Mach1 8.8 Into My Fox

sen2two

I've been lubing and pulling it all morning
Jul 18, 2013
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My Fox is already 5 lug, but still has drum brakes in the rear. I want full disc brakes. So instead of piecing mine together, and having to do some tear down and build up. I want to just swap a 5 lug disc brake rear. I found a complete mach1 rear on CL.

From what I can find from searching, it's A direct swap. It's .750" longer each side (1.500" total), and I'll have to make my brake lines. And already has 3.55 gears.

So that's the easy part. I wasn't able to find information about brake caliper piston and rotor size. I do not want the rear brakes over powering the front causing unstability.

Anyone has this info? Or done this swap already and have some advice?
 
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My Fox is already 5 lug, but still has drum brakes in the rear. I want full disc brakes. So instead of piecing mine together, and having to do some tear down and build up. I want to just swap a 5 lug disc brake rear. I found a complete mach1 rear on CL.

From what I can find from searching, it's A direct swap. It's .750" longer each side (1.500" total), and I'll have to make my brake lines. And already has 3.55 gears.

So that's the easy part. I wasn't able to find information about brake caliper piston and rotor size. I do not want the rear brakes over powering the front causing unstability.

Anyone has this info? Or done this swap already and have some advice?

you can get an adjustable proportioning valve from LMR:
https://lmr.com/item/M2328C/Mustang-Ford-Racing-Adjustable-Brake-Proportioning-Valve

That works like a charm. You'll also need to upgrade your master cylinder and brake booster. I have 93 cobra pieces in mine (i think....been a while) but you can also use SN95 parts.
 
I didn't mention it because I didn't want to stray away from my question. But I will also be converting to manual brakes (no booster) using a 1" bore master cylinder. That should take care of that. Depending on how the brake pedal feels, I might have to modify it a bit for the correct pedal ratio.

I'm just concerned because I believe the mach1 got larger rotors. And potentially stronger calipers....? I don't want to have stronger rear brakes and have to compensate by adjusting the bias. I would much rather have correctly sized brakes in proportion to eachother.
 
My Fox is already 5 lug, but still has drum brakes in the rear. I want full disc brakes. So instead of piecing mine together, and having to do some tear down and build up. I want to just swap a 5 lug disc brake rear. I found a complete mach1 rear on CL.

From what I can find from searching, it's A direct swap. It's .750" longer each side (1.500" total), and I'll have to make my brake lines. And already has 3.55 gears.

So that's the easy part. I wasn't able to find information about brake caliper piston and rotor size. I do not want the rear brakes over powering the front causing unstability.

Anyone has this info? Or done this swap already and have some advice?
Unfortunately mines already came with all around disk brakes. If thats your Mustang in the picture, it looks really nice. Like that big hood. Completing the disk brakes is a plus. Good luck.
 
I didn't mention it because I didn't want to stray away from my question. But I will also be converting to manual brakes (no booster) using a 1" bore master cylinder. That should take care of that. Depending on how the brake pedal feels, I might have to modify it a bit for the correct pedal ratio.

I'm just concerned because I believe the mach1 got larger rotors. And potentially stronger calipers....? I don't want to have stronger rear brakes and have to compensate by adjusting the bias. I would much rather have correctly sized brakes in proportion to eachother.
In that case, you just need the proportioning valve. It installs on the fire wall just above the A/C dryer in place of the coupler. Very easy to install and adjust for proper gain.
 
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The mach 1 has the same brake setup as the cobra. With the change in track width you may have issues rubbing on your fenders. You can try and offset this by running s197 spec wheels. They have more backspacing that pulls the wheel in a little more.
 
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The mach 1 has the same brake setup as the cobra. With the change in track width you may have issues rubbing on your fenders. You can try and offset this by running s197 spec wheels. They have more backspacing that pulls the wheel in a little more.


I have 03/04 Cobra Wheels on the car right now. I should have enough room for the added 3/4" on each side. Worst case scenario, I'll have to step the tire size down a little and/or roll the fenders some.
 
The 94-98 Mustang rear axles were 3/4" longer per side. The later models 1999-2004 were 1.5 longer per side. I believe that the axle housing is longer as well.
 
it would be easier to swap the Mach 1 stuff into your current housing. There are a few other parts you need to find though.


Lets start with the cons of the mach 1 axle.
Lower control arm holes are larger starting in 1999. You will need some sort of adapter sleeve machined to work with pre-99 arms.
Brake lines. Mach 1 had the brake lines mounted on the body. Fox is on the axle, so you'll need to add the lines and use 94-95 rear mustang soft lines and brackets.
Axle width. The entire housing is 1.5" wider than a 86-98 housing. Then, the disk brakes add another .75" each side. So it's 3" wider than a Fox housing with drums. Makes picking wheels a little tough.


Now, swapping the parts over to your axle housing.
The brakes will completely bolt on.
You need to source 94-98 Mustang 5-lug axles (v8 or V6)
You can use your fox brake lines, with adapters to connect to 94-95 mustang rear soft lines.


Specs on the brakes. 38mm caliper piston (same caliper as GT/V6, but with different pad support bracket) and 11.65" vented rotors (vs 10.5 solid rotor on GT). Smallest wheel you can mount is a 16"..maybe. Only expensive 15" drag rims clear.

As for brake bias, just install an adjustable PV and you can reduce power to around 50%.

Of course, then you need a new MC and possibly booster. What's up front?