Euro S50 and Brake Boosters

[Mike B.]

I've ordered a Metro booster to see what modifications need to be made. I'll report back when I have it in hand.

I know for sure you will not be able to use a BMW M/C. The stud spacing on the booster is different.

[trent]

Boring. Shoulda went my way. haha :)

[Mike B.]

If I had any sort of metal working skills, I would've. :)

[Massive Lee]

I've ordered a Metro booster to see what modifications need to be made. I'll report back when I have it in hand.

I know for sure you will not be able to use a BMW M/C. The stud spacing on the booster is different.

In my opinion, using the hydraulic booster from the e28 is the cleanest solution. If you use the booster from a domestic car, you will be forced to use a domestic MC. Please consider the hydraulic booster and the shorter e36 M3 MC. BTW I studied this problem high and low when I installed a Euro S50 in an e30 M3. My friend who owns the car also owns the shop that sold perhaps Euro engines in the last year. Some of them even reached the Chicago burbs...

[Mike B.]

Lee, I'm not real familiar with the E28 setup. Where did you mount the pressure regulator/accumulator and reservior? Does the shaft require any length adjustments like the 2002 or E21 boosters?

[Massive Lee]

This is what would replace the whole brake booster.

http://www.realoem.com/bmw/showparts.do?model=DC74&mospid=47231&btnr=34_0297&hg=34&fg=25

You can locate the hydriogen "bomb underneath. Go to any scrapyard and pick-up an assembly for cheap. It worth trying.

[Mike B.]

It looks pretty straight forward.

However, the reservoir on the far left of the real.oem diagram (no part#), where does the hose coming out of the bottom lead to?

[Massive Lee]

The reservoir is the same as is used to feed the steering pump. You will need this reservoir in place of the plastic one. Now, the power steering pump will feed the steering rack and the hydraulic booster. I have seen a couple of European conversions with the e28 system.

[Mike B.]

I assume it will have to be mounted above the "bomb" since it looks to be gravity fed, correct?

[1990m3]

sounds like a nice solution Lee, do you have any pics to show us how it came out?

[trent]

Looks like too much work when one can go manual and achieve better feel in the first place.

[Massive Lee]

Looks like too much work when one can go manual and achieve better feel in the first place.

A race car could indeed run a booster-less set-up with tandem pedal. I doubt anyone using the car as a daily driver will enjoy the extra effort.

[Massive Lee]

I assume it will have to be mounted above the "bomb" since it looks to be gravity fed, correct?

The bomb is indeed located lower.

[trent]

A race car could indeed run a booster-less set-up with tandem pedal. I doubt anyone using the car as a daily driver will enjoy the extra effort.

I dunno Lee, as we have discussed in email, my setup feels like a stock E30 M3 with a 25MM master cylinder. It is firm, but not too firm, and just right (I believe). Maybe a tad stiffer than the e30m3/25mm setup. I also drive the car daily. Under aggressive driving the modulation is fantastic, with no changes in feel due to boostr pressure differences.

The whole key though it to modify the brake pedal and related pressure. I doubled changed the ratio from 4:1, to about 6.25:1. Gaining that leverage is very nice. :)

[gstuning]

When I go S50 again,
manual brakes for me, anything else is just to much of a hassle,