brake issue
 

having issue with brakes on a 2400 pound super gas car, 4 wheel aerospace disk brakes, brake pedal has literally only 2 inches of travel at most and pedal is incredibally hard but does not hold car in beams when footbraking the car,it takes ungodly pressure to hold car at all when you get on converter, changed master to a new wilwood style, what is the right bore size for a master cylinder in this application, i beleive it has 1 1/8 on it now ,any ideas

Re: brake issue
 

Has it always been this way or is this a new problem?

Re: brake issue
 

Best bet is to use a pressure gauge to see if there is a problem. Basic hydraulics, the bigger the MC bore the less pressure but more volume. The smaller the bore MC the greater the pressure the less the volume. Also pedal ratio needs to be 6:1, 12" long brake pedal the MC rod needs to attach 2" from the pivot.

Re: brake issue
 

http://www.markwilliams.com/braketech.aspx


A lot of good info about brakes in the MW link above..

I have used Aerospace brakes and they worked very well....on a dragster.

Pedal ratio and MC sized properly are the things to look at...

A bad MC or caliper piston not moving might be possible...

Re: brake issue
 

Sounds like to me that you need a smaller bore mc.
This is probably worth about what you paid for it.
Pete

Re: brake issue
 

A few years ago I changed my brakes from drums to Aerospace 4 wheel discs. I used all their parts including the M/C. It never had a good brake pedal. I added a 2lb valve and still I always had the same issue. Lots of brake travel and the same as you. Nothing until about 2 inches from the floor would there be any brake pressure. And if you stood on them they would almost touch the floor. You could pump them and then the pedal would be at the top but after a few seconds brake travel would be back as it was. Several calls to Aerospace accomplished nothing. Even bought a new M/C from them with no improvement. 2 years or so ago I was racing at a divisional and got a little aggressive with the brakes on top end. Car went side ways and just about rolled the car and hit my opponent. Enough is enough. That fall switched to Lamb brakes. There is no comparison. Lots of brake pedal and no issues.

Re: brake issue
 

Aerospace....that sez it all.....

Re: brake issue
 

Jim ,you should recognize this problem from your own experience on your Stocker .
Pedal ratio is probably too low for the 11/8"cylinder .
A 6 to1 ratio is even a little low for the large cylinder ,I usually use 7 to 1 for the 1 1/8" and 6 to1 on the 11/16" or 1 1/32".
Best to test the pressure at the caliper with a gauge , first hit should deliver a minimum of 900 #.
As was mentioned , Aerospace brakes leave a LOT to be desired . ...I have helped several racers having issues with them .

Re: brake issue
 

Have aerospace all the way around my stocker. No issues at all with 1 1/16 Willwood master. The pedal is soft does pump up a little but not uncomfortable, for staging there is plenty of travel to hold footbraking.

Re: brake issue
 

I have Aerospace brakes on my car and they work perfectly. It takes a bit of work to get them installed properly. The have to be exactly square to the rotors or you will be having the issues that are being described here. I have a Mopar style M/C on my car that I used with the drum brakes before I put the disc brakes on. Not sure of the bore size. Mine stops really good. I have to be careful not to hit the brakes real hard just set my toe on the pedal and it stops real nice.
I was at the gators this year in the staging lanes during first round for Super Stock. The owners of Aerospace came up to me while I was suiting up and thanked me for using their brakes and fuel pressure regulator. They handed me their card along with a crisp $100 bill and said to call if I had any needs or issues. Good people and good product for reasonable cost.