Tire Rubbing

[Ewheels]

I have what I would consider a fairly significant amount of tire rub on my 2018 Mustang. The fronts (and to a lesser degree, the rears) rub on the outer edge of the tire against the outer-most portion of the fender.

19x11 +50 wheels, 25mm spacer, 305/35/19 BFG Rival S 1.5 tires, -3° of camber up front & -2° rear, 250# springs up front with Ford Track shocks.

I'm a bit surprised as this is the go-to wheel/tire setup for S550's but perhaps I'm missing something. Anyone have any ideas?

You can see below under full compression that the tire and fender become very close friends.

 

[Stangra]

Ride height?
Bumpstops modified?

 

[Ewheels]

Ride height?
Bumpstops modified?

Ride height: not certain. I think it's 3/4" drop from stock. Non-adjustable.
Bumpstops not modified. Actually, also not certain. They were hand-me-downs from @flyhalf

 

[JDee]

What springs are you using? The tire does look like it's really up in the wheel well.
I had Ford racing track springs on my '16 that lowered the car maybe an inch or so and there was very occasional light contact but nothing major.

 

[Ewheels]

What springs are you using? The tire does look like it's really up in the wheel well.
I had Ford racing track springs on my '16 that lowered the car maybe an inch or so and there was very occasional light contact but nothing major.

BMR Handling springs. 250 lb in the front.

Coilovers are on my wishlist of parts but I'm curious if I have some other fitment issue going on.

 

[JDee]

If you can get a little more camber it will pull the top of the tire inwards and it might help with clearance. I ran -4 with my '16 and it worked very well. Needed to use camber bolts and maxxed out Vorshlag plates to get that but the wear was pretty even across the tire.
People blather on about wearing the inner edge of the tire out but that never happened, the wear was still mostly on the outside of the tire.

 

[byronj]

IMO - Your front springs are way too soft. I have no issued and run the same width with less camber.

 

[Ewheels]

IMO - Your front springs are way too soft. I have no issued and run the same width with less camber.

I know Was curious if there was anything I could do in the mean time.
It's crazy how softly sprung these cars come factory.

 

[5.2 liters of democracy]

I don't know if it will help, but I have a set of Ford Performance springs laying around you can have. I'd need to check the spring rates to see if it is even an upgrade though.

 

[Ewheels]

I don't know if it will help, but I have a set of Ford Performance springs laying around you can have. I'd need to check the spring rates to see if it is even an upgrade though.

I think those are about the same rates as I have now. Either way, I'm pretty much capped out on these shocks. Any higher rate and it'll be too much spring for the dampers......I see coilovers happening quite soon.

Thanks for the offer though, amigo!

 

[JAJ]

I know Was curious if there was anything I could do in the mean time.
It's crazy how softly sprung these cars come factory.

This makes it obvious why FP put wider front fenders on the GT350/GT500's.

If you open up (cut) the top of the strut towers, you can get more clearance by tipping the strut top further inwards. More camber, yes, and more room.

However, if your camber plates are already maxed and you don't want to cut the strut towers, the only thing left is to is minimize the distance between the inner sidewall of the tire and the strut. I measure that gap by sliding an Allen key between the tire and the strut.

The closest that measurement should be is 5mm or 0.200 inches. That allows the tire tread to move under side-loads without the sidewall rubbing the strut.

Now there are two ways to get that spacing - measure the spacing now and order a new spacer that moves the wheel inboard just enough to leave a 5mm gap. The second way is to get some camber bolts and tilt the top of the tire inward until it's 5mm away from the strut. Either approach will give you as much clearance as is available on the outside of the tire without cutting the strut towers.

 

[byronj]

Allstar Performance ALL64404 Allstar Performance Bump Stop Components | Summit Racing

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You can go a a lot stiffer on the stock mag ride. I have some GC coil overs like AJ Hartmans near new if you'd be interested. They shaved 3 second off my time at Sonoma and the car never drove better. Even the wife which hates the ride said it rode nice.

 

[Ewheels]

This makes it obvious why FP put wider front fenders on the GT350/GT500's.

If you open up (cut) the top of the strut towers, you can get more clearance by tipping the strut top further inwards. More camber, yes, and more room.

However, if your camber plates are already maxed and you don't want to cut the strut towers, the only thing left is to is minimize the distance between the inner sidewall of the tire and the strut. I measure that gap by sliding an Allen key between the tire and the strut.

The closest that measurement should be is 5mm or 0.200 inches. That allows the tire tread to move under side-loads without the sidewall rubbing the strut.

Now there are two ways to get that spacing - measure the spacing now and order a new spacer that moves the wheel inboard just enough to leave a 5mm gap. The second way is to get some camber bolts and tilt the top of the tire inward until it's 5mm away from the strut. Either approach will give you as much clearance as is available on the outside of the tire without cutting the strut towers.

Strut towers are already cut. I could add more camber, may try that route though my tire wear seems pretty even....aside from the fender rubbing the very outer edge.
My pointer finger just barely fits between the tire and the strut. Maybe .375" gap
Perhaps slimmer spacers could be an option as well.

Allstar Performance ALL64404 Allstar Performance Bump Stop Components | Summit Racing

Free Shipping - Allstar Performance Bump Stop Components with qualifying orders of $109. Shop Shock Bump Stop Components at Summit Racing.

www.summitracing.com

You can go a a lot stiffer on the stock mag ride. I have some GC coil overs like AJ Hartmans near new if you'd be interested. They shaved 3 second off my time at Sonoma and the car never drove better. Even the wife which hates the ride said it rode nice.

I don't have mag ride unfortunately.
That is a brand I was looking at. Message me how much you want for them?

 

[Stangra]

You've got room for smaller spacers, an 1/8" is a mile if it works!
Slightly less weight too.

 

[o-man]

That's odd. I run 325's on my Bullitt on 19x11.5. 35mm spacer front, 5mm rear. No rub on rear, some rub on front with BMR handling springs and Magneride.

 

[Stan Whitney]

You've got room for smaller spacers, an 1/8" is a mile if it works!
Slightly less weight too.

This, your strut to tire clearance can be reduced to much smaller than 3/8". 1/8" can work, especially with stiffer sidewall performance tires.

 

[Stangra]

That's odd. I run 325's on my Bullitt on 19x11.5. 35mm spacer front, 5mm rear. No rub on rear, some rub on front with BMR handling springs and Magneride.

Wheel offset makes a difference too.

 

[Ewheels]

This, your strut to tire clearance can be reduced to much smaller than 3/8". 1/8" can work, especially with stiffer sidewall performance tires.

Time to look into thinner spacers then. Thank you sir.

 

[o-man]

I just realized you are running 35 series tires. Most folks usually run 30 series. Could that little bit of height difference be the cause of the rub?

 

[Ewheels]

I just realized you are running 35 series tires. Most folks usually run 30 series. Could that little bit of height difference be the cause of the rub?

Whoops, that should've been a 30 in my original post. Good catch.
I was going off memory.....which proved to fail me