Other than Mat who started this thread, Jed, and one or two others I don't believe there are that many ABS units installed. Other than it being a tad noisy I don't recall any negative comments of those that have them. Do believe you are the first to confirm ABS recommends a higher pedal ratio then those installations have had though. That has been one of my main concerns and to the best of my knowledge no one has experimented to see what the system does with no boost.
It has been speculated that fitting a narrow bore master more or less the same size as the original BTV might work but that is a big unknown and until recently no one has tried it. The BTV displacing fluid instead of pushing fluid ahead of the piston introduces different dynamics so until someone tries it without power it may still have the same ratio issues as the larger diameter masters. Here is a post and thread
showing a VW narrow bore master setup. While it appears to work with power, unfortunately it will be awhile before he can try it without power. If it does work, other than the adapter plate the installation looks to be fairly inexpensive and easy with no in depth modifications to the car required.
This Post was from: https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?post_id=164078