Tire size With Current HRE Wheels

Pauliejr

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Need some help with my current setup

I am running HRE FF01s
20x9.5 +35mm
20x10.5 +45mm

Currently running
285/35/20
305/35/20

the car is lowered on BMR springs and it appears I have some running issues in the rear/possibly the front?

it would appear I’m rubbing on my drivers rear, I do have an adjustable pan hard bar and may be able to shift it slightly more towards center.

i have not had the car aligned yet and maybe some camber up front will tuck the tires better.

is there a better size tire I should be running with this offset for better fitment.

these are AS Tires so will be putting a performance set at least on the rear for the warm weather.

also appears right driver rear wheel gap is tighter than the passenger ?
 

Pauliejr

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Forgot to mention I have both lCA relocation brackets as well as BMR non adjustable lCA. The driver side I think definitely needs to shift slightly inward/ however I would my problem would just go to the passenger side.

wondering if my offset and tires is ok
 

Catmonkey

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Smaller tires might help, but that's not much you can do about too little offset. I think you're shy about 12-20 mm of what will tuck the tire in the wheel well. Adjusting the pan hard will help some, but whatever you gain on one side, you will lose on the other.
 

Pauliejr

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Anyone have any suggestions on wheels? Not sure why they recommend +35mm and +45mm for the vehicle. I’m assuming they are fine without a lowered vehicle.

Love these wheels and they aren’t exactly cheap.

I want o avoid getting new tire, still having issues. Then having to get new wheels and then tires AGAIN.

will have to upload pictures from my pc after work.

Does appear the front is rubbing as well.

any thoughts on direction?
 

Catmonkey

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What I've done to check fitment, and to see how the tire can contact the fender, is to remove the rear coil springs and jack up the axle see what and where it's rubbing. You should be able to determine how much more offset you need, or how much less tire you need, to clean. I'm running 11.5x20s with 61mm of offset on 325/30s and I'm not rubbing.
 

Pauliejr

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What’s odd is all wheels for this year call for +35 up front and +45 in the rear, which is what I am running.

I would think up front I am running a 285/35/20. This tire does bulge pasted the face of the rim, going with a skinnier tire that sits flush to the rim maybe would solve my problem up front. Maybe a 265/35/20 ?

as for the back. I am running a 305/35/20. Doesn’t pass the rim as much as the front, however maybe a 295/30 will be better for the rear. Thinner and skinnier.

I’m assuming the recommended offsets are taking into consideration a lowered vehicle. I’d prefer to keep these wheels and not have to get both new rims and tires.

I also want to make sure I still have traction out back as I plan on and I take pulley tune shortly.
 

Pauliejr

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A 305/30/20 is 27.2” tall, and 12” wide

a 295/30/20 is 27” tall, and 11.6” wide

current rear tire is 28.4” tall, and 12” wide


For the fronts

A 265/30/20 is 26.3” tall, and 10.4” wide

current tire is 27.9” tall, and 11.2” wide

looks like I would gain some decent space by switching tires ?
 

Catmonkey

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Factory offsets are 44mm or 45mm for the front and 45mm or 50mm for the rear for the GT500. The wider you go, the more offset you need.

The sidewalls width on a smaller/shorter tire won't change much, but a smaller thread area will have more clearance. A shorter tire will also provide more wheel travel before the body hits the bump stop.
 

Pauliejr

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Literally every site for 13-14 Gt500 rims posts a 35mm and 45mm for wheels and people don’t have an issue.

given I am lowered (nothing crazy. BMR performance springs on SVTPP Suspension)

I’m going to go on a limb and say I chose poor tire sizes, and this should get me back into business going with a thinner shorter tire all around. The rims themselves do look pretty flush minus the tires.
 

Catmonkey

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Literally every site for 13-14 Gt500 rims posts a 35mm and 45mm for wheels and people don’t have an issue.
Vendor's or forum users with real world experience? Most of your cheaper wheels have shallow offsets, and while smaller tires would probably fit, larger, wider tires change that dynamic as you're seeing. I'm sorry my experience doesn't agree with all these other sites, but then I don't have anything to sell either. As you can see my tires tuck under the fenders and are almost an inch wider than yours, but then so is the offset. The fronts are 285/35-20s on 10x20s with 44mm offset. It's not off-the-shelf wheel offsets.

Shelby 26 Sep 21 19.jpg
 

Pauliejr

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Vendor's or forum users with real world experience? Most of your cheaper wheels have shallow offsets, and while smaller tires would probably fit, larger, wider tires change that dynamic as you're seeing. I'm sorry my experience doesn't agree with all these other sites, but then I don't have anything to sell either. As you can see my tires tuck under the fenders and are almost an inch wider than yours, but then so is the offset. The fronts are 285/35-20s on 10x20s with 44mm offset. It's not off-the-shelf wheel offsets.

View attachment 1624113

mai I’m better off running the same tired and getting new wheels. Rather than keeping the wheels I gave and getting smaller tires.

I was looking at Shelby wheels that are 40mm up front and 50mm out back.

I should be able to run my 285/35/20 and 305/35/20 with that offset correct?
 

