rear Brake project

Post Mon Jul 25, 2011 10:53 pm

just a couple of pics of what iv come up with for cheap as chips, but currently untested so bare with me on the follow up test results.

they are porsche cayenne rear calipers with E46 330d 328mm vented discs

im just designing the fronts now so ill pop a update on them soon too.

Post Wed Jul 27, 2011 8:27 pm

interesting... what are you doing for a MC and bias ?

Post Wed Jul 27, 2011 10:48 pm

well i am going for a new pedal box with a MC for front and a MC for the rear which can be remotely used as a bias. bit of a trial and error jobbie.
pedal will need abit more of a push but i can live with that

Post Wed Jul 27, 2011 10:53 pm

Driftben wrote: pedal will need abit more of a push but i can live with that

not if you get the pedal ratio and the MC sizing correct

Post Wed Jul 27, 2011 10:56 pm

well then thats where the zone (full of great info) comes into play

Post Wed Jul 27, 2011 10:59 pm

Handbrake?

Post Wed Jul 27, 2011 11:02 pm

uses its own MC so will be hydralic, not MOT worthy but track worthy

Post Wed Jul 27, 2011 11:53 pm

What pedal box are you going for out of interest?

Post Thu Jul 28, 2011 7:50 am

the pedal box id be going for will look something like this

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... K:MEWAX:IT

its should be just right

Post Thu Jul 28, 2011 11:05 am

Are you SURE you want floor mounted Ben? Comfortable in a single seater where your bum is flat on the floor and legs near enough outstretched, but not ideal in an E30.

Oodles and oodles and oodles written on here about pedal boxes and sizing your M/C's correctly to get your bias correct. Bias bar won't correct all sins if you get your M/C's the wrong size so you'll need a calculator, pencil and back of a fag packet at some point. Your calliper piston dimensions and disc sizes will feature in these calculations.

Do a search with me as author and "M/C" and "bias" as search strings and volumes should pop up. I modelled both my own and Theo's brake setup using MATLAB, some of these graphs should pop up too. Note the significance of using a brake proportioning valve (like Rix313 has) in addition to the bias bar. Note how the bias bar adjusts static bias while the prop valve adjusts dynamic bias. All important stuff on a track car.

Post Thu Jul 28, 2011 11:14 am

Think you'll find this to be a really useful thread as far as pedal boxes and brakes are concerned.

http://www.e30zone.net/modules.php?name ... c&t=138040

Great looking rear brakes BTW.

Post Thu Jul 28, 2011 1:19 pm

thats one heck of a project you have there geoff, huge thumbs up for that one.
i think you have hit the nail on the head with the pedal box.
what do you think of this pedal box?

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... K:MEWAX:IT

i havent read all the MC thread yet to find out on MC sizes. still need to work that out

Post Thu Jul 28, 2011 3:58 pm

Driftben wrote:thats one heck of a project you have there geoff, huge thumbs up for that one.
i think you have hit the nail on the head with the pedal box.
what do you think of this pedal box?

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... K:MEWAX:IT

i havent read all the MC thread yet to find out on MC sizes. still need to work that out

Ta, thanks Ben.

Those pedals look better, but obviously I have no clue as to the quality. My own pedals are by Tilton, and similar units are available from Wilwood. You'll pay for the well known brands though, but you can trust them.

I’d honestly suggest that you read through all the pedal box threads on here. I had an easy ride with my pedals since I had no exhaust manifold on the other side of the firewall to worry about. Theo was a similar case, but there are plenty of other examples out there of twin M/C’s mounted over the pedals (cylinders inside the cockpit) and twin M/C’s mounted on the left connected by the brake bar. Martin Pallot did quite a bit of work building his own pedal box on the right iirc.

If you do mount your M/C’s on the drivers side facing towards you just be sure that you don’t get a shin full of M/C in the event of an accident. You’ll also need to mount the fluid bottles where you can top them up without getting a mouthful of floor each time. Personally, I actually like the idea of the twin M/C’s mounted internally on the left. But beware the dual M/C Compbrake kit that bolts in place of the servo. This seems to have something of a failed reputation.

These two threads by Motorhole will likely be of some help to you:

http://www.e30zone.net/modules.php?name ... c&t=196955

and

http://www.e30zone.net/modules.php?name ... c&t=197857

Note the brake bias document that I indicate you can download in the first thread. That should help you with your calculations. If my ftp server doesn’t want to let you in I suggest coming back later. It can be cranky some days. There’s a handy excel spreadsheet somewhere in there too.