This leads me to a discussion of the brake bias bar. It is very common in hot rods and even in our own Kit Car and Replica industry to see people place chokes on the rear brake line to control the brake bias. This is a very bad idea--especially in our cars that generally lack power brakes.
You see, you only have so much brake line pressure that is available in the system. If you limit the pressure to the rear brakes to get them to not lock up before the front brakes, then you are eliminating some brake line pressure that could effectively be used on the front brakes.
It is far better to mechanically bias the brakes toward the front of the car so you are then mechanically applying more pressure to the fronts than to the rears. Unfortunately, the original 427 and 289 Cobras did not have a way to adjust the brake bias mechanically. They had to do it by changing the master cylinder sizes front to rear.
In our dropped foot box cars, (where we designed the pedal box ourselves) we do run this type of a bias bar. When we do that, we actually put the largest size piston calipers available on the rear calipers so we can get the highest pressure possible on the rear caliper pistons. We then mechanically bias the brakes to the front so we can get even higher line pressure to them. That way, for a given pedal pressure, we get a higher line pressure--and hence, easier stopping of the car for the driver.
This will all become a lot clearer when I post a pic of the bias bar assembly.
Any questions are most welcome.
David
