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      05-10-2019, 07:53 AM   #217
5mall5nail5
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Drives: E34 525i Turbo
Join Date: Oct 2008
Location: PA

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Quote:
Originally Posted by Waltabeast View Post
Thank for the reply! Yeah i just read through the forum that was shared hontherw. Guess it relates to exactly what you stated and if not done braking can feel “mushy”. Guess I’ll have to learn how to code :/ lol
So I have designed my own BBK previously and am familiar with how master, slave, and caliper piston sizes relate. I couldn't for the life of me understand how a software change could impact the feel of a mechanical hydraulic system.

When I install my M Performance BBK I decided to go around the neighborhood without coding first to see. Yes, the pedal feels like the master cylinder is too small. It took more pedal travel to do the same amount of displacement than stock. This felt typical of a setup where the caliper area is too large for the master and slave match up.

I then coded the car and backed out of the driveway and took the same test drive. Completely back to stock or similar feel. Very bizarre. It's not a bleeding issue or anything as I use a pressure bleeder and flushed the inner/outer bleeders 6x alternating, tapping the calipers, etc. After coding, feeling is amazing. This is paired with Stoptech SS lines.

I can only assume that there is some sort of valve within the ABS/DSC that limits pressure/flow in the braking system. Maybe it's a biasing valve, maybe it's a flow valve, but either way, something absolutely changes in the hydraulic system and it's not the master or slave cylinders.
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