Brakes Bias? Godzilla sized brakes

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garrittpwl

garrittpwl

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Great thread with a lot of good information, but I have to ask ... Why? Especially since a few posts back you say the car will be 95% street-driven. 14-inch top hats at 1.25 in thick will add a ton of unsprung weight and rotational mass, and unless you plan to run 345's on all four corners (yes, I know you can't), your brakes will likely far exceed the ability of the tires to stay stuck to the pavement.

(If you say "because it'll be cool," that's fine with me.) :)
So to make a long story short, I bought a parts lot off a guy that had a ton of stuff I wanted, particularly a rear end and torque arm setup. In that lot came these calipers and proper bracketry to make them work. I needed a brake upgrade regardless (car makes over 600, built 5.4 turbo on e85). My stock single pot steel 96 calipers were not cutting it. Since I had these calipers for almost nothing, it was worth it to use them for the "cool" factor. Pads arent that bad for it being a 6 inch pad. 150/set for Hawk HPS street pads. The car will also see some R888R's this year and may get a spirited day or two at a local road course. Now I don't have to fear anything but keeping my engine cool on those days. Also because when I show up to a cruise in with brake rotors filling the front AND back, its cool as fuck hahaha.
 

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Is the 14” rear setup an actual kit, or using fabricated brackets to mount a front setup in the rear?
 

white95

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Great thread.

When I had the simple, Baer +1 13” rear rotor kit the bias was always heavily to the rear. Further adding to the problem (that I created) was using 43mm (Taurus) rear calipers and track day pads. Switched to stock pads and it was still rear biased. Initially was going to add a Wilwood bias adjuster but ultimately switched to stock rear brakes/pads. Only then, did the car stop “evenly”.

My total set up consists of 97 Cobra hydroboost, 14” rotors and 44/40 Brembo calipers aaaand no ABS (another misstep)
 
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garrittpwl

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Is the 14” rear setup an actual kit, or using fabricated brackets to mount a front setup in the rear?
There is no kit for these calipers on an SN95. The brackets I have were all custom made by the previous owner who was the owner of the parts lot that I bought. He had a pretty wild Sn95 that he autocrossed, even had SLA front suspension. I was able to buy all his extras when his family sold out the remnants of mustang parts. The car was sold some years ago after the owner passed away. The amount of brackets I have that are the same size tells me that when he had them made, he had to buy a full order to get them done. I have enough caliper brackets to field an entire nascar race.
Great thread.

When I had the simple, Baer +1 13” rear rotor kit the bias was always heavily to the rear. Further adding to the problem (that I created) was using 43mm (Taurus) rear calipers and track day pads. Switched to stock pads and it was still rear biased. Initially was going to add a Wilwood bias adjuster but ultimately switched to stock rear brakes/pads. Only then, did the car stop “evenly”.

My total set up consists of 97 Cobra hydroboost, 14” rotors and 44/40 Brembo calipers aaaand no ABS (another misstep)
I have no ABS as well, but my car came that way from factory. Obviously with just the stock proportioning valve, I expect to be well over bias'd to the rear. But I plan on dialing that back with the wilwood valve in addition to the OEM one. Haven't got a chance to see what my output pressures are yet as I threw my back out over the weekend and I'm letting it recover.
 

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Braking effectiveness is generally limited by the tires, not the brakes. 90% of braking is in the front because, physics.
 

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I am just surprised as anyone I know that takes if off swears that they can do such a better job as if they came off the F1 circuit last year winning the championship.

I know modern ABS is much much better due to faster processors and solenoids, but the 99-04 ABS wasn't too bad in my opinion. I've autoXed with it and didn't find it to be a burden. Of course i know HPDE is a different animal. I've had a GT500 on track and absolutely thrashed it and while you could tell the nanny aides were there, they were definitely not overbearing.
 

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I got 3 laps in a 2021 gt500 and hell yes that sucker can stop, turn and go for that matter and all the while with a glorious sound.
 

white95

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I know modern ABS is much much better due to faster processors and solenoids, but the 99-04 ABS wasn't too bad in my opinion. I've autoXed with it and didn't find it to be a burden. Of course i know HPDE is a different animal. I've had a GT500 on track and absolutely thrashed it and while you could tell the nanny aides were there, they were definitely not overbearing.

The newer, four channel ABS is what I’m going back with.
 
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garrittpwl

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Update* I think I've got a decent starting point. Gonna check the "mid range" brake pressures when I get someone to sit and hold the pedal at different levels.

With the factory non.abs valve in place and a wilwood valve on the rear line set to minimum, my pressures full lock up ar 1250ish front and 400ish rear. 1650psi total for a front/rear bias of 75.7/24.3. Since the caliper size, pad and rotor size are all the same, this is my only variable. I'm gonna dial it in a little so it gets closer to 70/30 and then check pressures in the lower ranges too but I think I've accomplished what I was aiming for.

Video here showing the readings
 
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garrittpwl

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Interesting. When will you be driving it to see how it feels?
Soon. As you can hear in that video I still need to button up the exhaust. I'm not a bullhorn bumper dump kind of guy.

Also still need to reset my suspension and dial in the axle/panhard bar stuff
 

Mustang5L5

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interesting the amount of reduction you got through the two valves in series. Have you driven it yet?


Edit: nevermind saw your last post.
 
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garrittpwl

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interesting the amount of reduction you got through the two valves in series. Have you driven it yet?


Edit: nevermind saw your last post.
Seems to drive well. Brakes work very nice, pedal is a hair softer than oem but I relate that to moving more fluid. Managed to lock up the right front a few times while testing them. Bias adjustment sees to be working as it should. Dialed in some rear and managed to lock up the right rear. Took the adjustment back out hahaha.
 

lwarrior1016

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Seems to drive well. Brakes work very nice, pedal is a hair softer than oem but I relate that to moving more fluid. Managed to lock up the right front a few times while testing them. Bias adjustment sees to be working as it should. Dialed in some rear and managed to lock up the right rear. Took the adjustment back out hahaha.
That’s awesome! I’m really glad to hear that.
 

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