Front Breaks

[Lash]

Hi, I'm in charge of front brakes. I need some help getting started. Any good sites or advice / info ? Any help would be greatly appreciated.

Thanks

[Lash]

Hi, I'm in charge of front brakes. I need some help getting started. Any good sites or advice / info ? Any help would be greatly appreciated.

Thanks

[Chase]

here is something for starters read the tech papers from the stop tech and brake tech websites.The websites should be easy to find. Books out on the subject are pretty much out of date except they do give some small amount of information on calculation and understanding of how brake balance works. I am new to brakes this year as well, but I have plenty of help from current team members and or comp programs from previous teams to guide me a little.

[Nate Notta]

Brake design is funny, in that there's actually no science or math behind it. Most often teams just use whatever is donated, then focus on aesthetics, i.e. paint the calipers a nice colour and polish the rotors.

Hope this helps,

Nate

[Brian Smith]

great advice nate...

I didnt think Canadians had a sence of humor. Or were you being serious? http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Alejandro]

The stoptech website that chase mentioned its one of my favorites. The other one is "Tune to win" from Carol Smith.

We designed and builted our calipers and brake rotors.. and master cylinders, yeeah, I know. we are insane!

[Chase]

man i hope he wasn't serious cause that is plain retarded.

[Nate Notta]

I was just 'taking the piss' as they say, since Lash is on my team.


Nate the Brake Master

[jack]

i would definitely create a spread sheet where you can plug everything in. they get tedious, but the math isnt that bad, just do kinematics stuff to get from the force applied by the foot, down to the force and displacement on the master cylinder. then swich to fluid mech, and back to statics, to find the torque on the wheel. everything will fall out from there, including a better understanding of the system http://fsae.com/groupee_common/emoticons/icon_wink.gif. i measured that a good force for lockup (foot pushing on the pedal) is about a hundred pounds, and the hardest a driver can push, is around 450lbs. that should get you started. carrol smiths, tune to win is good. just remember to make the pedal assemblies way stiffer than you think they should be, any defflection makes for a mushy pedal.

[Alastair Clarke]

There's a good chapter on brakes in Paul Van Valkenburgh's book "Race Car Engineering & Mechanics" which goes through a brake sizing calculation in a relatively simple and easy to follow manner.

Other than that, I found the best thing to do was to use Excel as Jack said to answer all the "what if" type questions - i.e. what happens if I use a particular size of caliper, or different master cylinder sizes etc.

One word of warning - don't use motorcycle calipers - they're specifically designed to NOT be able to lock up the rear wheels of a bike - the exact opposite of what we want.

[Kevin Hayward]

Alastair,

There is nothing wrong with using motorcycle calipers. Designing for non-locking of a rear motorcycle wheel is based on system sizing etc nt a fundamental design change in the components.

Another thing you should look at is the temperature of the rotors (front and rear) over a number of brake applications. The friction coefficients of the brake pedal material will change depending on that temperature. As a result your brake balance will change dynamically if there are temperature differentials between the front and rear of the car.

Kev
UWA Motorsport

[RaID]

i got my hand on
Brake Handbook by Fred Puhn

although some info is a bit out of date
it does have a nice design procedure
just to make sure you dont miss anything
as was the case with one of our teams

thats pretty much where i started from along with Tune To Win by C.Smith as mentioned above

[Denny Trimble]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Kevin Hayward:
...The friction coefficients of the brake pedal material will change depending on that temperature. ...
Kev
UWA Motorsport <HR></BLOCKQUOTE>
"I can't keep my damn foot on the brake pedal! It's too slippery!"

Sorry Kev, I couldn't resist...

For our brake calculations, we start with an assumed deceleration (= coefficient of friction of the tires, not exactly true but good enough for my tastes), then get weight transfer, tire normal loads, braking forces (= cf * normal load), brake torques, pad tangent forces, pad normal forces, hydraulic pressure, MC force, bias bar force, and finally foot force. Then we can solve for the bias bar ratio required to achieve that stop on that surface (CF).

[Chase]

Whys my foot so hot?! http://fsae.com/groupee_common/emoticons/icon_mad.gif Man you designed too much friction into this brake pedal. http://fsae.com/groupee_common/emoticons/icon_biggrin.gif

[Kevin Hayward]

Very funny guys

Did I actually write "pedal" ... of course I meant "fluid" http://fsae.com/groupee_common/emoticons/icon_smile.gif

Kev

[RaID]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Kevin Hayward:
Very funny guys

Did I actually write "pedal" ... of course I meant "fluid" http://fsae.com/groupee_common/emoticons/icon_smile.gif

Kev <HR></BLOCKQUOTE>

hmmmmm dont you mean "pad" ?

[Kevin Hayward]

RaID,

Of course I meant pad ... the fluid comment was a failed attempt at sarcasm.

However if the temperature of the fluid changes its viscosity will also alter. This will affect the amount of fluid friction in the lines. Given the rear brake lines are undoubtedly longer than the front this will affect balance ... probably by a poofteenth of bugger all.

Kev

[RaID]

a bit hard to judge sarcasm on forums sometimes

[Kevin Hayward]

RaID,

I'm not too concerned.

My general lack of interpersonal skills and communication ability is one of the reasons I want to play with fast cars http://fsae.com/groupee_common/emoticons/icon_smile.gif

Kev

[Lash]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Alejandro:
The stoptech website that chase mentioned its one of my favorites. The other one is "Tune to win" from Carol Smith.

We designed and builted our calipers and brake rotors.. and master cylinders, yeeah, I know. we are insane! <HR></BLOCKQUOTE>

WellWell, I'm very proud of yah !! P.S. whats Builted?

[Charlie]

I'm guessing Alejandro has english only as a second language.

Judging by the title of your post I hope you do too; you aren't exactly one to talk. http://fsae.com/groupee_common/emoticons/icon_wink.gif

[Lash]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by NateNantais:
Brake design is funny, in that there's actually no science or math behind it. Most often teams just use whatever is donated, then focus on aesthetics, i.e. paint the calipers a nice colour and polish the rotors.

Hope this helps,

Nate <HR></BLOCKQUOTE>

Yeah it Does!! thanks, now all I have to do is build a hammer so I can smack myself over the head with it.

[Denny Trimble]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Charlie:
Judging by the title of your post I hope you [speak english as a second language] too; you aren't exactly one to talk. http://fsae.com/groupee_common/emoticons/icon_wink.gif <HR></BLOCKQUOTE>

I was waiting to say something along those lines... http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Lash]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Brian Smith:
great advice nate...

I didnt think Canadians had a sence of humor. Or were you being serious? http://fsae.com/groupee_common/emoticons/icon_smile.gif <HR></BLOCKQUOTE>

He was serious, Thats all of us Canadians are is serious. We don't have a sense of humor. We also live in Igloo's and eat seals for breakfast. In fact John (from the office) caught a polar bear last night. In fact Whales weren't even born with blow holes.....The Canadians put em there !!