jonfoc

I've fitted a pedal box to the focus. My trouble is I've no idea what size master cylinders to use. My brakes are all Alcon with 4 pistons on the front and 2 on the rear. Then there's the clutch, I'm using the standard slave cylinder. On the Ford pedals the cylinder says 19.05.
Any help would be greatly appreciated
Jon

Caddyshack

I believe this is quite a science as it also has calcs due to pedal throw and leverage. Alcon may be able to advise you where to start but it might be a bit trial and error.

The rear on my old bias pedal box has a different size to the front. Do you have any yet? I have 2 on my pedal box that you can try if you want? Mine is a comp brake setup and worked ok on my Cossie brakes.

jonfoc

Once again Toby to the rescue. Cheers mate. I've not bought any yet. I would presume the rear is smaller than the front as the pistons are smaller etc.

Caddyshack

I will look at the sizes that I have, I think they are decent Tipton units. You can then fine tune from there.

jonfoc

Leg.........end!!!!!!

james kiely

iTrader: (5)

might be worth giving martin hadland a shout jon

jonfoc

Good call James

jonfoc

Martin has replied in seconds.

james kiely

iTrader: (5)

martin is the brake guru jon

topman

jonfoc

Toby I've been advised to go with .625 and .7. If you've got these sizes I can try that would be great. It'll save me a few quid if I need to go up or down

Caddyshack

Pretty sure they are the exact ones. Text me on Saturday / sunday if I forget to let you know tomoz

markk

iTrader: (2)

I've been dealing with bias boxes for over 20yrs.
Two pieces of advice.
1) make sure your pedal box is higher than 5:1 ratio.
2) Use either AP racing, Brembo or Alcon cylinders. All others are inferior and will reduce brake efficiency and not last.

Caddyshack

I am sending Jon my AP ones to try.

jonfoc

Thanks Mark great input and advise. Toby to the rescue with AP cylinders.

@Mark how do you workout the ratio?

markk

iTrader: (2)

Distance from the pivot pin to the end of the pedal versus the pivot pin to the cylinder/clevis connection to the pedal, these are the ratio :1.


If the pedal was 200mm long (piviot to pedal end) then the distance from pivot to clevis was 100mm then you would have a 2:1 ratio. (Almost impossible to stop the car lol)

Pivot to clevis at 50mm would be 4:1.

You got it?

This what I have in mine - brakes are really responsive, no more effort than in a servo assisted car.
http://www.wilwood.com/Pedals/PedalP...emno=340-15074

FLAT TRACK

hi jon
the higher the ratio the more pedal travel you have as well take that into
account
mark