Fox 5-lug Swap And Wheel Dimensions

FastDriver

My dad had a bra
SN Certified Technician
Sep 5, 2001
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I have the Baer Brakes Track kit installed on my '91 Hatchback and I want to confirm the wheel sizes that I need to order. I'll work out the rear wheel with Team-Z, but on the fronts, I really can't remember a damned thing. I am running Cobra Rs all the way around, which I thought would make it easy to look up, but even given the fact that they're OEM Cobra Rs, not aftermarket, there are still a couple types that have different offset and back spacing. I called Baer, but they couldn't say. I'm guessing I should just go with a 17x8 with a std. 4" backspacing up front.

I know I'm currently running 245/45/17s up front, but I honestly thought it was a 17x8" wheel. I also thought they were OEM Cobra Rs, and it looks like all the OEM wheels are 17x9" with a 5.9x" or 6.4x" back spacing. Maybe that's why I remember them rubbing a bit on the inside in sharp turns.

If anyone has a 5 lug setup without any rubbing issues, please throw me a bone.

Thanks,

Chris
 
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Im running 95 spindles, cobra big brakes, and 17x8 w/ 31mm BS. I really wanted the 17x8 SC fronts and 17x9 rear, found the last 17x8 at Wheel replicas in the SC wheel. tires are bfg sport comp II 245/45/17 and 275/40/17. She has coil over fronts at about 25" and 26' rear (rear is eibach pro, mm hd lca....

EDIT: it is mm k and reverse offset a arms

No rubbing at all, I do have the well liners in too!

WR - they really know these setups well, maybe they can give you specifics on other rims that'll fit

Please recognize tops not done yet in this pic,

5-21 mustang.JPG
 
91 here with 17X9 255 up front VERY minimal if any rubbing on bumps.... lock to lock is a different issue! I have limiters in the rack and that dramatically reduces turn in parking lot radius! I had to put them in because of wheels rubbing on the control arms during full lock.
 
IIRC, thse front brakes on that kit are the same as the Cobra 13" kit. I would assume they are using 96+ spindles as well? But not sure on that.

I was hoping you'd chime in. You're the most knowledgeable guy regarding 5-lug and brake parts on these cars. Yes, this is definitely the Cobra 13" kit, and IIRC also the older vettes. I don't know which spindles, though I believe whatever you say. Is there a difference between the 94-95 spindles and the 96+?

Im running 95 spindles, cobra big brakes, and 17x8 w/ 31mm BS. I really wanted the 17x8 SC fronts and 17x9 rear, found the last 17x8 at Wheel replicas in the SC wheel. tires are bfg sport comp II 245/45/17 and 275/40/17. She has coil over fronts at about 25" and 26' rear (rear is eibach pro, mm hd lca....

EDIT: it is mm k and reverse offset a arms

No rubbing at all, I do have the well liners in too!

WR - they really know these setups well, maybe they can give you specifics on other rims that'll fit

Please recognize tops not done yet in this pic,

5-21 mustang.JPG

Thanks for the info. 31mm must be the offset. BS is usually measured in inches. Thanks for the recommendation about contacting WR. I will follow up.

91 here with 17X9 255 up front VERY minimal if any rubbing on bumps.... lock to lock is a different issue! I have limiters in the rack and that dramatically reduces turn in parking lot radius! I had to put them in because of wheels rubbing on the control arms during full lock.

I don't recall having any issues with the Cobra Rs, even with the stock a-arms. Now that I'm running coil-overs and tubular a-arms, that will help with clearance too, but it doesn't do anything about clearance with my wheel liners. Do you have any idea what the backspacing is on your wheels? I'm guessing 6.42" or greater.

I have 17x8 stock 99gt wheels with. 245/45 and am lowered on c springs w/o isolators. No rub no issues. 94 spindles.

Thanks! I will search, but do you know off-hand what the Backspacing and offset are on the 99GT fronts?
 
After talking to weld, Phillip there was very on point and I think I've figured things out. It looks like the right front wheel will have a 5.8" back spacing whether it's a 17x8 or 17x9. They also take the Cobra brakes into account in the construction of the wheel and use a "medium pad" which moves the spokes away from rotor, giving it the needed clearance.

