Boosterless setup technical

[Jean]

I am hoping someone who has done some testing on this can add some input. I am removing the stock e30 booster/master setup in favor of Garagistic booster delete kit, as that's the route I chose my for v8 swap.

What I would like to find out is, how do I pick the right pedals and master(s) in order for it to work properly? I am using late model 325i front/rear calipers/rotors, car does not/will not have abs system. It is rarely driven on the street, and it's whole purpose is to compete in scca autocross.

What should I look for specifically in the pedals and master to make sure it's "Sized" correctly?

Info on the kit here -

http://store.garagistic.com/ocart/e30%20boosterless%20brake%20setup

[!kid]

some info hear that should help you out.

http://www.e30tech.com/forum/showthread.php?t=103984

[Massive Lee]

Hey Jean.

I am glad somebody's offering an install kit for a twin MC pedal box. Did you ask the Garagistic guys about the MC sizing?

Lee

[garagistic]

Lee, if you would like to chime in feel free, we know that your experience in brakes on e30 cars is vast. Any knowledge with these cars helps everyone.


Although there are a few factors, matching bore size depends on brake setup and primary use. Will the car be used on streets (meaning less pedal effort and less fatigue)? Track only (need a firmer pedal/performance)? Little bit of both (something in between)?

We usually recommend 5/8 bore all the way around to start. This is the safe bet to make sure the pedal is not so unbearable when you apply the brakes. It is the bore that will allow least effort to be applied. However the "throw" of the pedal will be longer. If the car will be used on the streets quite a bit, this may be the best bet simply because of the effort needed to push the pedal over and over and over again in normal street driving.

Bigger bores mean less throw, produces more volume, and a firmer pedal.

Smaller bores mean more throw, produces more pressure, and a softer pedal.

Some customers who daily their cars with this boosterless setup use 5/8 all around and this is what we tested with.

However other customers who track the car (or have the e36 m front and 318 rear) can compensate by using 3/4 front and 5/8 back to compensate for the bore diffrences.

As always, the balance bar can supply the fine tuning to get the biased just right.

It will take some experimenting but 5/8 is a good/safe place to start. If you desire a firmer pedal step up to the next bore.

General rule of thumbs:

Bigger bores: Minimal pedal travel/stiffer pedal/higher pedal effort.

Smaller bores: Long pedal travel/softer pedal/less pedal effort. All grade 8 hardware included.

If you increase the diameter of the master cylinder you will reduce line pressure which reduces clamping force.


Lee if I missed anything please feel free.

[Vtec?lol]

it all depends on comfort and caliper size
you'll need the compact master cylinders. Pretty much goes in order from 5/8 being the softest with most pedal travel to 1" being the stiffest and least pedal travel.
I think the pedals are 6.25:1 and 6:1

[Massive Lee]

@ garagistic- The rules of thumb were very clearly laid out. Good job. Start small. On a stock caliper, start at 5/8", remove the fixed bias valve and see how it feels at the track. Brake hard in straight line and check what locks first. Adjust balance bar, or swap MCs. People will usually buy two or three extra MCs to test out.

[Jean]

Awesome, thanks for input! Now to order a pedal box and masters next.