Brake Math Spreadsheet

[Legacy777]

I may have posted this before, but I've had some time to go through the spreadsheet and clean things up, and make quite a bit of improvements. The biggest being a 'Brake Torque Calculator'. Let's say you want to swap some WRX brakes onto your 90 Legacy. Choose your car from the drop down menu, and the WRX as what you want to go to, and the calculator will spit out the percent change in brake torque and whether the shift is frontward or rearward.

 

If you don't see your vehicle in there and have information on your car, please let me know and I will add it. Likewise, if you see anything that looks incorrect or suspect, please let me know.

 

http://www.main.experiencetherave.com:8080/subaru/techinfo/brakemath.xls

[NoahDL88]

Can i just say that you rock for bringing this to us, and whoever made this rocks X2.

 

Hmm, now what should i do to the OBS?

[Legacy777]

Welcome.

 

..and whoever made this rocks X2.

 

I made it

[NoahDL88]

Cool, then i can complain to you that you don't have the early model impreza's in there, unless i totally flaked. :cool:

 

 

I was thinking that you should also have the EA series on there, but then i realized that it would be a 100% improvement with any EJ part, so i guess it wouldn't be necessary.

[jamal]

The biggest being a 'Brake Torque Calculator'.

 

AWESOME!!

 

Hey now all you need is to put in the coefficient of friction for all the different pads available.

 

Here's my pending change:

90-94 Legacy n/a front brakes with stock pads

-> WRX front brakes with performance pads

= 60.28% torque increase.

 

90-94 Legacy n/a rear sedan brakes with stock pads

-> H6 rear brakes with performance pads

= 60.22 torque increase.

 

total 0.06% increase in forward brake bias.

 

I just need that guy to ship me my rear brackets.

 

Oh, also, for a wagon prop valve would I just add 13% to the rear?

[Legacy777]

Cool, then i can complain to you that you don't have the early model impreza's in there, unless i totally flaked. :cool:

 

 

I was thinking that you should also have the EA series on there, but then i realized that it would be a 100% improvement with any EJ part, so i guess it wouldn't be necessary.

 

I've got the 95 impreza in there. I don't have other ones because I don't have factory manuals. However the brake rotor & caliper piston size is more then likely the same as one of the Legacy setups.

[Legacy777]

AWESOME!!

 

Hey now all you need is to put in the coefficient of friction for all the different pads available.

 

Here's my pending change:

90-94 Legacy n/a front brakes with stock pads

-> WRX front brakes with performance pads

= 60.28% torque increase.

 

90-94 Legacy n/a rear sedan brakes with stock pads

-> H6 rear brakes with performance pads

= 60.22 torque increase.

 

total 0.06% increase in forward brake bias.

 

I just need that guy to ship me my rear brackets.

 

Oh, also, for a wagon prop valve would I just add 13% to the rear?

 

You may run into issues with the pedal travel. I know I didn't really care for how things felt when I swapped things over. If you have ABS, you should be fine because the MC is larger. If you don't have ABS, you may want to look at a 4-port 1-1/16" MC if you don't like how things feel. I'd only do that if you don't like how things feel.

 

I wouldn't mess with the prop valve until you get everything in, and see how you like it. It may be perfectly fine.

 

The 13.25 percentage increase with the wagon prop valve is only seen when above the split point of the wagon prop valve. The percentage increase tapers down as pressure increases. If you look on the split point data sheet, and the far right column, there is a percentage number. That's the percentage increase from the sedan valve.