I found this on the other forum:
In fact, there are 3 versions of the '95 Cobra R wheels that are genuine Ford products: the M179 with a 6.42" backspacing for fox cars running the m2300k brake kit with sn95 axles, the R58 with a 5.98" backspacing (the "real" version), and the R54 (4-lug). All of these are/were available in chrome, as far as I can recall.

I'm probably running the 5.95" BS wheel (R58), as I remember the last owner telling me they were "real." I've never had significant rubbing issues. It just rubs the inner fender liner a bit when I'm lock-to-lock. I guess the m2300 brake kit sets the spindles farther out. I think the Baer must not.

It may be correct that he wants the R58s, but you can't differentiate them by the spoke design. The M179's spokes are exactly the same as the R58's. The difference between the two wheels is the thickness of the mounting pad, or whatever you want to call it, where it bolts to the rotor/hub.
That seems awfully similar to what Phillip told me about the medium pad.

ding ding we have a winner,the 179's were for fox's with a rear disc conv

Now I'm confident I had the R58s! My rear tires used to get gouged by the rear fender lips. If I'd had the M179, that wouldn't have happened. Score! I think I'll probably be fine if I go with Phillip's advice and keep the 5.8" back spacing up front.

In the rear, I'm planning to go with a 17x12" wheel and a 6.5" backspacing. A 325/45/17 M&H Drag Radial will probably fit, though they're ideal for an 11" wheel.
 
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I was hoping you'd chime in. You're the most knowledgeable guy regarding 5-lug and brake parts on these cars. Yes, this is definitely the Cobra 13" kit, and IIRC also the older vettes. I don't know which spindles, though I believe whatever you say. Is there a difference between the 94-95 spindles and the 96+?

96+ stick out about 3/8" more than the 94-95 spindles.


Easy way to tell what you have. Take a peek under the car and look at where the tie rods connect.

CastIronFinish_1.jpg


Rear spindle with the curved tie rod arm is 94-95. Front with the straight arm is 96+

After you know which, you are basically just comparing to guys with Sn95 cobra setups with that set of spindles. Since the 96+ units stick out a tiny bit further, the arc traveled during turning tends to be a little bigger so you may get some rubbing issues there. 17x9's tend to be an issue.



Rear brakes are C4 brakes IIRC with aluminum calipers. Nice stuff.
 
First, YAY FOR 3000 POSTS!

Well, I don't have the car here, but I did find this from my old build pics:

kmem driver brakes.jpg


It looks like you called it! Thank you very much!

edit: Actually, one follow-up question: Since it's the arc that causes them to rub, would adding wheel spacers just make the problem worse? I guess, like you said, I'll just have to see what others have done to resolve the issue. That said, it won't be at the top of my list. It was never so serious that I was worried about immediate damage to the tire. I think at worst case, it would eventually wear the wheel well liner down.
 
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: Since it's the arc that causes them to rub, would adding wheel spacers just make the problem worse? I guess, like you said, I'll just have to see what others have done to resolve the issue. That said, it won't be at the top of my list. It was never so serious that I was worried about immediate damage to the tire. I think at worst case, it would eventually wear the wheel well liner down.

It would, because you are pushing the wheel out further, so the arc it has to travel when you turn side to side is larger. If oyu use a wheel with a deep BS, the turning arc is smaller, but now the issue is contacting the A arms at full lock. however, with your setup, that might not be an issue.
 
Yeah, that'd be worth a try. Maybe I can find a wheel to borrow, first. Thanks for pointing out the backspace effect. I better reconsider dropping from 5.95" down to 5.8 as it would be equivalent to adding a spacer. It's counter-intuitive. Perhaps I will end up with an 8" after all, or maybe I'll get lucky and find someone with a 17x9 with a 6.2-6.5" BS to try out. For now, I'll probably just order the rear wheel.
 
Update: The guys at Team-Z tell me that the caliper comes passed the wheel mount surface by 3/8" on front and rear. So, Weld says they can use a "low pad" without clearance issues. This was necessary on the rear because the 17x12" wheel with a 6.5" backspacing only comes with a low pad. Now, all that's left is to order the right wheels.

I'm currently favoring a 17x8 or 8.5 up front to help with clearance there.