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Interesting. Could you give us the diameter of the VW master piston or the specific application you used and do the brakes function adequately in an emergency without having any vacuum assist -- say if the engine died and reserve ran out does the car still stop. That emergency stop is another of the reasons the pedal ratio has been increased but the modern masters used have all been fairly large diameter.

Cyl I used was a DORMAN M90547 (Rock Auto $19.36USD). As I said in my previous post the diameter is 17mm (0.67").


EDIT
Now, out of habit I give myself a lot of room to stop. My first classic is my 1967 Galaxie with a 390 4V. It has a lot of go but not much stop (originally manual brakes).

Thanks for the Dorman application and apologies for my missing the piston diameter the first time around. How the emergency stop compares to a BTV is still a question though.

There has been some speculation the narrow diameter cylinder would work with the original ratio but as far as I know you are the first to try it. A definitive answer as to how well everything functions under regular and adverse conditions might go a long way toward others adapting your approach.

I havn't had any adverse conditions yet so I couldn't tell you, honestly. It seems to work great so far, if a bit touchy (tap the brakes and put your head thru the windshield sometimes). Biggest reason I went with the VW after some talking to a friend of mine who has about 6 of them from the 60's is that not only the volumetric ration is close but the replacement parts is $20 compared to the rebuild cost of the BTV. It's also a more modern positive displacement design, without that pesky compensation valve that delaminates. I bought my car on 30Mar14 and have maybe 500mi on it since, so only time will tell.

Just adding photos of my setup. I'm not pushing anyone this direction, just putting out ideas.

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That stock look is most definitely what people are looking for in a modern conversion. It might be interesting if you had time to disconnect the vacuum source at the manifold or check valve, plug the port and then tried the brakes just to see how well they work without assist.

I have a lot of work to do on it first (all wheels need adjustment and the left front wheel cyl needs replacing) Maybe if I'm feeling brave I'll try it.

Don- Nice application. Please keep the Forum posted on how it works for multiple applications....and if possible with the vacuum disconnected to address Howard's concern on the 1/1 ratio.
There are many of us who would love to replace the BTV
with something modern. Obviously the dual master cylinder would be a bonus, but having new parts and original pedal location would be a big step in the right direction.
If you elect to be Howard's test pilot please do it on a flat surface at low speed and nothing to afford a sudden stop....like a bus. LOL
Thanks for the post and specifics.
RJR

1.68:1 ratio actually, but yeah I'll keep in touch as far as how this works out. The dual cylinder was 19mm and the length would interfere with the frame in it's stock location, leading to Craig's extensive rework.

BRILLIANT!!!! Absolutely brilliant. Thanks for sharing.

U very well may have just made yourself a place in Packard history.