Tire Rub

[kccobra]

MK-IV build w/Coyote 5.0 engine. 245-45-17's on the front and 275-40-17 on back. Left front tire has prox 3/4" gap tire to top of fender. Going over bump i'm getting tire rub. Suspension has been aligned, loosened front body bolts and tried to lift body with little success...any ideas would be appreciated.

[Jeff Kleiner]

Your ride height is...???

Jeff

[kccobra]

Your ride height is...???

Jeff

4-1/2" from floor to bottom of frame.

[Jeff Kleiner]

OK then, next question... what spindles? '96 and later put the wheel about 1/2" farther outward than '94 or '95 SN95s, Fox or FFR spindles.

Jeff

[kccobra]

FFR spindles that came with the MK-IV complete kit.

[erniek70]

I have a mkIV chassis (2013 build), 3.75" ride height at front, 4.5" at rear, 275/40R17 tire on steer axle. I get tire rub on harsh bumps, and in tight low speed turns. Should I change to 245s? The rims are 9" wide? Should I just raise ride height? Help!

[BEAR-AvHistory]

I have a mkIV chassis (2013 build), 3.75" ride height at front, 4.5" at rear, 275/40R17 tire on steer axle. I get tire rub on harsh bumps, and in tight low speed turns. Should I change to 245s? The rims are 9" wide? Should I just raise ride height? Help!

I would try raising it to 4" in the front. Will check my exact height, may have settled, in the morning. Have a Mk-IV with Nitto NT01 Tires - 275/40R17 98Z on the front without any rubbing

[erniek70]

I have same size tire, Nitto 555

[CraigS]

If it only hits on one side shifting the body may be the fix. It is difficult to do though. The front body mounts need to be bent sideways.
189588
See the red lines above. The problem is that if you want to move them 1/2inch you probably need to bend them an inch and then they will spring back to that 1/2inch which is hard to do w/ the body on. If you try to move them, don't forget to remove the screws/bolts under the rocker panel where the body is attached to the frame. Those holes may need to be opened up into slots and a fender washer used when reinstalling screws. And then this may mess up your door to body alignment.

[Jeff Kleiner]

I have a mkIV chassis (2013 build), 3.75" ride height at front, 4.5" at rear, 275/40R17 tire on steer axle. I get tire rub on harsh bumps, and in tight low speed turns. Should I change to 245s? The rims are 9" wide? Should I just raise ride height? Help!

Was the excess mold flashing trimmed from the wheel wells when the bodywork was done? If not that's likely a big part of your problem. Beyond that another contributor can be caster and camber; what are yours set to? If you have very little negative camber the tire can contact at the top upon compression (bump); very low positive caster can allow the tire to touch at the front of the wheel well when turning.

Jeff

[Avalanche325]

I have a mkIV chassis (2013 build), 3.75" ride height at front, 4.5" at rear, 275/40R17 tire on steer axle. I get tire rub on harsh bumps, and in tight low speed turns. Should I change to 245s? The rims are 9" wide? Should I just raise ride height? Help!

That is a lot of rake. I started with 1/2" and took it all out. The car is better on track and autocross running flat. I am running a 3-link. 275 is a lot of tire up front. If I were you, I would try 4" all around. Keep in mind that changing the rear might need a pinion angle adjustment.

[Hoooper]

I have some very mild rub with 275s up front, 4" ride height, -2* camber. Basically just enough to scrub marbles off the edge of the tire and polish the tire shoulder. Fender edges all trimmed back, only happens on track. Assuming you have front wheels that match the FFR spec, I would think you either need more negative camber or the body alignment is way off to that side.

[erniek70]

Was the excess mold flashing trimmed from the wheel wells when the bodywork was done? If not that's likely a big part of your problem. Beyond that another contributor can be caster and camber; what are yours set to? If you have very little negative camber the tire can contact at the top upon compression (bump); very low positive caster can allow the tire to touch at the front of the wheel well when turning.

Jeff

I do not know what the caster is, I purchased someone else's build and I have not measured it.

[erniek70]

Was the excess mold flashing trimmed from the wheel wells when the bodywork was done? If not that's likely a big part of your problem. Beyond that another contributor can be caster and camber; what are yours set to? If you have very little negative camber the tire can contact at the top upon compression (bump); very low positive caster can allow the tire to touch at the front of the wheel well when turning.

Jeff

I'm only guessing the access fiberglass was trimmed during the initial build because there is not much there.

[erniek70]

If it only hits on one side shifting the body may be the fix. It is difficult to do though. The front body mounts need to be bent sideways.
189588
See the red lines above. The problem is that if you want to move them 1/2inch you probably need to bend them an inch and then they will spring back to that 1/2inch which is hard to do w/ the body on. If you try to move them, don't forget to remove the screws/bolts under the rocker panel where the body is attached to the frame. Those holes may need to be opened up into slots and a fender washer used when reinstalling screws. And then this may mess up your door to body alignment.

Hits on both sides

[BEAR-AvHistory]

Confirmed mine is 4" in front & back

[erniek70]

looks like camber should be -0.5, but you have at -2, correct, for a manual rack, MKIV?

[erniek70]

thanks....I may just raise mine up....

[Hoooper]

looks like camber should be -0.5, but you have at -2, correct, for a manual rack, MKIV?

It's set up for track use. -2 camber and +6 caster. Manual rack mkiv