master cylinder sizeing

[fasterpatrick]

I want to use triple master set up for my car and would like to know how to size the masters for the brakes, I will be using GM metric front calipers and T-bird rears to start with and will be upgrading the brakes down the road. Lets get the car on the road first, then tweak it. Patrick

[Clois Harlan]

Patrick,

I had the exact same setup on my Cobra for awhile. I used a 3/4" master cylinder on my fronts and my clutch and a 7/8" master cylinder on my rears with a proportioning valve mounted under my dash to adjust my rear brake bias. I worked exceptionally well for me. Even if at some point you choose to go to Wilwoods those same master cylinders should work fine for you.

Using the 3/4" MC on your clutch I am assuming you are running a hydraulic clutch mounted to your transmission inside your bell housing and not a slave cylinder mounted on the side of your transmission.

Clois

[mickmate]

I just did a google search on cylinder sizing. Some useful info on http://www.outlawdiscbrakes.com/faq.html
As Clois said your sizes look good at 3/4, 3/4 and 7/8" there's another link I found which I'll also post that verified what the 3/4" master will go up to for slave sizes.

[mickmate]

Here http://factoryfive.com/table/whatsne...akeadvice.html

[fasterpatrick]

Okay let's see I'm working with a front with area of 4.43" and rears with 2.23". Why would you run with the larger cylinder for the rears. Oh and I will be useing an external clutch slave (have had bad things happen with the internal ones and they are a b#ch to work on.).Patrick

[392cobra]

Patrick,
Here is a link to Tilton.Fill out all the info and they will let you know what they recommend.They do give good advise.

http://www.tiltonracing.com/content.php?page=faq&view=9

[FIA-ERA]

Hey Patrick,
I have a Wilwood triple break set up I can't use. It is part number 340-4828. I bought these and tried but they won't fit for my application. If your interested let me now. They are brand new and never been fitted just looked at. Triple m/c, Reverse mount/5.1. They are nice. No master cylinders. Was going to use 1' up front/7/8" rear/ 7/8" clutch. Tell me what you think! Love the build up! Matt.

[jarendall]

I used the Wilwood masters with the remote tanks, used the small tanks, the kits come with both large and small tanks, there was no way to fill the masters on my car using conventional masters

[fasterpatrick]

well I found a really good deal on ebay for a pedal setup with masters forward mount. with 7/8 masters for the brakes and 3/4 for the clutch. Ya so what. But what I really found bizarre was the info I received from tilton and their form check this out.Patrick,

With your combination, we recommend a 13/16" front and a 1-1/8" rear master.

Regards,

Ehren VanSchmus
Tilton Engineering
ehrenv@tiltonracing.com
Vehicle Info


Make: custom
Model: Cobra replica

Front Brake Information

Number of pistons within each front caliper: 1
Are pistons on one side or both sides of caliper: one

Diameter of pistons on one side of caliper (list all):

Piston 1: 2.38 in
Front rotor diameter: 11 in

Rear Brake Information

Number of pistons within each rear caliper: 1
Are pistons on one side or both sides of caliper: one

Diameter of pistons on one side of caliper (list all):

Piston 1: 1.73 in
Rear rotor diameter: 10.5 in

General Information

What is the motion ratio of your brake pedal (5.5:1, 6.2:1, etc)? 6.25:1
OR
If using a Tilton pedal assembly, please provide part number: -
Vehicle weight (with driver and fuel): 2200 pounds
Vehicle Weight Distribution (with driver and fuel): 55 / 45
Vehicle wheelbase: 90 in.
Front tire diameter (outer): 26 in
Rear tire diameter (outer): 26 in
What is the vehicle being used for (street, road racing, circle track, drag,
etc)?: street/ auto cross