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View Full Version : Will 17x9 RPF1's rub the front control arm on a fox?



90GT
01-23-2019, 07:18 PM
Im hesitating on ordering some RPF1's for the front of my 1990 GT. Im looking at the 17x9", +22mm offset, 5.875" backspacing. The front is lowered 1.5" and Im hoping the wheel wont rub the front control arm at full lock like some wheels do. The reason I'm choosing that size wheel is because i have the 5 lug (Ford M-2300-k) brake upgrade and this is the closest size to the Ford R58 wheel that Enkei offer. I figured staying as close to the Ford R58 and M179 wheel specs was probably a good idea.

What's everyones thoughts on this? Will it rub? Does it even matter for street driving? If it makes a difference, i plan on running a 255/40 tire.

fast Ed
01-23-2019, 09:44 PM
Do you still have factory lower control arms? If so, you will likely have to limit the steering rack travel a bit more than stock to keep things from rubbing at full lock.


Cheers
Ed

Mustang4
01-23-2019, 11:22 PM
Im hesitating on ordering some RPF1's for the front of my 1990 GT. Im looking at the 17x9", +22mm offset, 5.875" backspacing. The front is lowered 1.5" and Im hoping the wheel wont rub the front control arm at full lock like some wheels do. The reason I'm choosing that size wheel is because i have the 5 lug (Ford M-2300-k) brake upgrade and this is the closest size to the Ford R58 wheel that Enkei offer. I figured staying as close to the Ford R58 and M179 wheel specs was probably a good idea.

What's everyones thoughts on this? Will it rub? Does it even matter for street driving? If it makes a difference, i plan on running a 255/40 tire.

When I ran 17x9" Cobra rims on my 1991 with +24mm offset and 6" backspacing the front wheels hit the back of the rim on the front control arms on full lock, such as parking, not to mention brushing fender lips going up driveways on a turn. I had to go to rack limiters to stop the wheels from hitting the front control arms. You really need, more offset like +30 to + 35mm for best fit.

Ponyryd
01-23-2019, 11:45 PM
Yes it’s very, very likely they will rub, but you can use steering rack limiters, or swap out control arms to remedy this. Or you can do like I did with my ‘91, and cut the welds off the control arm rear support pads, and give the arms a little massaging with a bfh to get the room you need-of course that’s not the proper way to do things, but it worked for me ;)

RedSN
01-24-2019, 10:38 AM
...you can use steering rack limiters, or swap out control arms to remedy this. Or you can do like I did with my ‘91, and cut the welds off the control arm rear support pads, and give the arms a little massaging with a bfh to get the room you need...
I like option B the best. ....because it snowballs into getting coil-overs, CC plates, tubular k-member, etc. etc. etc.

fast Ed
01-24-2019, 11:06 AM
That's the trouble ... if you use the OEM 99-04 Mustang arms that are shaped with more clearance, they also push everything out further unless you have a crossmember to match. Or go aftermarket control arms, and then start with the "might as well while I'm there!" ...


Cheapest option will be the additional rack travel limiters, Ford hardware # N804842-S. They come in a package of 4 for about $20, add one or two extra per side as needed. Downside of course is that your turning circle gets increased.


cheers
Ed

90GT
01-24-2019, 02:24 PM
Thanks for all the info guys! Enkei offer a 17x9 +35mm offset and 6.375" backspacing. Would that wheel fit better up front? I was looking into the front control arm swap, and found these from BMR Racing, but have never heard of anyone using them or if they actually improve wheel clearance at all..

https://www.bmrsuspension.com/?page=products&productid=1802&superpro=0

as for the BFH method.. I have cut off that welded on square piece, maybe i can find a BFH laying around someplace..?/ lol

hammerhead
01-24-2019, 02:35 PM
My 3 pound BFH gets used the most of all my tools....lol

fast Ed
01-24-2019, 02:41 PM
Tucking the wheel in further with higher offset is not going to work, you'll be up against the strut and probably other stuff ... and less offset you'll be pushing to the outside and rubbing the fenders with the tires. Factory geometry Fox Mustang suspension can only take a max of about 6" of backspacing on the front. If you had suspension parts in place that increased the track width you could go with higher offset wheels, but in your case that's not going to help.

Can't comment on those BMR arms as I have no experience with them, but looking at the web page and clicking on "features", there's no mention that I saw of increased wheel/tire clearance.

hammerhead
01-24-2019, 03:10 PM
with the 5.875 back spacing in the original post could be the correct wheel if the 6" rubs - you may be able to get away with rolling the fenders - maybe difficult to figure out wheel to fender clearance without the wheel - wider track is better handling - maybe you could borrow a wheel and give it a try..? I had a wider tire on the front of my fox - didn't rub on the control arm but the left front rubber side wall would touch the plastic inner fender slightly on tight turns....

jibbijib
01-26-2019, 08:33 PM
I like option B the best. ....because it snowballs into getting coil-overs, CC plates, tubular k-member, etc. etc. etc.

And the best part is the parts sit on your shelf for 5 years collecting dust until the night before track day!