Brake system design formulas...?

[Homemade WRX]

Hi, I'm having a hard time finding formulas for designing brake systems. I was wondering if anyone had any info or any particular books that were of any great help to them.
Thanks, Micah

[audi fan]

The Brake Handbook from Fred Puhn is an excellent place to start. I designed the brakes for the '05 UoG Car using it and they work like a charm. I entered all the formulae into an Excel spreadsheet and played around with master and caliper bore sizes to see what would work best.

Chris Quinke
Gryphon Racing '04, '05

[Homemade WRX]

Originally posted by audi fan:
The Brake Handbook from Fred Puhn is an excellent place to start. I designed the brakes for the '05 UoG Car using it and they work like a charm. I entered all the formulae into an Excel spreadsheet and played around with master and caliper bore sizes to see what would work best.

Chris Quinke
Gryphon Racing '04, '05

thanks for the help...I will have to find it.

[jack]

uh..like..carroll smith, dude...

and..like..do a search..all the equations are probably on this forum somewhere

...uh ..yeah..

[RaID]

Originally posted by audi fan:
The Brake Handbook from Fred Puhn is an excellent place to start. I designed the brakes for the '05 UoG Car using it and they work like a charm. I entered all the formulae into an Excel spreadsheet and played around with master and caliper bore sizes to see what would work best.

Chris Quinke
Gryphon Racing '04, '05

definately check out this book easy to follow and covers a wide range on info

i picked up mine on Amazon for $5 second hand,
designed brakes that did job quite well

[rjwoods77]

Raid,

Does Fred book include stuff about kinetic energy into the rotors, heat loss and all that stuff. We wrote our one spreadsheet using the same equations out of a different book and we are now trying to figure out what size rotors(diameter and thickness)will be suitable for the job.

[B]

I'm in the same boat.... need to find out what size rotors to use....

If anyone knows how to calculate what dimensions required to disipate the heat given the braking conditions and material properities then you'd b a life saver!!!

Brett

[Homemade WRX]

the searches I have been able to do have yeilded some help but I'm going to go ahead and buy the fred puhn book, and see if we have anything on it in our carroll smith collection at the lab.
take it easy, Micah

[John Bucknell]

As a former brake engineer, the books out there don't tell you how to figure out the heat capacity necessary for a good brake. Most make the mistake of designing for a single brake apply, and not for the stabilized temp. How to find the stabilized temp to design to?

The german auto magazine Auto Motor und Sport does a test on all the cars that come through that I think is a good indicator of how to size brakes. They run the car up to 100 kph (62 mph) and do a stop with the brakes cold and record stopping distance. Then they let the brakes cool down again, then do max effort 0-100-0 kph ten times in a row and compare the stopping distance first stop to last. A car that has no fade in that test is effectively race quality (not Le Mans race-quality, but sedan racing). In a FSAE car, you would spike about 100 kW into the brakes every 5 seconds during that test. Remember that radiant heat transfer is your friend and figure out whether your friction material will function in a brake that is glowing and maybe it is now about the right size. Not hot enough to glow isn't that much heavier, and considerably easier to work with (ie it won't start melting nearby components). This isn't everything to be sure, but it should give you a feel for the duty cycle.

[Homemade WRX]

thanks for the helpful testing method...I would like to see how our past car holds up