View Full Version : Brake gurus need help!!

11-19-2005, 08:02 PM
Is there any advantages to moving from the stock 7/8 bore size MC to A 1 inch size master cylinder? this is going to be with stock brake calipers and rotor size, wasnt planning on upgrading this yet but the old one is leaking. I do plan on upgrading to the brembo cross drilled and slotted rotors with SS lines? this will be mainly a daily driver but do plan on going to the track and want something that will be competitive, on the stock rotor sizes. And yes I did search everything I found was on the z32 swap. thanks in advance.

11-19-2005, 11:59 PM
Increasing MC bore size will only flow more fluid per pedal increment. Given that almost all rubber or stretch type lines are upgraded to ss braided, the feel will be totally different. For example, moving from a 7/8 to a 1 1/16. The 7/8 would need to be pressed X amount to begin brake engagement, but it will need to be pressed down a little more to brake harder X+Y. A larger bore unit, like the 1 1/16 will reach the braking engagement point sooner (X), but instead of pressing the pedal further down, it moves enough fluid to almost stay still when trying to press it down harder. So instead of X+Y worth of pedal movement, you only have to move it X amount. With a larger MC, to increase or decrease braking power, you just control those leg muscles instead of actually moving the pedal down further and further (which takes more time). A larger MC makes the braking feel more like a road course race type car rather then luxury street cars. Moving to a 1", which is right in the middle, will give a better balance between engagement and "softness" of the pedal. I personally like the 1 1/16, no matter how hard I press the pedal, its still in the same spot. The harder I press, the harder it brakes. I have never used my 1 1/16 unit with stock calipers though. With a 1" on stock calipers, I would guess it would have the same effect but with a little bit of "smush" in the pedal, but nothing as soft as the 7/8.

11-21-2005, 12:18 PM
If you like the pedal travel in your car now and how much force you need to put into the pedal to stop, then don't change the MC size. If you're looking to decrease your pedal travel by 30% and increase the amout of force you will need to push on the pedal by 30%, then make the change to 1".

Changing out your rotors (of the same diameter) won't make any difference in the way the pedal feels, and changing out the lines will make small differences you may or may not even feel.