Master cylider size. Help

[t45_ste]

Evening all

Im after some advice regarding what size master cylinders to use on my nova.

My front brakes are AP racing CP5200 four pots

On the rear im using golf discs and calipers.

Im also using hydraulic clutch release.

Please can somebody tell me what size cylinders i should be using.

Cheers

Ste

[mowgli]

god knows... ring AP for advice is my suggestion

[t45_ste]

Cheers lol

[mowgli]

honestly, i've never seen that brake spec before on a nova. i'm sure a twin cylinder setup is the way to go, but somebody with a shed full of knowledge is who you need

[t45_ste]

Yeah im going to be using twin cylinder for the braking side as im using an AP racing floor mounted pedals. Smae as these

http://www.apracing.com/pics/productpics/cp5500_2.jpg


You never know there may be somebody on here who can help. I think maybe ollie dhdev?

[Mike]

.60 Girling. Maybe lol

As Mow said, id ring AP. Think you may be pishing in the wind asking that kinda qeustion on here lol

[gmd]

i have alcons with 300mm discs and golf rear's. i have .70 front and .625 rear with that setup on my car the pedal box is set in the middle.

[nova1600]

You should always have a bigger master cycliner to the rear to reduce the pressure. You need more pressure to the front to stop the rears locking up first and the front does the majority of the braking anyways.

Most nova rally cars would use .7 or .625 to the front and .75 to the rear. The .7 or .625 for the front would depend on what way you want the pedal to feel. Harry Hockly and the nova competition build guide book recommend the 0.7" cylinder for the front and .75 for the rear

Having it set this way you bias pedal box should only need minor adjustment to the front to get the bias spot on.

If you still find the rear brakes locking up in the back with the bias wound completely to the front you could put an inline reducer on the line to the back. Though I wouldn't expect it with that set up.

.7 on the clutch should be fine.

[t45_ste]

Excellent, thanks everybody for you help :thumb:

[t45_ste]

Would a (.875") 7/8" be suitable for the clutch release?

[nova1600]

Normaly it is .625 that is used. I wouldn't use the 7/8th because even though you will have a lighter pedal (pushing more fluid) you could end up over pushing the the release bearing and end up damaging the thrust washer on the crank for the endfloat. Basically pushing the crank.

[t45_ste]

:thumb: Cheers

[t45_ste]

Which makes the pedal harder on the brakes 0.625 or 0.7?

Sorry for all the questions.

[nova1600]

No bother.
I should really say that its the travel on the pedal that the master cylinder affects. Therefore .625 will mean that you have to push the pedal further to get the same amount of fluid as the .70.