vstol

I have always had a vacuum assisted brake system however I think
I'am going with just the Wilwood 1 inch bore manual system. I am converting a 71 corvette into L-88 road racer, custom frame, C4 suspension, LS3/515hp carb with TKO 600. I spoke with Wilwood and they said if I go with the 1 inch bore Master Brake Cylinder and increase the stock brake pedal arm ratio to 6:1 I should get a very firm pedal and no need for a vacuum assist. Any thoughts or comments from the team? Thanks Kevin

flink

Con: When you remove the booster you will make changes to provide additional mechanical advantage: larger pedal ratio, smaller master cyl, larger slave cyls. All of these things cause less piston travel per pedal push and will accentuate the effects of any pad knockback or pad taper induced piston cocking. This effect is pretty large.

Pro: Higher pedal pressure is better for the driver (this one, at least). The right leg is very strong and pressing *hard* is easy to do. This anchors the ball of the foot firmly on the pedal, permitting more confident and accurate heel-toeing, more consistent brake pressure while wagging the heel at the gas pedal and making it easier to modulate brake pedal pressure whilst heel-toeing.

ScaryFast

What is the boost ratio on the car? I know mine was about 4:1, that's a big mechanical advantage to overcome with pedal geometry and MC changes.

Not impossible, but more work than simply pulling the booster off and making an adapter bracket. I opted NOT to pull the booster, and instead am modifying the rest of the system upstream of the "apply" mechanism.

69autoXr

Stock manual brake C3's used a 1" bore MC. There should already be a hole in the pedal arm for the manual setup. I don't remember what the stock pedal ratio is. You will have to mount the MC higher on the firewall relative to the booster C/L to change the pedal ratio.

vstol

Thanks for the comments. Currently I have the old brake system in the car but it will be upgraded just not sure if it will be MC or boosted. A boosted pedal ratio is 4:1. and it will take some work to go MC.