M/C Upgrade

[NYBugman1972]

So, it has come to my attention recently that I need a new Master Cylinder. I figure that I might as well upgrade while I have the chance.

What's a good M/C to upgrade to? I prefer Porsche parts, but am open to anything. I'm not afraid to do some surgery. Any thoughts?

Oh, if it helps any, I will eventually upgrade to disks out back, and probably the Remmele kit up front. Currently, I have the standard disks up front and drums out back.

Thoughts?

[NYBugman1972]

C'mon. 20+ views and NOBODY knows a M/C that'll fit? I know one of you guys know.

[Alex]

There is a M/C that Kerscher sells for their disk kits. It is supposed to be a lot better for that application. Do not know from which car it is. You can ask Oliver in his forum. He sells them.

I think a 944 M/C will be to big and I do not know the size of the old 911 units. You could also use the stock VW one for that application but I do not know how long the pedal travel would be.

Alex

[NYBugman1972]

I will post it up ASAP. I figured the stock M/C would work with the big brakes, but I figured I have the chance to upgrade, so why not?

[Pillow]

Mike Ghia is running a 911 unit and it seems to do really well. This is what I plan to do on mine.

The 944 is really nice as well, but a little longer which may be a problem.

BTW get the ATE units and not the Girling as they mount differently.

Either way I think you are cool. Just get rid of any MC that is drum related when switching to discs.

[chigger]

This is how it was explained to me. Drum brakes and single pot calipers require more fluid to move the pads until they contact the rotor or drum. The larger 21mm 944 unit usually came with a vacuum servo. The reason is that the larger diameter MC has less mechanical advantage. In other words if you use it without the booster the petal is harder to push for a shorter distance to get the same braking response. 2, 4, 6 pot calipers require less fluid movement to achive contact with the rotor so they work best with a smaller MC which has a higher mechanical advantage. Less petal pressure, but more travel to get the same braking force. In some disk drum race cars, they use dual MCs matched to the front and rear systems with an adjustable balance bar to adjust brake bias. I will be using Wilwood 4 pot calipers on all four wheels. Until I identify a problem I am staying with the dual circuit Bug MC. While looking for some thing else, I ran across a 21mm MC for a 944 without the brake booster. It may come on the turbo model as it has four pot calipers all around I think.

[dgluyas]

I have used the standard bug master cylinder with the turbo 944 calipers. The setup works very well. I have found the pedal feels good .Only needs to be depressed about 1.5 inches over stock. You must bleed the brakes properly though!

[NYBugman1972]

Thanks guys. I decided to go with a German stock replacement for now. When I get into the brakes, I'll do more research.