wheel.

 

[Noobz347]

It is not very often that a 275 will fit in the rear without having to clearance [something].

 

[gkomo]

Not apples to apples, but i run a 274/40/17 on an 8" wheel (sn95 length axles), i had to roll my fenders (maybe something you wouldn't have to worry about with the narrower fox length axles), and i also get slight rubbing on my inner fender at some odd angles, like going up a steep driveway at an angle. They are just big tires for the Fox wheel wells whatever way you slice it.

 

[FastDriver]

with a 10" run ~6.5" back spacing. With a 9", run 5.9-6". So what if you need to roll the fender or beat in the inner tub a bit. It'll work.

 

[Warhorse Racing]

How significant is this increase in the real world?

What I mean is: An 8" wide tire in front and a 10" in the rear seems like it would add [less] understeer than rebuilding a worn out traction lock. Do you consider this to be correct or will this kind of stagger have more effect than I think it would?

Now, skinnys... Never on the street IMO and dangerous for a [lot] of reasons.

If they are driving the car normally and responsibly on the street, most people probably won't notice the added understeer with a staggered setup. But, when they decide to push the car, they get surprised by the fact that they have more rear grip than front grip (the car understeers). And, in an emergency situation on the road, getting surprised by understeer can be a very bad thing. It's kind of like the "factory-installed" throttle-induced tendency to oversteer that these cars are born with. You have to make sure you're not driving the car into its negative tendency.

An autocross course is basically a series of evasive maneuvers. Speeds are usually under 65 mph. You cannot (and should not) drive on the street like you would on an autocross course. But autocross does give you a window into how your car would perform in real-world emergency situations. The most common staggered setups I encounter on 79-04 Mustangs are 245/275 or 275/315. When I get into a car with a staggered setup (that doesn't have mods/adjustments to compensate for it), I know it's going to understeer in certain areas on the course.

I would never tell anyone not to build their car the way they want it to look, but I always make sure people understand that there is a downside to staggered wheels and tires if they plan to use the car for performance driving.

 

[Noobz347]

Hey look what LMR just dropped:


View: https://www.youtube.com/watch?v=kPw-KqIpHcs