Hey guys, i have a 3line master cylinder.
Rear , Front, Front.

The problem is that im having alot of problems with the 3 line cylinders. They stop working too easily.

My question is:

Is it possible to use a 2 line master cylinder, and then split the front output just as the back splits?

I searched, but i think i may be searching the wrong thing or no one tries something like this? Im not sure, but any information will be much appriciated. If there are any forums that you guys can link me too.

hey, just wondering if anyone can help with this?

Ok leme ask a question. What is the master cylinder ratio of front to rear on a Nissan Non ABS cylinder? if i were to get a 2:1 ratio cylinder, will this properly stop my ride? or is it not the proper ratios?

Hydraulically they should be the same. I ran one on a track car and didn't notice any difference.

Well i did some more digging, and it turns out that the front to rear ratio of the CALIPERS for the R33 GTS-T is 2.239. That means the TOTAL area of the front pistons is more than 2x that of the rear. ( 8 pistons infront, 4 in the rear ). So with this information, if i were to buy an aftermarket brake Master cylinder of size, 1 1/8inch, with a front to rear ratio of 2:1, then use a proportioning valve to avoid rear lockup, then i would have myself a system i can configure with more rear brake bias than stock to use the larger than front tires i have on the car.

Does this make any sense? Or am i just thinking about something that just isnt going to work?

I'm curious as to where you're getting the information on pressure ratios. I've just never seen it before. There's a lot more to designing a braking system than just the piston sizes front to rear.

As far as the "not working" of the 3 port masters, what happens? Are you melting seals due to heat from turbos or something like that? Anything wrong with the cylinders you have as far as braking goes before they stop working?

Are you fixed to keeping stockish parts on the car? You could always go to something with individual front and rear cylinders and adjustable bias.

http://www.jdmlegion.com/KnowledgeBase/ ... b9366bcaf1

that would be where i got that information. i did alot more digging and this same set of information keeps popping up all over so i suspect its either believeable crap or genuine stuff. however, having the gtst r33 rotors and calipers myself, i believe the r33 specs.

the master cylinder that is there for the r33 is a 15/16 master. However i have a 7/8 master. which means my master is too small... difficult part is getting a bigger master...

Now i changed my 7/8 rubbers&seals recently in my master cylinder and i changed ALL the fluid at the same time and bled the system. What i felt immediately was increase "crispness" in the reaction of the braking system. However, what i did not feel was a better pedal feel. The pedal still pretty much goes flat to the floor. Ofcourse the car stops like a thief but that confidence of pedal feel still isnt there. Also, what i noticed is when the rotors are pretty cold (late at night,) the pads almost dont hold, but when it heats up, holy hell it bites!

So im concluding that nothing is wrong with the system, there is no air in the system, the master seals are good, the fluid is right and, i definately need a bigger master for a better feel.

Im also wondering if i should experiement with bigger master cylinders or an aftermarket one just to see how it works and to put it up here for others to see what options are there...

Well if i cant find a bigger nissan cylinder locally, i'll probably just have to do that!

Thanks for all the help guys, if i do get projecty with my brake system, I WILL KEEP you guys updated!

Ok, I took a look at that. The ratios it lists are the physical area of the front pistons vs the rear pistons. I was thinking that you had something that had the actual pressure ratios that the masters put out.

After reading your issues with the system, I think that most of the feel would be fixed with the larger master cylinder. I think that Z32's had the larger one? The cold brakes not biting well sounds like you have a pretty racey pad in there for street use, what pad do you have in there? Also check your rotors for any run out. It can push the pistons back into the caliper and make the initial press on the pedal take a lot of travel. Are you running stainless lines on your brakes?

Sounds like there's not really a lot "wrong" with what you have, just that you could use some tweaks to make it perform better for you.

Yes the ratios are for physical area of the pistons, but there is also a few sites i saw something about a "reduction ratio" of 0.4 thats where i got the idea it might be 2-1 with the front to back volume but 50/50 with the pressure ratio until a certain amount then a "proportioning valve" built into it for the reduction ratio...

I guess im not expert at brakes, and it is a science in itself, but i tried making sense out of non-sense and thats what i came up with.

My lines arent stainless steel, but they are new lines... so i dont see that causing i big difference now.

What is "run out" on the rotors? i dont understand that. Do you mean "grooves"? if that is what u mean, then yes, the rear rotors do have grooves in them. Think that will make a big enough difference on pedal movement? If you do, i think i will take them out and check that out for sure!

Thanks for all your help so far. u've been great.

oh. rotor run out seems to be warping off axis... yes i see why that will make a difference. But wouldnt that also cause vibration when brakes are applied? because i am getting no vibration from my brake system ATALL. there is grooves in the rotor but no warping...

What most people call warping is not really warping at all, rather it's more of an area of the rotor that is higher in pad material deposits than others. Runout would be what you think of as warping traditionally. It's really not something that you would feel as pedal feedback, but it creates a gap between the pads and rotor that needs to be taken up in pedal travel before the brakes start working. Usually not too much of an issue, but I have had a customer that was constantly complaining about brakes to the point that we were always measuring runout on new rotors once they were installed and even made him a set of -2an lines instead of -3 to improve pedal feel.

It's just a place to look to to improve performance because it really doesn't sound like there is much wrong with what you have past pedal feel and travel.