The bottom line is, if the stopping power of a car needs improvement, or if there’s a need to reduce the pedal effort, several options are available: (1) Decrease the master cylinder bore size; (2) Increase the pedal ratio; (3) Increase the wheel cylinder bore size. If the pedal ratio is increased, there will be more travel at the master cylinder piston. If the master cylinder bore size is decreased, the piston has to travel further to move the same amount of fluid. Typically, a master cylinder has approximately 1-1/2-inch to 1-3/4-inch of stroke (travel). The idea here is coordinate the pedal ratio with the bore size to arrive at approximately half of the stroke (roughly 1-inch) in order to make the brakes feel comfortable, and of course, to bring the car to a grinding halt.
|This manual master cylinder is one of the most common you’ll find in modified applications. It is based upon a Mopar configuration, and is sold by Mark Williams Enterprises and others. These master cylinders are available in at least two different bore sizes: 1.00-inch and 1-1/8-inch (a 1-1/32-inch bore cylinder is also available from some sources. This is very close to a 1.00-inch assembly, and it's sometimes called that). They’re manufactured with an aluminum body along with a relatively large capacity plastic reservoir with dual outlet bores (which correctly face the driver side fender when mounted in the car).|
|The Mopar master cylinder has one shortcoming: The size of the outlet fittings. The front fitting is a 9/16-20-inch Inverted Flare while the rear is a 1/2-20-inch Inverted Flare. They’re not common. Lamb Components offers a solution. Lamb manufactures special adapters specifically for these master cylinders that allow an easy hook up to #3 A-N fittings.|
|Look carefully at this piece: It’s a pushrod retainer engineered into the M-W master cylinder. The purpose? It positively retains the brake pedal pushrod. That means the pushrod can’t fall out if the pedal goes over center. And don’t laugh. It happens more regularly than you might think with modified cars.|
|The typical Detroit pedal assembly looks like this. This vintage Nova hanging arrangement is designed to accept the brake pedal assembly, and if equipped with a clutch, that too.|
|If you take a close look at this pedal, you can see two different master cylinder pushrod mount holes—one is for a booster-equipped application, while the other is for a non-boosted brake arrangement. For a late model, non-boosted manual application, many fabrication shops modify the pedal assembly by creating a mount that is higher (up the pedal) than the original. By moving the mount position higher, the pedal ratio is improved.|