M K

iTrader: (9)

wanted to get rid of my original master cylinder and servo from my xr2

1 for more room in the bay the other for the fact using anti lag fails your brakes due to the servo/vacuum set up

i cannot adjust them via the balance bar as theres no room between the pedals but have an in car willwood adjuster to put in line of the rears to stop them locking up,,,

the master cylinder push rods are connected via a bar through the pedal so the force applied to them is as good as your gonna get,

i know the pedal will be rock hard etc but do you think this will work ok or be shite and a waste of time???

2 seperate master cylinders - 1 rear / 1 front mounted directly to bulk head on custom alloy plate,,,,,with bar slotted through standard brake pedal attatching to master cylinder push rods,,,

heres the pics



the inside has a plate the same as the engine side but a bit larger to spread out the stress on the bulk head / bolts when heavy braking but have no pics of this as yet




cannot test it yet as engine etc is not ready for a while yet

cheers
marc

Red16

looks good to me be nice to hear what other people who have this kind of setup have to say about it.

i think it'd be good to have a plate on the inside of the bulkhead to spread the load when you stamp on the pedal over a larger area than the 4 bolt heads it has now

ian sibbert

Have you put a tube into the pedal to allow the bias bar to adjust?

I personaly dont like any sort of pressure reducing valve in the rear lines....much better to match the rear cylinder and have front bias...

Martin-Hadland

iTrader: (2)

why not simply mod the pedal to take the proper bias adjuster?

you will definitely need to strengthen the inside of the bulkhead and if you should have a bush either side of the pedal to stop the bar wearing it away.

I would spend a bit more time on it and make it safe.

M K

iTrader: (9)

there s not enough room betwee the accelerator & clutch pedal to allow any adjustment when fitted as the bar fouls the clutch pedal


if that makes sense

martin-reyland - i will be placing a bush either side of the pedal as you suggest to stop play & wear on the bar and pedal

any other ideas to point out to me any1 ????

cheers for all the info
marc

ian sibbert

Have you used a full kit as in the pic below? cos it looks to me like there is no tube on the pedal.....

richm

I'm thinking the same thing... the pedal normally applies pressure to the bar via the spherical bearing mounted inside a tube - this allows two things, lets the pivot point move along the bar as the bearing position is adjusted ( to give bias shift) along the bar, and allows the bar to pivot to allow different piston travel on the two master cylinders (the travel of each cylinder is very likely to be different, so you need to accomodate some angular movement of the bar to allow this)

From my own experience it seems to me that the bar is much too far from the pedal pivot, and you will lose a lot of mechanical advantage (pedal-to-cylinder pressure ratio) and hence effective master cylinder pressure. You will need to apply a LOT of pedal pressure with it mounted where it is, especially if you have no servo's.

richm

surely this means you will get no benefit from the balance bar and twin cylinders, as the bias point will be fixed..??

Micky The Finn

is this real or a joke?

M K

iTrader: (9)

back to the drawing board then

Moose 130

I was told 'a man who never makes mistakes never makes anything'

Don't worry, just try again.

Put it down to constructive critisism.

M K

iTrader: (9)

exactly my point of putting the post up in the 1st place fella,,,,

im NO expert & dont even have a garage with electrics/power to work in but i thought id give it a go

& then find out whats got to be changed

and thats what ive been told now so objective complete

cheers
marc

markk

iTrader: (2)

as above , needs to be alot closer to the pedal pivit to get any mech advantage, you need approx 6:1 ratio to make any real feel to the brakes from the pedal

ian sibbert

Matey,

The installation looks ok to start with...a little low on the bulk/pedal....but to achieve the full installation of a bias set-up you will need to do a bit of welding...your pedal and hole alignments look ok but as Martin says you will need to weld in a strengthening plate to cover the original hole and prevent the bulhead flexing....i was asking about the tube as without this being welded to the pedal you wont acheive an offset pivot (the key to the bias setup)...and as Rich says without this offset pivot you will never acheive more front braking force than rear...once you have sorted these few problems out and got your pieces welded in the bias should work nicely without the need for a pressure reducing valve in the rear line....

The 2 master cylinders should be different sizes..in general front should have .625....rear should be .70



HTH

Ian

CosRush

Here's a pic of mine when i built it if its any help.

NUTS RuS

iTrader: (35)

No use to you (other than for info/ideas) but our direct fit Subaru Impreza ones looked like this in the development stage.



Maybe worth a second thought/re-think - but fair play for having a shot yourself

M K

iTrader: (9)

CHEERS MATE,,,,,

got a few days off now so gonna have a play around,,,

just cant see how to get the pivot point any better as i cant possibly mount the cylinders higher than they are now cos thats were the pedals fix to

richm

Can you reverse the cylinders so they are mounted off a frame welded to the pedal box inside the car, and weld the rod mounting tube to the top of the pedal above the pivot?

This is the common arrangement on MK1/MK2 Escort...

frog

mark, sounds like you've had loads of good advice already, my first thought, was "big hole in the brake pedal = weak point", not something you want to snap in half when you need to give it a biiiiiiig push.

Good luck with attempt no 2.

M K

iTrader: (9)

no mate

not using the original pedal set up

am gonna weld the balance bar tube into the pedal so its nice and strong and allows front/rear bias,,,

but the pivot point will have to stay were it is,,,,will it be that bad in this position??? i know people say 6:5:1 or someting is ideal but i cant mount them higher

CosRush

Why not try and get the proper parts like this
http://www.motorsportengineering.co....ccessories.htm
shouldn't cost too much.

and then get the collar welded onto the pedal similar to the subaru one above.

CosRush

or here
http://www.rallydesign.co.uk/catalog...th=562_580_606

markk

iTrader: (2)

it really is very bad if the pedal ratio isnt high enough pal, i know - ive done it , i made my own bias as well, its cool now but - needs to be really close to the pedal pivot

CosRush

You'll notice if you look at my bias setup above that the pivot is almost right next to the front cylinder (righthand in picture).

having to have an SVA the brake Bias is checked to ensure it is correct (and it was ), but you can see how much bias is forward.

Although i have different size cylinders as well.