View Single Post
Old 09-02-2020, 06:28 AM   #93
Board Member
Join Date: Jul 2012
Location: Germany

Originally Posted by vintagewrench View Post
For what its worth on disc front, drum rear 120/1800 cars they can be used without a booster. I took it off of my '67 1800s for weight loss, which has a dual master two years ago and have logged 10k road miles and 900+ road racing miles with the VSCCA. At the same time Green Stuff pads were installed and it stops fine, but needs a higher pedal effort.

R32RennSport recently installed Porterfield pads in his 120 w/o a booster on Ian at High Performance Volvo recommendation and also reports good results.

The original master cylinder is 7/8" but the earlier models made before Girling boosters came into use had 1" bore units for higher pressure. I'm going to install a dual 1" Wildwood unit over the off season because I want more braking with less effort on the road. Although on the track the brakes work excellent as is.

I don't know how well this would work on the later all disc brake cars, but it might be worth taking a look at?

If you use a 1" master instead of a 7/8" master and the same power with your foot the pressure in the brake system will be lower.

Pressure: p=F/A

The higher A is, the lower will be p

The volume will be more at same level of pedal.

At same hydraulic pressure the pressure at your sole of your foot will be higher.

If you swap disc brakes to a drum system you need more volume, and pressure.

Modify the linkage at your brake pedal will be the solution

Good luck, Kay
mocambique-amazone is offline   Reply With Quote