The Cal-look Lounge

Didn't want to dilute Jim's thread...

I thought I remember hearing that a larger Porsche dual circut master will bolt in a VW?? Is there anything better out there than the stock d/c master?

944 355 011 01
944 '84-86 or 924S '87-'88

Maybe a stupid question, but whats the trick with this master cylinder? Will it give more power or a better pedal?

Thanks Jim! Do you use one? It's a bolt in, right? No mods needed?

More on this subject please......  I will be replacing mine soon and any info on this would be awesome.  Details, details........ uh huh.

Anyone? Is it a straight swap? Source for a new one? ???

 ::)

Ask HotrodVW about putting a bigger master in. He put the stock one back in with 4 wheel discs.

Hopefully he'll chime in...

I just did a search on shoptalkforums on this topic. People are using everything from 944, 928, Golf, late Bus... supposedly they all "bolt in", but I just checked out an '86 944 and it doesn't look like a straight swap to me. The thing I like most about it is that they are made of aluminium and are considerably lighter!

I run a late bus master with disc up front and type 3 drums out back.

I also have disc up front and type 3 rear and use a golf master cylinder. Quite a firm pedal and slightly more power.  It is a straight swap, but I think you need a spacer between the cylinder and where it bolts to the 'pan. 

What year Golf(s)?

We bolted a 944 m/c right up to Kafercup's car. Of course he was running 944T calipers.

BTW if you go to larger m/c bore diameter and do not change wheel cyl diameter, you will need to step on brake pedal HARDER to stop car as effectively with original ratio of m/c bore to w/c bore.

[quote author=Zach Gomulka
What year Golf(s)?

not sure on the exact year, but I think it was from a mk2 GTi, with a bore of 20.5mm.  Bugpack do the conversion kit, which is basically a thick ally spacer, longer bolts and a gaiter.  You need to blank off some of the holes for the pipework too, possibly where it used to connect to a servo.  Not sure of its much help, but put some pics on too.


Is this right ???  surely it would make it easier as you need to push the same amount of fluid down the same holes but with a bigger surface area pushing it.  I think it would be easier to stop as effectively but it just makes the pedal feel firmer. But what do I know, I am just a Farmer ;D

Jim is right.  More pedal effort is required if you increase the MC bore.
Let's say you stomp on it with a constant force.  That force gets divided over a bigger area in a larger MC.  This means there's less pressure generated in the pipes.  So less braking happens.  To get the same braking you had with a smaller MC, you need to push harder.
This is why you should always use the smallest MC that works.  Bigger isn't always better.

Furry Muff.  That does sound reasonably sensible.  I was just thinking that if you hit a nail with a bigger hammer.....

Good information here! So I like my pedal effort now, and that is with the stock dual circut 19mm bore master cylinder... So what I'm looking for would be an aluminium master cylinder with the same bore. Priority now is to save weight (this wouldn't be for my GTV, but rather my '67 project. The GTV is fat and happy :))

[/quote]
Jim is right.  More pedal effort is required if you increase the MC bore.
Let's say you stomp on it with a constant force.  That force gets divided over a bigger area in a larger MC.  This means there's less pressure generated in the pipes.  So less braking happens.  To get the same braking you had with a smaller MC, you need to push harder.
This is why you should always use the smallest MC that works.  Bigger isn't always better.
[/quote]

although I suppose with a bigger bore the distance the pedal has to move is less than with a smaller bore.  Good if you have short legs or are just plain lazy :D

yeah the pedal travel "should" be less, if everything else, including pedal geometry, length of bore in m/c, remains the same. (Bigger bore)

My old buddy Wenzel did "something" to his '65 drum equipped Type 1, wish I could remember what it was, but it had better brakes than my 2006 Subaru. They were almost "too" good. You could tip in to the brake pedal and you'd be through the windshield. I know he used "something else" for the master, though it was from a Volkswagen.

I vaguely seem to remember him using Bi-metallic shoes from McKenzies too.

that was me actually... got them from McNulty... he got them from McKenzies. Wenzel was running shoes we found from Speed Warehouse, in Hayward. They looked to have lots of metal flecks in the material. In any case, they didn't fade, even WITH Wenzel driving.  ::)

If you want to lose a few ounces by using an aluminum master cylinder, you'd be better served losing the weight off your own body (we're talking a few grams here?).  Stick with a stock master cylinder and add some decent brakes, ie Type III drums and some front discs.  Why re-invent the wheel??  Like Jim and others have posted, the larger diameter master cylinder makes for a harder to push pedal.  The guy I bought my second sandrail from had a 3/4" Girhling cylinder to operate the hydraulic clutch.  It took two grown men and a boy to push the pedal in.  By simply changing to a 5/8" cylinder, it was a whole different ball game.... just like butter.

                                                           You had two grown men and a boy on the floor in front of where you were sitting?????

     ...... sigh :(  you'll pay >:(

I was wondering who these 2 grown men were.....

Well, let's see.... I can't remember their names at the moment, but the boy wore a cape... ;) ;D

Sarge, do you like gladiator movies?

In the SAND?  :o

I only check in at 12 stone, don't need to lose any more weight off my own body! ;D

In all seriousness, the goal for the '67 that this is planned for needs to come in at 1500lbs, race weight with me in it... and NOT look like a gutwagon. Removing "hidden" weight will be of top priority, and I think an aluminium master fits the bill nicely ;)
I haven't figured out brakes yet, was thinking 356 drums all the way 'round... but they are still drums and they still aren't self adjusting. So I'm trying to figure out a solution that will work with my street wheels and my race wheels that are two different patterns... without using adapters...

Hi Zach, which master did you end up using?

Nothing yet. I still have the original in there as far as I know! And when it needs replacing, I guess I'll just use another stock master. I don't want to sacrifice my brakes, they work VERY well as-is :)