Eta Non ABS master and BBK?

[einstein57]

So i have an 87 325is and the IE 310mm 6 Piston BBK. The ABS has never worked on my car and the pedal has always been a little on the squishy/sinky side. I've driven cars with ABS delete and the pedal feels much better. I don't want to bother with bending new lines and such or running adapters so i was considering going to the yard and pulling the hardlines from an early eta and buying a brand new non-ABS master cylinder. I plan on upgradding my rear brakes to a 4 piston kit within the next year. Will the eta master be up to the task? I don't mind a bit of travel since it will allow better modulation.

[einstein57]

Bueler?

[jlevie]

ABS or not has nothing to do with pedal feel. But in this case the size of the master cylinder w/respect to the brakes does mater. You need a larger master cylinder given the increased volume/area of the BBK.

[einstein57]

So going through the maze inside the ABS pump has zero damping effect? I know on motorcycles you can fell the difference between a cross over feed line to the right caliper vs dual lines from the master cylinder.

[jlevie]

So going through the maze inside the ABS pump has zero damping effect? I know on motorcycles you can fell the difference between a cross over feed line to the right caliper vs dual lines from the master cylinder.

The ABS unit has no damping affect.

[I8UR911]

jlevie is correct. You need a larger master. These masters can BARELY handle a 4 pot BBK let alone a 6 pot.

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[einstein57]

The stock ABS master seems to handle the 6 piston kit fine. A little extra pedal travel but nothiing to write home about. I remember reading that the cylinder for the rear was smaller in the non abs master. This seems like an interesting option.

I have deleted the ABS in two of my e30s. The first time I used a T and
the second time the third port.

Using the third port:

(I need to take better pictures of this setup...)

Using a T


Both method work well. Using a T is a little more work as you need 1
more line and a T. Also it is a bit more work if you want to do a neat job.
If you don't have experience bending lines, be prepared for a little
frustration at first but be patient and the outcome will be worth it.

[wazzu70]

Wheter or not the ABS has an impact on pedal feel depends on how the ABS system itself operates. On the E30 the ABS does not impact the pedal feel either way. The E36 however has major issues if just the abs is installed both on pedal feel and F/R proportion as the system was designed to balance it out. With the ABS removed from an E36 the brakes are overboosted.

Just an FYI the impact of ABS removal is not universal :)

[Wanganstyle]

Really? What does the e36 abs unit have inside it?

The e36 masters seem only slightly larger bore than e30.

E36 drives and tracks just fine with abs electronically inactivated; is the mechanical proportioning valve built into the e36 abs?

E30 brake feels more direct to actulate with the abs unit removed. Proportioning is separate from the abs unit and the abs master is happy with stock or 4 piston front brakes without abs unit attached

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[jlevie]

I've never really looked an an E36 brake system. And it may depend on what year of E36. I know that later production has a 4 channel system, where an E30 has a 3 channel system. The E30 has a bias valve for the rear breaks and the E36 may have the bias valve as a part of the ABS, because of the 4 channel system.

[wazzu70]

Really? What does the e36 abs unit have inside it?

The e36 masters seem only slightly larger bore than e30.

E36 drives and tracks just fine with abs electronically inactivated; is the mechanical proportioning valve built into the e36 abs?

E30 brake feels more direct to actulate with the abs unit removed. Proportioning is separate from the abs unit and the abs master is happy with stock or 4 piston front brakes without abs unit attached

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I'm not exactly sure what the difference is with the E36 ABS. I just know there is a difference. I don't drive E36s so I never cared to get the details. The E36 does not have a proportioning valve in the rear line though.

Lots of info on BF.c in the track section.

[jlevie]

I'm not exactly sure what the difference is with the E36 ABS. I just know there is a difference. I don't drive E36s so I never cared to get the details. The E36 does not have a proportioning valve in the rear line though.

Right. An E36, being a four channel system, has one line to each of the rear calipers. So the right place for the bias valve would be just before or in the ABS unit.

[stanhayward]

jlevie is correct. You need a larger master. These masters can BARELY handle a 4 pot BBK let alone a 6 pot.

Sent from my XT907 using Tapatalk 2

I have the IE 6 pot front and 4 pot rears and it has the best brake feel of any car and can stop on a dime

[Zesty Bonanza]

I'm trying to use the e90 brake server and e90 master cylinder but the master cylinder only has 2 brake line connectors wheras my e30 non-ABS car had a master cylinder with 3 brake line connectors. The car also has s50 engine swap and the calipers are Wilwood 6 pot front and 4 pot rear. Does using only 2 brake line connectors (with T adapter) mess up anything such as brake bias?

link e90 brake booster in s50 swap: https://www.r3vlimited.com/board/sho...422514&page=10

[Buff_e30]

I'm trying to use the e90 brake server and e90 master cylinder but the master cylinder only has 2 brake line connectors wheras my e30 non-ABS car had a master cylinder with 3 brake line connectors. The car also has s50 engine swap and the calipers are Wilwood 6 pot front and 4 pot rear. Does using only 2 brake line connectors (with T adapter) mess up anything such as brake bias?

link e90 brake booster in s50 swap: https://www.r3vlimited.com/board/sho...422514&page=10

Hi, Opposite problem, I'm trying to use an e90 booster in my 87' that HAS ABS, and I seem to have only one line running into my master cylinder's setup, its like connected to iteslf in 2 places (see pic)....

This is a stock pic i found on the internet but it shows clearly the setup i have in my car, the 2 lines from the main master go to like a "secondary"? master and there is only one line connected to it where the green circle is.....

How do I properly connect my e90 booster if I do not want to remove my ABS......is it even possible?