Jamar Performance Forward Swinging Brake / Clutch Pedal Assembly With 5000 Series Reservoirs Chr Arm

Dimensions:
• Mounting surface to end of pedal: 9"
• Total length: 12-1/2"
• Pedal pivot to center of pedal: 7-1/2"
• Pedal pivot to center of MC push rod: 1-3/4" (see note below)
• 7.50 ÷ 1.75 = 4.29:1 Ratio (see note below)
• Pedal pad: 2" wide 2-3/4" tall

Using the top hole would get you a higher ratio and therefor more leverage and higher pressure (971 PSI versus 1292 PSI using a 3/4" master cylinder) but you will have less volume.

When selecting master cylinders, you'll notice with a smaller bore, you get more pressure but less volume. With a larger bore you get less pressure but more volume. You need to make sure that you have enough volume to supply your brake calipers, but at the same time, enough pressure. This pedal assembly was intended for 2 wheel rear brakes only on a Baja bug, buggy or sand rail with brake drums or small 2 piston calipers.

A 5/8" clutch master cylinder gives you a softer pedal feel but you have to push the clutch pedal further down. The clutch pedal will move about the same distance as a stock beetle clutch pedal if you use a 5/8" master cylinder. A 3/4" clutch master cylinder gives you a harder pedal feel but you don't push the clutch pedal down as far as the 5/8" master cylinder because you're moving more fluid volume. The 11/16", for most people, is a happy medium.

For each pedal, here is an example of the math. Pushing the pedal with 100 pounds of force, a 4.29:1 pedal ratio and a single 3/4" bore master cylinder:

Pedal force at master cylinder:
100 lbs x 4.29 ratio = 429 lbs

11/16" master cylinder area:
A = π r²
A = 3.14159 x 0.375 x 0.375
A = 0.4418 in²

Line pressure:
429 lbs ÷ 0.4418 in² ≈ 971 PSI

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