Help !!!!Brakes & Master Cylinder

[priobe]

rdorman,

I agree with you about the plating possibly being the problem.

Jerry,
Thank for the info and its funny you should say that. keep reading.


I contacted Wilwood and asked them how is it they came up with the solution to my problem. They told me that the setup which I have is the exact setup used in Superformance cars and it works fine.

Ok.....

I contacted Tilton and spoke to the Lead Engineer. I ask him the same question and why is it that it differed from Wilwood. He responded by saying if you contact Wilwood and ask them for a Master Cylinder setup they will almost always respond 3/4 front 7/8 rear regardless of the car.

He told me that the reasoning for the 1 1/8 bore size to the rear is because I am running a large rotor and larger pistons for the rear caliper. At that time he mentioned that he bets that Wilwood did not ask for any specification on my vehicle, which is true. He told because of the large multiple piston size in the rear combined with the large rotor that it will not take much to lock up the rear brakes. He said possibly 250-275 psi to lock the rear and 400-450 to lock up the front.

I am feeling confident that Tilton's suggested method is the better of the two.

I am not sure if this is the solution to my problem or if it is because I had the cylinders plated. By removing the plated cylinders and installing the 7/8 front and 1 1/8 rear, I will eliminate both possiblities.

Tilton also suggested not to run anything above the Wilwood 570 brake fluid because it will eatup the seals over time. He went on to explain that if you are using the car for racing then it does not mater because you should be rebuilding the masters and the calipers more often.

Final result is to order 7/8 and 1 1/8 bore from Tilton. "With out having them plated"

But first I will try to bleed the system individually one last time before I place the order.

Coud some Superformance guys comment on you brake setup please!!!!

[rdorman]

I played with both the Wilwood recomendation and the Tilton one. Both will bring you car closer to balanced bias then you are now (bias bar centered of course). One will simply result in about 15 pounds more pedal force then the other. Tilton will be right about 75 pounds of force which is the commonly recommended starting point for a race car setup up. After that comes driver preference and style of course. Personally, I have found 75 pounds nice in race car where you are strapped in well in a seat with little padding that does not move around much... haven't liked it much in the typical cobra.

The Tilton combination is well balanced (all looking at a 1g stop and a 20" CG height)). A slight forward bias of about 2% while the wilwood is more like 16% rear (about 32% rear now). Rear would need tuned out. Other combos could be 5/8 and 13/16 (4% front bias), .7 and 7/8 (3% rear) and 13/16 and 1" (6% rear). Ordered in the rate of increased pedal effort from the 5/8 (40 pounds or so) to the Tilton combo of about 75 pounds.

Regardless of what you do, can't wait to hear the results.