Clutch master cylinder

[gtr-gaz]

I changed mine from the 3/4 to 5/8 as some others have done, but I could not get the pedal travel required to work the clutch.

I tried all sorts, including repositioning the pivot bolt to the furthest hole away from the driver.
This inclined the pedal at about 45 degrees meaning the pedal moved about a foot. Still not enough.

I have put the original back on now.

If it worked for all Ultimas, surely the factory would use them??

I would imagine they have experimented wiyh them?

I seem to remember from a build site, someone making a bracket to raise the pivot point on the pedal, thus giving more leverage.
I think it was one of our american friends, but I cant find it anywhere. Any ideas?

Gary

[USCANAM]

Checked my buildsite
http://home.comcast.net/~rosenracing2/wsb/html/view.cgi-photo.html--SiteID-574428.html
and I'm using the center hole with the supplied cylinder from Ultima. Make sure that you've opened up the pedal arm so the pushrod can get full travel.
Using a standard Porsche slave cylinder and a high horsepower Porsche clutch supplied from Power Haus II
http://home.comcast.net/~rosenracing/wsb/html/view.cgi-photo.html--SiteID-571437.html
and I have to say that it is one of the smoothest clutches I've ever had. Granted, a long stint in stop and go traffic will make me aware of the muscles in my left leg, but it is bearable.
Jack

[gdr]

Gary,
The smaller master cylinder worked for me using the middle hole in the floor pivot. Possibly the 5/8" cylinder doesn't give sufficient travel for all clutch configurations which is why the factory use the 3/4". The 3/4" gave too much travel for me causing arm-on-rotating-parts interference. This was main reason I switched, lighter clutch a nice side effect. Are you sure you've got all the air out? It can be a bit tricky.

>> Edited by gdr on Thursday 23 September 20:13

[davefiddes]

I'm using the same setup as George with the 5/8" master cylinder and the pedal in the middle hole. I'm running a G50/03 like George.

Bit concerned with the problem you've been having. What gearbox are you running? Maybe it is a different story with the older pre-1990 G50s? Another possibility is that maybe the slave cylinder is different. I'll have a look on my car tomorrow and post the Porsche part no if I can read it.

[BigAl1]

While not even close to running yet, I have my brake pedal in the middle hole, and using a 0.700" master cylinder from Wilwood - it looks identical and fit perfectly. I purposely went with 0.700" to split the middle, based on earlier posts about clutch stiffness and the improvements from the 5/8" MC install.

Allan

[gtr-gaz]

Thanks for the help.

Jack, that was the pic I was looking for!
I've looked at so much over the last year I can't remember what's where.

I shall mess about with it over winter, which is not to far away now. Right now I just want to drive it!

I,m pretty sure my box is a G50/03 with my starter engine side.

The slave cylinder was supplied by Ultima, so that must be right.

I'm confident I got all the air out of the system. Maybe I'll have another attempt later in the year.

It seems to be getting easier now. Not so much of a pain when stuck in traffic.

Gary

[shithotfast]

The travel needed is for a standard single plate clutch I assume? If you change to a twin plate, or triple plate TITON or similar, the travel you need is around half an inch max. My pedel travel is restricted so as not to have overstroke. Pedel travel is around 2 inchs max. I think this is covered elsewhere on this site. I can give details of the clutch I have if needed... (standard G50 box and ultima plate etc)