MROE BRAKE QUESTIONS

What size master brake cylinder bore should be used: 3/4 inch, 1 inch? Shold fronta and back be he same size? Will have 11.5 inch discs front and 10 inch rear. Should brakes be boosted? cb
 
Chip, Some folks prefer the boost, some not. Depends upon personal preference. For racing I'd say not, for tooling round town and maybe letting the wife drive, I'd say yes to the boost.
Regarding the master cylinder, a lot of guys use a Tilton or Wilwood pedal box which utilizes two master brake cylinders, one for front, one for back with an adjustable bias between the two. Master cylinder size requirements are dictated by caliper requirements (number of and size of "pots"). There has been a lot of experimenting regarding brake set up. Best thing to do is find a similar car with a good system and utilize the same components. (Like I have done!)
Brian
 
Brian: Thanks for the info: What specific set up are you using? (rotor size, pots, bore of mastercylinders, same/different bore front back). I belive what you are saying about front/back bore is to use the same size and use the balance bar to adjust for F/Rbias. c
 
Chip there is no standart answer to your question. It depends on the pedal ratio you have. If you want to be not boosted you need 5 to 1 or better. Your master cylinder size has to be integreted with your calipers piston area. Companies like Wilwood or Baer can advise you. I think you would find the upgraded brakes used on the Cobra R or similar very good if they would fit your spindle choice. I have Datsun 300ZX four pot alum. calipers and 11 5/8 discs on my front and 12" Corvette discs using a Mitsubishi Starion caliper and emergency brake on the rear. I find they work well on the track and street but I use boosters because the standard GTD pedal box has only about 3 1/2 to 1 ratio. I have to work within a 15" wheel.
 
I have a Matlab program that you are welcome to (if you have Matlab). I wrote the program a few years ago to study the braking system. If you do not have Matlab I can run the program with your data and give you some recommendations. It is setup to use a dual master cylinder assembly (like Tilton or wilwood). I need to know everything about your setup.

Wheelbase, cg height estimate, front caliper number of pistons and diameter, rear caliper info, front rotor diameter, front pad radial height (so I can calculate max and min diameters for the pad contact area), same info for rear rotor and pad, pedal arm ratio, weight of vehicle, design stoping rate (eg. 1.0 g's)

What comes out is all info relating to brake application at given stoping rate. It will estimate the weight tranfer, front/rear brake bias, forces on pedal and tire, brake pressures, etc.

It would give you a very good starting point then drive the car and see how it compares, etc. Obviously no warrentee implied or written
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