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Thread: 2015+ IRS 13" rear brake option

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    2015+ IRS 13" rear brake option

    Anyone know the reason why FFR decided to make their own bracket and rotate rear brake caliper (assuming you have a mk4 with IRS and 13" mustang brake option) to 12 o'clock position vs mounting it as from Ford at the 3 o'clock position as seen from driver side?



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    Last edited by Silv3rsurf3r; 04-05-2018 at 07:36 PM. Reason: test to post pic
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    This is a guess, look at the ebrake cable routing?
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    I don't know why they did that, perhaps they are selling an earlier model caliper with their brake kit. What I do know is that you can use 2015 mustang calipers mounted exactly the way they were on a stock 2015 mustang. I have the 13 inch GT brake rotors and calipers on my MK4 with 17 inch FFR wheels. The caliper clearance is very close and some slight grinding on the caliper casting may be needed, but they work just fine.
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    Senior Member Paul2STL's Avatar
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    I am pretty sure for clearance and so you wouldn't have to modify the calipers like i did. I am running the stock 15 Mustang brakes with 17 FFR rims and had to grind down the two casting nubs on top. I think there bracket pulls the caliper towards the center just a bit like a 1/4 inch or so. Here is the clearance on mine before I grinded those nubs off.



    And after grinding off the nubs on top of the caliper they cleared the rim and weights. Probably could have had the weights moved and rebalanced but the caliper rubbed the rim on the upper corner of the caliper. I used FFR park brake cables and so had to ask FFR if they would send me the adapter they make to connect to the 15 Mustang caliper if you buy their kit.

    MKIV #9122 Ordered kit 5/24/17 received kit 8/11/17 MK4 Base kit +,First Start 4/7/18, First Go-Cart 4/22/18, In gelcoat, licensed and driving 8/11/18. Coyote gen2, T-56, 2015 IRS 3.31, 17" Halibrand replicas w/Nitto NT555 G2, Withby Motorcars power brake kit W/Wilwood pedals, 04 Cobra front brakes, 15 Mustang rear brakes with mods, power steering. Paint Jeff Miller Da Bat, Lexus Spectra Blue Mica W/Toyota Silver Sky Metallic strips. Build thread: http://thefactoryfiveforum.com/showt...Paul2STL-Build

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    Well according to Dan at FFR the ebrake cable routing is the only reason why. I think I may dabble with the routing and see if I cant get it back to Ford spec, maybe just a little longer cables will do. I just don't like the severe bend the cable makes as it leaves the caliper to wrap around the shock; I can definitely feel more tension in the line routed that way than when its mounted the Ford way...just my .02 anyways
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    Senior Member edwardb's Avatar
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    I don't have experience with the Ford brakes, so take this comment for what it's worth. I'd be real careful about changing the mounting without fully understanding the implications. Factory Five obviously went to some work and expense to mount that caliper like that. Not questioning Dan personally, but I'll bet there's more to it than that. I've found all too frequently that changing one thing often leads to further complications in other areas. Typically that I didn't see coming or know enough about what I was doing to truly evaluate. Lots of builds have been completed with those brakes mounted that way, including the e-brake cable routing. Some other posts mentioned possible interference with the wheels. Just don't paint yourself into a corner.
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    Senior Member Paul2STL's Avatar
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    Mine are mounted in the stock position with FFR brake cables. The cables run forward and turn toward the center of the car after passing the shock. In the pic you can see my routing.

    IMG_4410.JPG
    MKIV #9122 Ordered kit 5/24/17 received kit 8/11/17 MK4 Base kit +,First Start 4/7/18, First Go-Cart 4/22/18, In gelcoat, licensed and driving 8/11/18. Coyote gen2, T-56, 2015 IRS 3.31, 17" Halibrand replicas w/Nitto NT555 G2, Withby Motorcars power brake kit W/Wilwood pedals, 04 Cobra front brakes, 15 Mustang rear brakes with mods, power steering. Paint Jeff Miller Da Bat, Lexus Spectra Blue Mica W/Toyota Silver Sky Metallic strips. Build thread: http://thefactoryfiveforum.com/showt...Paul2STL-Build

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    So to clear the air here...I think I discovered the reason why it is mounted that way and with a bracket. Turns out the caliper is not an authentic 2015+ Mustang part and physically will not bolt up to the stock mounting location on the knuckle (which is 2015+ Mustang part as well as the rotor) and must have that bracket. The bracket raises the caliper up and pushes it slightly out allowing proper placement on the rotor disc. I totally forgot to take pics while doing this experiment and have already torqued it back as per FFR manual. Maybe some of yall have received different calipers with your kit, but the ones I received with mine will not work in the stock location. Just providing an update and closure in my case...
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    25th Anniversary #9772 toadster's Avatar
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    Quote Originally Posted by Paul2STL View Post
    Mine are mounted in the stock position with FFR brake cables. The cables run forward and turn toward the center of the car after passing the shock. In the pic you can see my routing.

    IMG_4410.JPG
    what's your brake setup?
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    Senior Member CraigS's Avatar
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    I don't understand why FFR did any of this. I used the brakes that came w/ my salvage rear suspension when I did the 2015 IRS upgrade. So simple and they work great. I did need to grind my calipers a bit to run the usual 17in Bullit wheels.
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    Senior Member Paul2STL's Avatar
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    Toadster I am running the stock mustang brake calipers that came with my salvaged rear end out of a 15 Mustang GT. Just like Craigs said why FFR did any of this is unknown. The parking brake cables I got from FFR along with there cable adapter they make in house. It jus a 1/4" steel bent to like a L shape with holes to catch the cable end and to grab the ear on the parking brake lever.
    MKIV #9122 Ordered kit 5/24/17 received kit 8/11/17 MK4 Base kit +,First Start 4/7/18, First Go-Cart 4/22/18, In gelcoat, licensed and driving 8/11/18. Coyote gen2, T-56, 2015 IRS 3.31, 17" Halibrand replicas w/Nitto NT555 G2, Withby Motorcars power brake kit W/Wilwood pedals, 04 Cobra front brakes, 15 Mustang rear brakes with mods, power steering. Paint Jeff Miller Da Bat, Lexus Spectra Blue Mica W/Toyota Silver Sky Metallic strips. Build thread: http://thefactoryfiveforum.com/showt...Paul2STL-Build

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    25th Anniversary #9772 toadster's Avatar
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    ok cool - i noticed the drilled/slotted rotors - where are those from?
    Todd
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    Senior Member Paul2STL's Avatar
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    Quote Originally Posted by toadster View Post
    ok cool - i noticed the drilled/slotted rotors - where are those from?
    They are ELine series by R1 Concepts bought them on ebay and long with the fronts to match. Hope the link works.

    https://www.ebay.com/itm/For-2015-Fo....c100290.m3507
    MKIV #9122 Ordered kit 5/24/17 received kit 8/11/17 MK4 Base kit +,First Start 4/7/18, First Go-Cart 4/22/18, In gelcoat, licensed and driving 8/11/18. Coyote gen2, T-56, 2015 IRS 3.31, 17" Halibrand replicas w/Nitto NT555 G2, Withby Motorcars power brake kit W/Wilwood pedals, 04 Cobra front brakes, 15 Mustang rear brakes with mods, power steering. Paint Jeff Miller Da Bat, Lexus Spectra Blue Mica W/Toyota Silver Sky Metallic strips. Build thread: http://thefactoryfiveforum.com/showt...Paul2STL-Build

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