After eight long years, I finally got my Charger on the road and slowly working out the little bugs but I have one that I need a little help on.

I converted the brakes from the stock 10" drum to 11" drum on the rear and I used a Wilwood kit disk conversion kit (140-2721-B) for the front. Thinking I may not have decent vacuum for power brakes and seeing that the brakes were being upgraded, I also converted over to standard brakes. I used the original brake pedal with no modifications and the master cylinder is one of Rick Ehrenberg's aluminum units with the 1 1/32" bore. I decided on this master beasue I thought I may need the additional volume for the four piston Wilwood calipers and was hoping that the pedal effort would not be too objectionable.

The problem is the pedal effort required is alot more than I would like. I thought about changing the pedal ratio, but I don't think I have enough room to compensate for the additional pedal movement required. I could change the shape of the pedal arm to raise it a bit, but I think that may raise the pedal too high and make it uncomfortable. I could also change the master cylinder to another with a smaller bore but again, I'm concerned about the total pedal movement.

Another thought was to install a hydroboost to go back to a power brake setup without the vacuum pot. The car has power steering so the hydraulics part is in place (assuming the power steering pump can handle both steering and brakes). I also thought about changing the rear drums over to a disk setup as well.

Anyone out there done a similar conversion? If so, what was your experience with pedal effort and did you simply live with it or what did you do to fix the issue?

Thanks

I think you need to use the manual brake petal and not the the power one.
What are use using for a proportioning valve?
Not sure off the top of my head if your MC bore is right?
Don't throw money at by going disc in the back, I don't think that will fix it.

I have power brakes on both my cars with some good sized cams. Just have run enough timing is all.

Good luck with your Wilwoods.

some of the old chysler iron had 2 different holes in the pedal arm and a way to drop the master on the firewall so it was in a straight line--you must be to new----bob

Ehrenberg usually sells 1 1/8" bore master cylinders. This master cylinder may result in a hard pedal and low line pressure when used with the small bore Wilwood calipers.

Measure/post what pedal ratio you have. R U comfortable w the pedal height?

It has the Wilwood proportioning valve right now. Tried adjusting it but didn't change much.

I thought I'd measured it but I do have another master cylinder here so maybe it is the one I'm thinking has the 1 1/32 bore. Maybe I'll try swapping that one in first before anything else. Any recommendation as to the bore size I should use?

The pedal is the original power brake pedal but I haven't measured the ratio. Pedal height now is right where I think it should be and is comfortable but I'm not sure if I would have enough travel if I change the pedal ratio. Any idea what the normal power brake and manual brake ratios would be?

W more thought I think I'm off kilter on that (pedal ratio) as I'm sure when the PB assy was changed out & a regular pushrod added that if the hole located it way off from horizontle you would have noticed it but that is the small dimention in the ratio formula so maybe a fraction of an inch ch there WILL make a big diff & it never hurts to have all the facts at your disposal but prob k.i.s.s. that unless the friction material (CF) is not agressive enough, that the MC bore is too big making the effort 2 high esp if it stops well w alot of foot pressure but on my 65 dart (74 discs/10" drums) OE drum splitter 1&1/8" mc it stops perfect which it is a mismatched setup but there's no excessive pad/rotor wear (semi met) or excessive pedal effort & only locks up the rear on a panic stop & putting around town it's never a prob

You should confirm the 1 1/32" MC bore size, first.

You were right, Cass. The master cylinder was 1 1/8". Since I already had it off to check the size I figured I might as well install the 1 1/32" one I had to try and the pedal effort is much better now. Is it worthwhile looking at the 15/16" bore size to reduce that effort even more or is that going to affect the volume required too much?

Thanks

The 15/16" bore master will work with your system, but it will yield a longer, lighter pedal stroke. It will definitely increse the line pressure at the pads, however.

If you are interested, I just finished building a bunch of new, aluminum 15/16" bore masters. I also stock the 1 1/32" units.