Braking calculations

[WALDOPIPE]

Hey Guys,

In our first year we had a very heavy car so in order to that we had to use a very big braking system but it really worked very well; but as a second year team we are trying to reduce as much as posible the weigth of the car and the sizes of all the pieces.

Just wondering if anyone has any tips on how to perform calculations to determine suitable rotor sizes front to rear regarding: load transfer, tire friction coefficient, deceleration G's, rotor coefficients, clamping force/master cylinder sizes etc etc.....


I have like a month looking some information on internet but its really hard to find some ecuations that helps.

I would be very thankful if somebody could help me to find or already have information about this topics.

best luck for all your teams.

Oswaldo Leon
Team Formula Sae UCV
Caracas, Venezuela
Engineering Excellence

[WALDOPIPE]

Hey Guys,

In our first year we had a very heavy car so in order to that we had to use a very big braking system but it really worked very well; but as a second year team we are trying to reduce as much as posible the weigth of the car and the sizes of all the pieces.

Just wondering if anyone has any tips on how to perform calculations to determine suitable rotor sizes front to rear regarding: load transfer, tire friction coefficient, deceleration G's, rotor coefficients, clamping force/master cylinder sizes etc etc.....


I have like a month looking some information on internet but its really hard to find some ecuations that helps.

I would be very thankful if somebody could help me to find or already have information about this topics.

best luck for all your teams.

Oswaldo Leon
Team Formula Sae UCV
Caracas, Venezuela
Engineering Excellence

[Cement Legs]

If you do a search for brake calculations on this site there was one post a few months ago that pointed out a system dynamics textbook that was very helpful to us. While I cant remember the name of the book it had everything in it that we needed to develope a spreadsheet that would allow you to change any variable including balance and get the resultant diameters for rotor, caliper cylinder, master cylinder, etc.

[rjwoods77]

We might give you ours if you have some analysis tool to trade. Personal message me.

[kwancho]

It's "Modeling and Simulation of Dynamic Systems" by Robert L. Woods (the UTA Faculty Advisor). I have it sitting in front of me, and the brake calculations look very thorough. Highly recommended.

[Cement Legs]

Yes thats the one.... He goes throught the entire setup process in his textbook and the example he uses is a FSAE car! Cant go wrong.

[milky]

I used The Brake Handbook by Fred Puhn, which is a good starting point. I did the same as you, starting out looking on the net for brake calcs, but there was a huge range in the results that I got. You may well find that with the number of assumptions you make on the way, the values you get, even using a reputable method, need to be taken with certain quantities of salt...

[Kurt Bilinski]

Try this:
http://www.7builder.com/Downloads/MikesBrakes.xls

Note there are four pages to the spreadsheet. What sucks is the values don't carry over between the pages, but it's free...

The last page is the most useful.

[WALDOPIPE]

Thanks a lot kb58. I have two days studying all the information that you gave it to me, there are some things that i dont know what are but im trying to do my best. The problem that our team have is that cause we are in venezuela there are just a few books that helps us out in our problem. Im trying to find the books that some other guys here in the forum told me but they are kind of expensive and our sponsors have not get to us yet.

Thank you again. You have just won a bottle of venezuelan run from a friend here in venezuela.

Oswaldo Leon
TEAM FORMULA SAE UCV
UNIVERSIDAD CENTRAL DE VENEZUELA