Help me select my master cylinder - Lateral-g Forums

Che70velle · #1 02-22-2014, 03:06 PM

Guys I need to pull the trigger on my master cylinder. I THINK I'm gonna run power brakes, at least that's my plan as I write this, unless you guys talk me out of it. I have wilwood 6 piston calipers on the front, and 4 piston on the rear. My piston area for my front calipers is 5.06". My piston area for my rear calipers is 3.00".
This is gonna be a 95% street cruiser, and will dodge cones only occasionally.
I've had my eyes on the CPP MCPV, for a while, but I don't want to buy the wrong unit. Should I go with a Wilwood master, and prop. valve, and why?
I have the stock pedal assembly, going back in, so no change in motion ratio.
I need help determining bore sizing, and which brand works for you guys. Car is 70 Chevelle, if that matters.
Thanks in advance!

MarkM66 · #2 02-23-2014, 07:17 AM

I would think Wilwood would be able to give you some good advice. Have you asked them?

70 tt rustang · #3 02-23-2014, 02:19 PM

I would consult baer brakes and get a bore size and then contact wilwood

Apogee · #4 02-24-2014, 09:48 AM

If you think you're going to go with power brakes, then we'll need a little more info. First, vacuum or hydroboost? If vacuum, what are your vacuum levels at idle? Generally speaking, a larger booster will supply more gain/boost, and potentially impact MC bore size given the rest of the system. Assuming 14 inches Hg at idle or better, I would probably suggest a dual-8" or dual-9" booster and a 1" to 1-1/16" bore MC for best results.

If hydroboost, I would start with a 1-1/8" bore MC.

As for MC brand, that's up to you and how much you want to spend. I prefer standalone master cylinders without integral proportioning/metering in the outlet ports, as it makes troubleshooting easier and typically cheaper down the road. There's a reason the 1" and 1-1/8" C3 Corvette units are so popular both in their OE form and all of the aftermarket knockoffs.

Tobin
KORE3

Che70velle · #5 02-25-2014, 10:32 PM

It will be vacuum booster. No idea on amount of available vacuum, as I am still building car, and buying lots of parts currently. Engine is a ly6, but has a Mast camshaft, so vacuum at idle is anyone's guess. I haven't started car yet.
I found some formulas on Wilwoods website, and Baers websites, and doing some math, I come up with just a tad under 1 1/8" for my bore sizing, but there are other variables out there, such as those suggested by you guys, that will affect the outcome of this, and that's why I'm asking for help.
Thanks for the replies!