Fox Rear Big Brakes with OEM parts

KRUISR

5 Year Member
Apr 16, 2015
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So last summer I did a 5 lug conversion on my Fox and used Cadillac XTS Brembo calipers and Shelby 14" rotors up front. I used S197 rear rotors (11.81") at the time knowing I would get something bigger later.

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What am I going to install...

I found the Taurus Police Interceptor has 13.6" rear rotors (13.86" front). Since I have the 18" wheels already I figured why not. It turns out it is easier than I had expected.

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For reference, the rotor on the left is a 13.23" Mustang front rotor, the rotor on the right is a spare 12.99" front rotor I have for my '04 F150. In the middle is what I will be using.

Initial mock up to see what we are in for...

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This is the Police Caliper and as is, it is close, just a little clearancing on the axle bracket.

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Essentially I bolted a 1/2" washer and traced the outline. Then with an angle grinder and flap wheel ground/sanded back the material until I got to my scribe mark.

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The other bolt tab needed the same. I used the same template.

This got the caliper just nice down on the rotor.

More in post #2
 
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I came up with a bracket to connect the axle bracket to the caliper.

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Spacing side to side and caliper to rotor looks good.

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Front, rear and top side looking down at rotor and pads.

To making the second adapter bracket...

I made the brackets out of some 3/8" x 2" flat bar I had. The steel was marked for the 2.5" and 5" mark. Spacing between the two horizontal lines is 32mm. Then the hole centers were marked at 90mm c-t-c for the 1/2" diameter caliper holes and 97mm c-t-c for the axle bracket holes, drilled and tapped for M12x1.75 bolts.

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More in post #3
 
The first post shows the offset from the back of the caliper bracket and axle bracket. It worked out to be two (2) standard 1/2" washers.

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In second pic you can see the washers and the notch needed to clear the bottom of the caliper. Not much work, I just used the angle grinder and flap disc again to remove an 1/8-3/16" (I didn't measure and it is not critical, just needs to clear).

All bolted up, the front of the caliper bracket is close to rotor.

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The third pic shows 0.031" of feeler gauge that is tight, but does move.

So this is what I have completed. This will be going on my Mustang in the next month or so before I get it out of winter hiding.

Other things still needed...

Brake hose: The caliper uses the same thread pattern for the brake line and will re-use the line currently on my car.

Parking Brake Cables: This one was the challenge with the build. The caliper end of the cable is different than the Fox and SN cables (I currently have '95 cables).
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Pic of cable from Taurus. I am looking at a cable from either a Ford Flex or Ford Edge as they have the same caliper end and a barrel end that will work with my current Parking Brake Handle and are close enough in length when compared to the SN cable.

More to come when the project moves to install on the car.
 
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I like this.. .but will there be any issue with bias, having 14"/13“?


On a side note, what was involved fitting the 14s up front vs the standard cobra rotors?
The size of the rotor does not determine the bias, it will add thermal capacity and weight though. The 43.5mm piston on the caliper however will bring it back to almost stock ratio's and thus he should be able to run a 94/95 GT master cylinder assuming it still has the vacuum booster and the Caddy brembos.
 
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Rockauto lists the caliper piston at 43.5mm


That's the same piston size as the 93-97 Taurus 43mm caliper than is a direct swap for the SN95 rear calipers. Parking brake mechanism is the same as the Sn95.
I do not know how the pad area or rotor overhang compares however.
 
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That's the same piston size as the 93-97 Taurus 43mm caliper than is a direct swap for the SN95 rear calipers
Yup. The Lincoln LS rear caliper I have on the car now is 43mm piston as well. My concern with that older Taurus or the Lincoln caliper is the pad sweep you mentioned, as well potential issue with not getting the caliper low enough on the rotor. That is why I am going to use the caliper and rotor as a pairing from the same vehicle. This way I know the caliper and pad with work with the rotor. That is what I did when I used the Lincoln LS rotor and caliper to make my 4 lug rear disc set up 5 years ago.

you guys should figure out how to use C7 stingray bakes,
The problems include being Brembo type and needing a secondary parking brake caliper or drum set up (like the Corvette). The rotor size is 13.3" (Taurus PI is 13.6"). Wrong bolt pattern on the vette (Taurus is bolt on) and haven't looked into the offset if it would work or not.


GroverDill - you want Brembos in the rear, how is this ...

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Just for :poo: I thought I would try this set up. This is the 13.23" S197 front rotor pictured above with an ATS/CTS front caliper. No idea if the wheel will fit on (it should as the same combo will work on the front). Looking at the setup, I would want to make a new axle bracket from scratch to allow the caliper to sit low enough, or relocate the axle bracket to the back side of the axle flange - maybe still a custom axle bracket. Might not even need a shim. Still need something for a parking brake though.
 
The size of the rotor does not determine the bias, it will add thermal capacity and weight though. The 43.5mm piston on the caliper however will bring it back to almost stock ratio's and thus he should be able to run a 94/95 GT master cylinder assuming it still has the vacuum booster and the Caddy brembos.
I have a 94/95 vac booster with a 1-1/16 MC and a prop valve from a 2000 non ABS car. No aftermarket rear prop valve.

what was involved fitting the 14s up front vs the standard cobra rotors?
Rotors required nothing, just installed on OEM spindles - I have 96-04 style on my Mustang.

For Caddy XTS calipers I had to make some modified threaded inserts as defined elsewhere by Mustang5L5. Once made and installed a slight amount of clearancing with a flap wheel made install easy.

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For Caddy XTS calipers I had to make some modified threaded inserts as defined elsewhere by Mustang5L5. Once made and installed a slight amount of clearancing with a flap wheel made install easy.

Wrote it up here. It never made it further than my bench however. Too bad. They were massive brakes