Has anyone upgraded to a larger brake MC?

[Cacatfish]

Im looking to puch more volume through my master cylinder than my 525i stocker can suffice. Any ideas or experiences?
Thanks, Colin

[632 Regal]

your master cylinder you would have to get one with a larger piston. This will firm up the peddle, give you less travel and significantly deteriorate your braking ability because you have lowered the fluid working pressure.

If you wanted less volume you would need one with a smaller piston which would give you a softer peddle, more travel and significantly MORE braking ability because you have raised the working pressure.

[Cacatfish]

Jeff, thanks for the reply. The reason I want to is that I now have larger 4 piston calipers and the stock MC does not push enough fluid = too much travel for my likes. I remember seeing somewhere on the web, a site that has all the piston diameters of the various BMW MCs, but for the life of Brian, I cant find it. Any ideas of which are the largest? (ie 540, 850, M5, etc).
Thanks, Colin

[632 Regal]

Ill peek around and see if I find anything before you do.

[Brandon J]

I have heard people using e32 750i master cylinders for that reason.

[Cacatfish]

Anyone know piston diameter for e34? Thanks for the note Brandon, I just browsed a little info on that also. Says that the piston diameter for the E32 is 25mm vs 23.8 for the e28. Is the E34 also 23.8? Is there one even larger?
(I dont mind having to push a lilttle harder).
Colin





I have heard people using e32 750i master cylinders for that reason.

[Martin in Bellevue]

Anyone know piston diameter for e34? Thanks for the note Brandon, I just browsed a little info on that also. Says that the piston diameter for the E32 is 25mm vs 23.8 for the e28. Is the E34 also 23.8? Is there one even larger?
(I dont mind having to push a lilttle harder).
Colin

bolt up to the e34's. Check fitments closely.

[Cacatfish]

How about E38 7er or E31 840/850?
Colin

[Paul in NZ]

but why dont you get the mc from the same kinda car that the calipers came off?

[Cacatfish]

It is an aftermarket kit. Not from an oem application.