Front and rear track width

[RonKahn]

Hello all. I am in the process of building a CRII kit from the 1990's that was never assembled. I have the rebuilt 8.8 already installed with a 60 3/4" wheel mount face to face. BUT the front Mustang II double a-arm setup is only 56" wide wheel mount face to face. Is this normal? That is almost a 2.5" difference from the front to rear tracking. I know I can get wheel spacers and/or offset wheels, but is this normal for everyone? Yes, the a-rms are the normal length and not the short ones.

[RonKahn]

[Morris]

Ron

Keep 2 items in mind.....
A. The ideal Track to Wheelbase ratio is 70%.....
B. The front track always needs to be wider then the rear track.....

When designing chassis you almost always start locating the wheels first....and design the suspension and chassis to to the desired track and wheelbase needed.

[sunman]

The 86-93 Fox 8.8 rear end is 59 1/4 wide.
Your axels are too long, looks like the later 8.8 width
It’s 1 1/8” back of axel to the housing yours is more than that
I did go out and tape it to be sure
The wheel backspace effects track. Measure center of wheels for track width

[RonKahn]

I replaced the factory axles with Moser axles of the identical length, so they are factory length. I measured from the outside face of the hub that the wheel attaches to. Am I supposed to measure from the inside of the wheel flange? That measurement is about 59 1/2” from what I can tell. This is a CR2 chassis. It called for an early to mid 90's 8.8 from a GT, which it is. The front end I didn't use the stock Mustang 2 suspension, but am going with the Helix setup.

[RonKahn]

I take that back. I just checked the CRII parts book, and it did call for a 86-90 8.8 rear end, and not the 93-94 I have. That little bit should not be that much of a problem. Might just need to order wheels with the correct offset of course. Any other advice?

[RonKahn]

Originally Posted by Morris

Ron

Keep 2 items in mind.....
A. The ideal Track to Wheelbase ratio is 70%.....
B. The front track always needs to be wider then the rear track.....

When designing chassis you almost always start locating the wheels first....and design the suspension and chassis to to the desired track and wheelbase needed.

Thanks for the information, but I am slightly confused? The rear fiberglass to fit tires is over 5" wider that the front. Now, if the rear axle is wider, then then rear wheel won't have as deep of a dish to get the wheels to fit under the fender. I just don't see how any Cobra has its front track wider than the rear, unless I am missing something, and trust me, I am as dumb as people say I am....lol

[sunman]

The 1994 and up SN95 axels are 1 1/2” wider total. Up to 98 used same housing. Your axels stick out more. Check out the difference. Change them out *******AXELS ONLY*******
Put your wheels on to measure track width, it’s the wheel center
Fronts on this are 9” wide rim 3 3/4” backspace 245/50/16
Back 10” with 4 1/2” backspace 255/50/16
CR II supplied wheel size and backspace
You can go wider in back to the inside

[RonKahn]

Originally Posted by sunman

The SN95 axels are 1 1/2” wider total. Up to 98 used same housing. Your axels stick out more.
Put your wheels on to measure track width, it’s the wheel center

I dont have wheels yet, still have to purchase them. Right now, I just have some old Mustang factory wheels on them for now so to mock up everything. I was going to purchase rims and tires later, assuming I can get specific wheel offset/backspacing for each axle for my needs. I cant go wider in the front as it is factory width and a MustangII front end. You may be right, I have a wider rear end, which may cause me to not have as deep of a dish wheel. That will be unfortunate, but it is what it is right now. Not going to find another rear end and start over. Nor am I going to narrow this rear end.

[sunman]

You got no probs it’s axels only to change. Check edits to post above.
Front tires are a close fit probably as big as you want to get physical size wise
The back are 26” tall and easily could go 27” with 1” to 2” wider to the inside
The manual is 1990, good times...

Party On

[RonKahn]

Originally Posted by sunman

You got no probs it’s axels only to change. Check edits to post above.
Front tires are a close fit probably as big as you want to get physical size wise
The back are 26” tall and easily could go 27” with 1” to 2” wider to the inside

Party On

GREAT information sir. I will keep this when I get to that point. Yes, I could just change the axles, but that would be another $300+ for that. Anyway, we will see as I progress on this project. I ordered the QA1's over the weekend, so I should have them installed by the end of the week I hope. Everything should fit well I hope.

[sunman]

See if Moser will exchange the axels, super pros in my experience
Maybe send you some decals for the walls, good look for background in build photos

[t walgamuth]

Having the front track wider will make the car go straight better. The front track is dictated by the narrow fender contours. The rear at least on mine will take a huge tire with no danger of rubbing with the correct wheel backspacing.

[Chicagowil]

I believe what you have for an 8.8 rear axle is the later setup with disc brakes and the sensor wheel (missing) for the ABS. The shorter axles may cause a problem with the mounts for the rear caliper. Do a trial fit of the rotors and calipers to see how everything aligns.

I will check out my front track tomorrow. What is the outside width of your front fenders (side to side) on your CRII. I have a very early CRI. I assume they are the same.

Thom

[Chicagowil]

Here is the hub with the ABS ring



Thom

[sunman]

The hub shown is for the front.
You can’t/ won’t use the reluctor ring that is pressed on axel shaft for 94 and up. ABS? On a Cobra?
The hub diameter/ rotor hole ID is bigger for the SN95 rotor and requires a ring spacer to use early axels with SN95 rotors. SN95 brackets do not work you need custom brackets
I’m using SN95 brakes with a rotor hole spacer and the North Race Cars one piece anti-moan brackets. It’s a complete kit with everything but the brake lever

[RonKahn]

This axle came out of a 93 GT. It had the abs rings but I am not using them, hence the missing rings on mine. The axles I bought are exact fit length to what was originally the 28 spline axles, but these are 31 splines. I don't think I can change the axles and not have problems with the caliper/rotor alignment. I will check my front width but visually the front fenders are narrower than the rear. There would be no way to have the front track wider than the rear.

[RonKahn]

68" front width, 73" rear width body shell. My brake drums and everything I have new all fits on this rear end and axles. So far so good.

[Roylerumble]

might be irrelevant, but if you do need to swap out the axles to a fox body length axle, you can still use the sn95 brakes with a very simple mod. Uses a passenger axle from an Ford Aerostar, a drivers axle from a Ranger or Bronco II, and the calipers and mounting hardware from any SN95 mustang. I haven't done it, but I'm planning on doing it and have all the parts. Tony from Junkyard Doggs does a really good job of explaining how to do it. You can get the parts from a junkyard, or buy them new.
here's the link:
https://www.youtube.com/watch?v=9i8rC9fffnA&t=66s

[RonKahn]

Ok, I am confused. If my rear end is from a Fox Body mustang, and I purchased exact fit replacement axles to just replace the 28 spline with 31 spline, why would I need to do this Mod? All in the attempt to get maybe 1/2" narrower rear end? I already have the whole thing painted/powdercoated and wondering what the real results would be?