Floor mounted pedal box
Turbo Mini Forums

Hi all, I am looking to fit a floor mounted pedal box to my race car project.
What size master cylinders should i get for the front, rear and clutch?
I will be running mini spares 4 pots, drums on the rear and a non verto clutch.
The kit is advertised with 3x master cylinders (.625,.7 and a .75)
Anyone fitted one or know the sizes please?
Cheers, Alex

0.625F & .75R although you might need to go bigger on the rear or fit a limiter as I have had to to

On 5th Sep, 2011 Vegard said:
I stand corrected. You should know

you are missing the point :) smaller cylinders give more pressure

iirc you can get 7/8 rear cylinders from rally design

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

check the ratio on the box too,
5:1 / 6:1 etc

internationally known as "big" swede

You all are missing the point. There's no room for the master cylinders unless they are inverted

Line Pressure Comparison
The table below shows the range of bore sizes available and shows the % step up from the previous size and line pressure based on 50 lb pedal load and a 5 to 1 pedal ratio.


Master Cylinder Size mm/in. 14.00/
0.551" 15.00/
0.591" 15.875/
0.625" 16.80/
0.661" 17.78/
0.70" 19.05/
0.75" 20.638/
0.8125" 22.225/
0.875" 23.813/
0.9375" 25.4/
1.00"
Area sq in. 0.2386 0.2739 0.3068 0.3436 0.3848 0.4418 0.5185 0.6013 0.6903 0.7854
% step up from previous size N/A 14.8% 12.0% 12.0% 12.0% 14.8% 17.4% 16.0% 14.8% 13.8%
Pedal Load lb. 50 50 50 50 50 50 50 50 50 50
Pedal Ratio 5:1 5:1 5:1 5:1 5:1 5:1 5:1 5:1 5:1 5:1
Line Pressure p.s.i. (single cylinder) 1047.76 912.72 814.87 727.61 649.61 565.88 482.17 415.75 362.17 318.31

i bought a pedal box a while ago (wilwood) and it came with the master cylinders (2x tilton 1x wilwood)

after reading this i think i definately have the wrong ones :(

it came with a

0.75 for the clutch?
7/8" for the front?
1" for the rear?

and it says in the instructions its either 5:1 ratio OR 6.25:1 but im not sure on how to change it as there is only 1 hole in the pedals and only 1 slot in the box.

will this mean that the pedals will have to move further to give the same result as the smaller ones? AND will i also need to apply more pressure, if so. how much more pressure? is it a problem or not?

Thank you

Edited by Johnny on 8th Jan, 2012.

Does it not have a balance bar? This is the usual way to adjust the front to rear balance; effectively altering the the pedal ratio between the two cyliners.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

yes, it has a balance bar. but the drawing in the manual looks like it meant the pedal. i thought the balance bar was the bias?