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Dual master setup FD HELP PLS

Old 11-19-07, 04:49 PM
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Dual master setup FD HELP PLS

Hi

I have a track FD that I run in a UK race series. Got car down to around 1000kg so quite light now. And I have fitted KAD 6 pots calipers all round smaller 6 pots at rear . front discs are 365mm rears are 330mm. with a bias valve.

I want to get ride of the std Master / servo setup and go with a non servo assit dual master setup. didn't won't to go pedal box route but I would do this if I can't get any results here.

I have done a search but they isn't much to go with so any help would be great

Thanks Guys
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Old 11-21-07, 02:15 PM
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I believe a pedal box is the only way to achieve what you want. I installed Wilwood's overhang pedal box with tilton 75 series master cylinders. It was a bit of a job, but I'm very happy with it.
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Old 11-26-07, 04:56 PM
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the OEM FD pedal ratio is, AIR, approx 4.2 to 1 which explains why, if you disconnect the vacuum assist to the brakes you won't have enough leg to stop the car. ask me how i know.

you will need approx 6 to 1 and can only get it by doing a pedal assembly install. Wilwood-Tilton-AP. of course the big dividend is having the cockpit adj bias bar which any really fast racecar needs.

there has been a force multiplier bracket that bolts to the firewall and supports a front and rear brake cylinder but it adds stroke to the pedal and is bulky in the engine compartment.

i think the better deal is to go w a pedal assembly.

Ikestaa, any pics? i, as well as many others, are interested in your setup.

hc
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Old 11-26-07, 05:46 PM
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Overall, I really like the setup. I had to run smaller masters to get the line pressure I need, but I've got it where I want it now. I run an adjustable balance bar and a proportioning valve to adjust it on the fly. Pedal feel/modulation is great. I don't like power brakes because you have to modulate with pedal distance vs. pedal pressure. I also wanted to build more of a drivers car, thus the desire to get rid of power brakes/ABS. Now I have a short, firm pedal for both brake and clutch, and it's a treat to drive.

Things I would change - I'd seriously look in to running a floor mount vs. the overhung setup I have. The location I have it in required me to remove some sheet metal, whether or not this is structurally significant I'm not sure, but it has certainly made me wonder. Additionally, because the masters are mounted so high, the resevoir is not very high above it. This makes for slow filling of the masters, which really isn't that big of a deal. The location I have it in now also makes it difficult to service the cylinders, which will need to be rebuilt periodically. I didn't run the floor mount because I mocked up a wood model, and it seemed as though it would be a tough fit. In hindsight, I wish I would have put in the extra effort to make it work.







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Old 11-27-07, 08:47 AM
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thanks for sharing.

i am going to revisit the brake system this winter. currently i have the RacingBrake setup w 13 X 1.26 inch front rotors, 4 pistons upfront and the relocated stock caliper w the RB rear 12.7 inch rotor.

nice, but not enough rear brakes. i will be switching to a 4 X 1.125 piston caliper on the rear. since i am very happy w the pedal travel i may retain the stock pedals and add a cockpit adj rear brake proportioning valve and keep the power brakes.

if i don't like the pedal travel w the new rears i may find myself w new pedals.

hc
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Old 11-27-07, 11:49 AM
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Originally Posted by howard coleman View Post
there has been a force multiplier bracket that bolts to the firewall and supports a front and rear brake cylinder but it adds stroke to the pedal...
A 6:1 pedal assembly also increases stroke - it's an inevitable result of the greater leverage. For that matter, increasing the hydraulic multiplication (e.g. smaller MC) gives more pedal travel.
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Old 11-27-07, 11:53 AM
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fwiw, Stoptech just added a technical article on dual master setup:

http://www.stoptech.com/tech_info/te...e_papers.shtml
http://www.stoptech.com/tech_info/Pe...ster-Guide.pdf
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Old 11-28-07, 02:23 PM
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I have since been in contact with KAD and have sent them the pedal assembly and some engine bay measurements, they believe it can be done and have also mentioned the ratio stuff you guys have talked about.

Thanks so far keep you posted
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