_Satch_

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Literally every site for 13-14 Gt500 rims posts a 35mm and 45mm for wheels and people don’t have an issue.

given I am lowered (nothing crazy. BMR performance springs on SVTPP Suspension)

I’m going to go on a limb and say I chose poor tire sizes, and this should get me back into business going with a thinner shorter tire all around. The rims themselves do look pretty flush minus the tires.

Wheel offset numbers are based on wheel width center plane to the hub mounting face. The factory numbers are based off a 9.5 inch wide wheel. So if you add 1 inch to the rear wheel width, but not change the offset number, you've effectively added 1/2 inch to the inside and 1/2 to the outside of a factory wheel. I can't see 1/2 inch on the inside being much, if any problem, but 1/2 outward towards the fender lip may get tight, especially if you are lowered.

I am currently running a 20 X 10 front wheel with a 38 offset and a 20 X 11 rear wheel with a 54 offset, and everything clears, but I did do the bump stop relocation brackets and I also cut out the body mounting brackets on the rear. The 54 offset is moving the outer wheel face about .395 towards the fender, while moving the inner wheel face 1.104 inward towards the shock. My car is also dropped 7/8's with the Ford L Springs.

This is a good explanation of wheel offset. https://www.tirerack.com/wheels/tec...!b!!g!!+wheel +offset +explained&gclsrc=aw.ds

Hope this helps,
-Satch
 

_Satch_

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A 305/30/20 is 27.2” tall, and 12” wide

a 295/30/20 is 27” tall, and 11.6” wide

current rear tire is 28.4” tall, and 12” wide


For the fronts

A 265/30/20 is 26.3” tall, and 10.4” wide

current tire is 27.9” tall, and 11.2” wide

looks like I would gain some decent space by switching tires ?

Factory Tires are 27.4 Overall Diameter for the front and 27.9 Overall Diameter for the rear. Personally I think a 26.3 O.D. would look like rubber bands on the front. I used to have a set of Nitto NT05's on the front of mine that were 26.65 O.D. and they looked like there was not enough sidewall. Personally I never liked that look. I'm currently running a 27.6 O.D. front and a 28.4 O.D. rear, both in a Continental Extreme Contact Sport, on 20 inch wheels.
-Satch
 

Pauliejr

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I bit the bullet and ordered myself a set of Shelby wheels. 20x9.5 +40mm 20x11 +50mm

from what I'm researching this should fit with no issues and the rims should tuck within the fenders.

I'm going to see if my current tires fit on the new wheels as they are brand new.

the fronts should fit without an issue as the rim width is not changing, however I am moving from a 35mm to a 40mm offset.

the rear I am now going from a 45mm to a 50mm offset, and yes I am going from a 10.5 inch rim to a 11 inch rim, keeping the same tire size should stretch it a bit more in combination with the new onset I think I should clear. if not I will be replacing tires as well, however I believe I needed to get rims with correct offset which +40mm +50mm should be correct.
 

Catmonkey

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I bit the bullet and ordered myself a set of Shelby wheels. 20x9.5 +40mm 20x11 +50mm

from what I'm researching this should fit with no issues and the rims should tuck within the fenders.

I'm going to see if my current tires fit on the new wheels as they are brand new.

the fronts should fit without an issue as the rim width is not changing, however I am moving from a 35mm to a 40mm offset.

the rear I am now going from a 45mm to a 50mm offset, and yes I am going from a 10.5 inch rim to a 11 inch rim, keeping the same tire size should stretch it a bit more in combination with the new onset I think I should clear. if not I will be replacing tires as well, however I believe I needed to get rims with correct offset which +40mm +50mm should be correct.
Front's should be okay. But the difference between 45mm and 50mm is under a 1/4".... and you're going with a wider wheel which will increase the cross section. This memory so it might not be dead on accurate, but it's close. I believe the cross section measurement on the stock SVT PP wheel/tire combination was 10.9". I've had a few different Michelins on 11" wide rims and the cross section always came out to 12.6". To center that in the wheel well, so that the outer profile is in the same position, you need a 64mm offset (50 + ((1.7*25.4)/2)=64). If you gave up a 3/8" of offset to get the tire flush with the fender, you'd take out 10mm, (1/4" would be 6mm) which puts you at 54mm (or 58mm for the 1/4"). It would still be tight, but you'd have clearance. Now the tread width is usually narrower than the cross section, but with a lower car and taller tires, it will still make contact. At least with too much offset, you can run a spacer if you want less offset. With tool little offset, you're pretty much stuck with what you got.
 

tomshep

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I think you are going the correct direction with the new rims. Which rims are they? The rims currently offered are designed around the S550 chassis but they advertise them for the S197 chassis. I've always wondered how they would work. I do like the fact they are 9.5 and 11. I am running a 275/35/20 on the front with a 9" rim which fits nicely. Your 285/35 should work on the 9.5 but that is a large tire, IMO, for the front. I am running a 315/35/20 on the rear, and I wish there was less height with them, on a 11" rim. They do match nicely with the front setup. What I am getting at is you can get the tires to fit if you can get the correct offsets as Catmonkey stated.
DSCN7773.JPG
DSCN7784.JPG
 

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