How’s your week going?

Hope y’all having a good one. I start a new job on Monday.

Over the weekend I did some well needed maintenance on the daily. Some of the Runners came by to keep me company and throw back some beers.

Wrenching and bullshitting. Even talked about plans for this spring and summer: go fishing more! And from garage talk I relayed some info I found out through some research that’s hard to find even on Honda-Tech about which Brake Master Cylinders come on which cars when it comes to EG chassis’s as well as their proportional valve.

Note: do not use this blog post as a definitive guide for BMC’s and prop valves. I am simply stating my findings. These findings apply to the EG chassis.

The Findings:

The EG6 SiR comes with a 15/16 BMC. All other EG’s model comes with the 13/16 BMC like my VX seen here:

The only Civic in the USA that came with a 15/16 BMC is the EF EX sedan and Si. A lot of people swap over the 15/16 from the EF to their EG to have more brake pressure. The folks who upgraded to a rear disk on their EG’s opt for this swap as well, while others leave the 13/16 BMC on; it works. Especially if they can’t source the 1″ ITR BMC. From a source who has access to EG6 SiR’s and other model EG’s in their country (i.e., VTi) he stated that the EG’s that have the 15/16 BMC’s have a 30/40 proportional valve. Only the top model EG2 came with a 40/40 proportional valve along with some EK’s. So there you have it. Vital information.

My set up is DC2 GSR rear discs, 13/16 BMC (Stock USA EG BMC) with a 30/40 prop valve. I used to run a 40/40 with no problems, but it started leaking so I replaced it with a new 30/40. I felt no difference when I did go from 30/40 to 40/40 and back to 30/40. So in conclusion if you have a set up like mine, the 15/16 BMC it’s ok to use with a 30/40 proportional valve.

Theory:

There are other factors that come into play such as if you upgrade to bigger front discs/calipers etc., that you will have to research. Especially the 1″ BMC. Many would match it with a 40/40 proportional valve. I have no experience with that set up, perhaps you can still use the 30/40 if you only upgraded the rear to a DC2 rear calipers/disc setup and leave the fronts stock on a EG chassis. The difference from the 1″ to 15/16 is a 1/16 difference, so I don’t know if there will be any slop or gain. But if the 15/16 already increases pressure, I would assume the 1″ will also increase pressure as well. Non-ITR DC2 non abs has a 40/40 prop valve with a 15/16 BMC. If you upgrade the front calipers on the EG to a DC caliper, you need to match it with a 40/40 prop valve because the calipers are bigger.

Final Thoughts:

If myself and my source is wrong or if someone would like to add any other info please chime in because I would like to know as well, I am always a student. Many people have felt a significant difference when adding the 15/16 BMC to their EG. Since the 15/16 BMC & 30/40 prop valve come in that set up on the EG6 SiR, you know it works. Once you start upgrading to bigger discs and calipers, that’s when research comes in. I.e., 40/40 prop valve, ITR 1″ BMC.

Thank you to my buddy in France who sent me this BMC, you know who you are 😊 I plan to install the 15/16 BMC onto my EG some time this year, probably once the weather warms up.

Merci.