Benifits of an aftermarket master cylinder?

[BADNBLK]

I have intermittently felt my original GM master cylinder by-pass from time to time. Not wanting to let a little surprise turn into problem or accident I am planning on replacing my master cylinder.

If I were to upgrade from my factory master cylinder, now is the time to do it...



Are the benifits worth the additional cost?

I have Baer track plus kit all the way around with their adjustable proportioning valve BTW

[andrewb70]

I would get a new AC Delco MC and call it a day.

Andrew

[BADNBLK]

Andrew is that because there is no benifit of the aftermarket master cylinder, other than visual?? Or just what you would do if it were you?

[Vicinity]

Andrew is that because there is no benifit of the aftermarket master cylinder, other than visual?? Or just what you would do if it were you?

That's pretty much how I see it.

A Wilwood over an AC Delco is just engine bay bling.

That's not to say I wouldn't love to have one.

[parsonsj]

The main benefit is that you can size the master for your needs. If the OEM setup is properly sized then you're golden. Otherwise, aftermarket choices abound.

[andrewb70]

The main benefit is that you can size the master for your needs. If the OEM setup is properly sized then you're golden. Otherwise, aftermarket choices abound.

Exactly. If the OEM MC is the right one for your brakes, then there is no reason to change. If however, you have changed your brake setup and now need a MC with a different bore size than what is in the stock MC, then an aftermarket solution is required.

Andrew

[BADNBLK]

I doubt I really need one, but then again I'm not sure if the upgraded Baer pbr calipers, from stock single piston/drum combo would need a larger bore size?

How do you know when larger bore MC is needed? Is there symtoms of not enough MC?

Thanks guys.

[Vicinity]

I believe it's bigger bore for a harder (less travel) pedal and a smaller bore for a softer (longer travel) pedal.

EDIT: So if you're smashing your pedal to the floor and the brakes are not locking up completely, you need a bigger bore.

[Apogee]

Master cylinder bore size is inversely related to pressure, so the bigger the bore, the less pressure it will provide for a given pedal input force. Volume output is directly related to MC bore size, opposite pressure, so the larger the bore, the greater the volume per inch of pedal travel.

A common misconception is that "big" brake kits have larger caliper piston areas when the opposite is typically true. A factory 3rd-gen (w/o 1LE performance package) came with 2.5" single-piston calipers up front with 4.9 square inches of piston area mounted up on a 10.5" diameter, 1" thick rotor. A C5/C6 Corvette kit has 40.5mm [1.59"] twin-piston calipers with 4.0 square inches of piston area with 12.8" diameter, 1.26" thick rotors. As such, you'll want a smaller bore master cylinder to generate more pressure, not the other way around.

HTH,
Tobin
KORE3

[parsonsj]

I believe it's bigger bore for a harder (less travel) pedal and a smaller bore for a softer (longer travel) pedal.

That's right, but the counter-intuitive part is that a harder pedal is generating less brake pressure. If you can't lock your brakes with sufficient pedal effort, and you aren't reaching (near) the floor, you need a smaller bore. And, of course, you want the front brakes to lock before the back brakes.

[BADNBLK]

Well that is some great info here guys. I guess I never thought of the effect of the bore size on the pedal effort and pressure... my brains do not work in fluid dynamics. I feel like Andrew was probably best in saying just get OE replacement... The Wilwood masters look cool, but I think I will put the savings toward my LS parts pile

Thannks everyone!