calculating rear brake needs>>I hope

[instructorbill]

trying to use Brakemath.xls, but have hit a roadblock.

It's a great spreadsheet but I'm not able to calculate the rear brake needs using this spreadsheet because its calculations/fields are set up for rotors, calipers, and pads (not for drums, wheelcylinders, and brake shoes)

And so I beg for information.

Anybody running 320i drums on a race or race prepped street car? What diameter master are you using for the rear brake circuit? I know that I'll want to change that later but for now, I'm preventing project creep (which is critical if I want to melt tires in 2008.)

What pedal ratio do you have? (I calculate the stock ratio to be 4.29:1-- is my math right? Those in the know will surely speek up) I plan to just relocate the stock pivot to the brake arm itself and run it at 1.2 inches from the center of the pivot arm for a ratio of 6.25 This arrangement looks like the height will work out fine and the masters/plumbing/bias will clear the remoted clutch assembly with ease.

[JackF]

I don't know the math, but I'm real happy with the brakes on the turbo. Basically a CS front with a 250mm rear. Perhaps check realoem for some turbo part numbers.

[Guest Anonymous]

Assuming a big brake kit on the front. We use the 250mm drums with a 22 mm wheel cylinder and a proportioning valve. For the street a 19mm wheel cylinder is the way to go.