Master Cylinder Recommendations

[Bill D]

I need two brake and a clutch master cylinders for my car. Very tight space of 4.75" to fit. Need to be remote reservoir type.

Brakes are 94 Mustang GT in the front and 94 Mustang Cobra in the back

Thanks
Bill D

[Rick Parker]

Bill: To properly size the M/C you must provide the piston diameters in the calipers, the number and of pistons in each caliper. You then factor in the pedal ratio and approximate weight of the car and rotor diameters. Wilwood, Tilton and other brake suppliers can help determine what diameter M/C is needed with the above info, don't guess at this do it once, do it right.

From Wilwood website:

What master cylinder bore size do I need?

A:

The master cylinder bore size that you need is dependent on several variables. Choosing a master cylinder bore size begins with defining how the master cylinder will be actuated, manually or with the assistance of a booster, either hydraulic or vacuum operated. Once you have decided on how the master cylinder will be actuated, the information below can be used as a guideline for selecting the right master cylinder. Keep in mind that auto manufacturers have put many years of experience and a lot of testing into determining the right combination for a given car. When building a custom car with changes to the suspension, brakes, tires, and weight balance; you too may need to do some testing to determine which master cylinder is right for your vehicle.

The combined piston area and piston volume of your calipers and the pedal ratio, are two of the primary considerations. Whether the system is boosted or not is another consideration. Remember that a larger master cylinder bore produces more volume and a smaller master cylinder bore produces more pressure. To determine the appropriate master cylinder bore for your specific application, review Wilwood's Tech Tip Guide. You can also contact a Wilwood Sales Technician at 805-388-1188 or email Sales/Tech Support.


Here is info for Tilton:




http://tiltonracing.com/product-category/brake/

[mr bruce]

Wilwood High-Performance Disc Brakes - Master Cylinders

[YerDugliness]

Bill, you don't say what size/design brakes you have (other than that they are Mustang/Mustang Cobra factory pieces), but if my experience can be of any help, here it is.

My calipers are Wilwood Dynalites...4 pistons per caliper. The rotors are 3/8" thick, not ventilated. I had a Ford style master cylinder on it and it was leaking into the cockpit, so it had to go. I posted a thread and the issue that confounded me was the pedal ratio (my replica has a home-made pedal box and the pivot point is up too far to be able to get a good measurement.

With all that was going on, it was obvious that I had to take a shot in the dark. I had not been happy with the pedal feel even before the MC started leaking...l really wanted to use the Wilwood power brake system, but like you there was not adequate room between the firewall the the fenderwell, so power brakes were out of the question.

In the end I switched from a Ford style master cylinder, which has one large reservoir and one small reservoir, to a Corvette style master cylinder, which has equal size reservoirs for the front and rear systems. My "leaky" master cylinder had a 1 1/16" piston size, so I dropped down by 1/8" to a 15/16" piston in an effort to get more stopping power with less pressure on the pedal.

I am very satisfied with my choice, the brakes are rock solid and there is no fade. Since the front and rear calipers are identical, the choice to switch to a 'Vette style master cylinder was the correct choice.

I had to approach it in a trial and error manner, I just got lucky with the first trial. I notice you'll be using remote reservoirs...that thread Mr. Bruce posted shows a very small master cylinder with the fitting for the hose to the remote reservoir...looks very small to me. If you get to choose from a variety of piston sizes, I found out that the smaller the piston size the less pedal pressure is required to get the same stopping power.

Of course, if your brakes use larger pistons than my Wilwoods, or more pistons per caliper, you may need a larger size piston.

Good luck...I've been watching your build thread and this is going to be one incredible car when you're done.

Cheers!

Dugly

[PSB]

When I "upgraded" my brakes from power to manual, I called Wilwood's tech line and told them my setup. They were very helpful and their recommended master cylinder sizes worked great.

Pete

[Bill D]

Thanks guys. I need to get more information on my setup based on your recommendations