Rear Wheel Fitment issue on a MK1 Solid Axle Halibrand 17 x 10.5 with 315s mounted

[zubie88gt]

I own a FF Mk1 roadster assembled in 1998 from a 1988 ford mustang donor with 4 lug 15 inch trims mounted with 245 / 275 rubber with a solid rear axle.

I was able to buy new Halibrand 17 inch FF rims (5 lug) on this forum last year and those rear rims are 17x10.5 with 6 7/8 backspaced where I have mounted 315 Toyo proxies R888 rubber.

I have been performing suspension / and a 5 lug conversion this winter and the front has worked out perfect. I have begun the 315 MOD on my MK1 to fit these monsters in the back and quickly realized I have a bigger issue. The outside of these tires will not clear the fender lip past 2.5 inches of suspension compression. My suspension travels up to a max of 3.5 inch's. With both my converted 5 lug axles installed the total axle width is 59.25 inches and the drum brakes are still on there. (5 lug drums from a ranger)

Looks like this with the rear suspension compressed:

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179506
179507

and it should look more like this-

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Is the Mk1 body not wide enough? I have read where MKl and MKll owners fitting 17x10.5 with 315s with 6 7/8 backspacing mounted in there on a 59.25 inch wide axle and clearing the Fenders edges. Seems that these wheel are sticking out 1.5 inches too much on each side. If I properly finish the 315 mod I will add almost 1.5 inches of clearance created on the inside where the wheel could move further back.

In everyone's experience, what are my options to fix?

1) Bump stops on the rear coil over suspension. I would rather not.
2) Narrow the rear to pull the rims in. (Use a narrowed rear at 56 inches wide could do it.) COSTLY
3) Flare the fenders to add more space. 😲 HELL NO!
4) Buy smaller tires. NO!

Is there a Halibrand 17 inch rim where the backspacing is larger with a width of 10.5 inches or some other fix?

Thoughts? I appreciate everyone's input on this forum.

[Gordon Levy]

It would be easier to widen the quarter panels

[Jeff Kleiner]

FYI, The #52 car (I happen to know it well) is a Mk3—Factory Five widened the rear fenders on the Mk3 cars 1.5 inches from what they were on Mk1 and 2.

Jeff

[zubie88gt]

Riddle me this Batman....

What if I bought 2 more 17x9s, send them to a rim shop to widen them to 11 inches, and make extra space in the truck area to accommodate them. (315MOD+ extra 1/2 inch) 11 inches should lessen the bulge of the 315s over the rims. I love the look of deep dish of the rear rims but would give it up to have 315s on the car instead. Tonight just for $hits and giggles, I mounted the the front 17x9s with 255s to the rear, jacked the rear up and they clear the fender lip allowing the suspension to travel over 4 inches before the tires hit the inside of the fender higher up. (Which is plenty of movement considering from stock ride height with me in the drivers seat along with my spring rate the most the rear goes up is 3.5 inches) Thoughts on that approach?

[Gordon Levy]

Proper ride height in the rear to the bottom of the frame is 4.5", any lower is unrealistic for the street. Actual suspension travel is about 1.5" max under compression unless you hit something really big. The 315 mod works best on an IRS car because camber is adjustable and you can move things around a bit. Live axle not so much unless you play with some aftermarket axle lengths. Off the shelf they range from 29" to 29.6. beyond that it gets expensive.

[Jeff Kleiner]

If you have room to go inward talk with Team III about some of their custom offsets.

http://www.etmags.com/ac_iii.html

Jeff

[rich grsc]

Riddle me this Batman....

What if I bought 2 more 17x9s, send them to a rim shop to widen them to 11 inches, and make extra space in the truck area to accommodate them. (315MOD+ extra 1/2 inch) 11 inches should lessen the bulge of the 315s over the rims. I love the look of deep dish of the rear rims but would give it up to have 315s on the car instead. Tonight just for $hits and giggles, I mounted the the front 17x9s with 255s to the rear, jacked the rear up and they clear the fender lip allowing the suspension to travel over 4 inches before the tires hit the inside of the fender higher up. (Which is plenty of movement considering from stock ride height with me in the drivers seat along with my spring rate the most the rear goes up is 3.5 inches) Thoughts on that approach?
I think there is zero chance you will ever see that much axle movement, this isn't and off-road vehicle. :)

[David Williamson]

On my Mkll I have 275/40 Nitto 555G2 tires on 17 - 10.5 wheels, they fit but are slightly pulled on the rim, don't look odd. I have a Fox width 3 link setup so I can center the axle and it works with a ride height just under 4 inches.
Another option
David W

[mburger]

I’m feeling really stupid but I have to ask, what is the 315 mod?
I’m just wondering if there’s something else I can spend money on.

[Gordon Levy]

I think there is a how to in the FAQ's. Basically moves the inside trunk side panels inboard similar to the current Mark IV position.

[weendoggy]

I’m feeling really stupid but I have to ask, what is the 315 mod?
I’m just wondering if there’s something else I can spend money on.

It envoles a lot of frame cutting and movement of some aluminum in the forward trunk and door/firewall area to accomodate the larger width tire. It can be done with body on, but a lot of work. My MKI (IRS) runs 285's in the rear without problems and I have buddies with the same on solid axle. Not much to trim for that size. There's a thread somewhere in the forums that go through it, but if you're willing, you can figure it out.

[Gordon Levy]

Also Nitto makes a 285/40/17 that fits pretty well on the 10.5 wheel and is much bigger than the 275.

[GoDadGo]

Also Nitto makes a 285/40/17 that fits pretty well on the 10.5 wheel and is much bigger than the 275.

I'm running 285/40/17 Nitto's on my MK-4.
On the front I'm running 245/45/17's.
Hope this helps & sorry if it doesn't.

https://youtu.be/9WEe6-wdNtA

Good Luck!

[zubie88gt]

Thank you for all comments so far. I will check ride height from rear to the bottom of the frame to be 4.5" As for the suspension travel dimension of 3.5 inches, that dimension is from full axle drop when car is off the ground to the max compressed travel I have measured so far when driving. Dirt on the rear coil over adjustable QA1 shock shaft as shown me that. I am not off-roading my cobra. LOL!

Just to add some more detail, for my 4 link suspension I also have LCAs and UCAs that are fully adjustable and are installed with spherical bushings at all connection points so I can locate the rear position, set proper Pinion angle, and reduce suspension bind under hard acceleration. Quad shocks are GONE....

I like the "Team III" comment from Craig and will call them today so I can price out that solution. I will also let them know that they need to add tags to their website so when someone googles "17 inch halibrand wheels" there site should come to the top of the result list or at least show up in the first page of a search. 315s will be on this car! WOO WOO!!!

[mburger]

I think there is a how to in the FAQ's. Basically moves the inside trunk side panels inboard similar to the current Mark IV position.

Thank you!

Henry, I think it’s time to pull the body again!
Then I can add the foot protection, backbone and the “315” mod. ;)