Euro S50 and Brake Boosters

[erik325i]

Update: The 924 booster fits, but I can't source a M/C that will clear the intake boot. The complete assembly is just too long and rubs the intake boot.

What masters have you tried?

I went out and got the 924 booster a week ago for my swap car, all excited thinking it will work. Ohh well...

-Erik

[Mike B.]

I am doing a Euro swap, which is a completely different animal than the US-spec engine swaps.

In your case, the 924 booster should be fine.

[erik325i]

I am doing a Euro swap, which is a completely different animal than the US-spec engine swaps.

In your case, the 924 booster should be fine.

I know you are doing the euro swap... I'm hoping to get my s50b32 in a few months... ;)

-Erik

[Mike B.]

Nice!

[gstuning]

Very nice craftmanship. But let's not forget that a race set-up and a street set-up would be very different. Tilton/Wilwood boosterless pedal systems are great for racing, as you don't care how hard you have to push the brake pedal. For a street set-up, it would be a very different ball game. And dangerous at that, especially in city traffic.

I would not recommend that set-up for street driven cars. The effort required to effectively brake a car is much higher than a booster set-up. Let's not forget either that race set-ups usually come with bigger double 1.75" piston calipers, which are close to 60% bigger than stock... and make braking easier, and race pads have a lot more grip than street ones, when hot obviously.

For those who are installing a Euro S50B30-B32, what is wrong with using the much shoretr e23 hydraulic booster and MC as mentionned by some, or the tiny bit longer e28 version (at tab bit longer)?

The E28 longer version most certanly doesn´t fit well
THe shorter ones just barely fit, and you still have to bend the metal plate in the intake boot a little,

I went trough 3 P/S when playing with that stuff ,
the feel was never nice,
If you guys had gone manual , you´d be done by now :)

[FredK]

Gunni, what is 3 P/S?

[Jason89i]

here is some additional information on the geo / suzuki boosters and masters. some combo's work, some dont, some need work. just posting for as a reference.




MASTER CYLINDER COMPARISON

91 AISIN MASTER (metro) – only fits aisin booster
(3 brake outlet ports – 1 front / 2 rear?)
Overall length = 4.125” (+booster)
Volume = Bore diam 13/16” ( 20.64mm) x +/-30mm travel.

96 AISIN MASTER (some trackers)
(3 brake outlet ports – 1 front / 2 rear?)
Overall length = ????”
Volume = Bore diam 15/16” ( 23.81mm) x +/-30mm travel.

96 AISIN MASTER (sport) – needs 1/8” spacers to fit aisin booster.
Aisin booster rod (master side) is 1/8” too long.
(2 brake outlet ports – 1 front / 1 rear)
Overall length = 4.0” (+booster)
Volume = Bore diam 1” (25.4mm) x +/- 30mm travel.

89 E30 M3 MASTER – fits e30 / e21 boosters
(2 brake outlet ports – 1 front / 1 rear)
Overall length = 6.5” (+booster)
Volume – Bore diam 25mm x +/-35mm travel. =n

91 HONDA 2.0i MASTER verify fitment w/ booster
Overall length =
Volume = Bore diam 15/16” (23.81mm) x +/- ????? =




BOOSTERS COMPARISON

E30 stock booster
10.75” diam x 4.5” thick (firewall to master mounting face)
Firewall mounting holes = 2-7/8 x 2-7/8”
Firewall center hole req’d = 2.37”
Firewall to end of threaded rod = 4.125” (m10x1.5)
Master studs = 2.37” c to c
Master bore hole = 1.67”

E21 320i stock booster
9.5” diam x 3.5” thick (firewall to master mounting face)
Firewall mounting holes = 2-7/8 x 2-7/8”
Firewall center hole req’d = 2.37”
Firewall to end of threaded rod = ?????” (m10x1.5)
Master studs = 2.37” c to c
Master bore hole = 1.67”

Aisin booster – early (1995?)
7.625” diam x 3.0” thick (firewall to master mounting face)
Firewall mounting holes = 2-3/8 x 3-1/8” wide
Firewall center hole req’d = 2.35”
Firewall to end of threaded rod = 3.125” (m10x1.25)
Master studs = 3-1/8” c to c
Master bore hole = 1.61”

Aisin booster – late (1991?)
6.5” diam x 2.75” thick (firewall to master mounting face)
Firewall mounting holes = 2-3/8 x 3-1/8” wide
Firewall center hole req’d = 2.35”
Firewall to end of threaded rod = ?????” (m10x1.25)
Master studs = 3-1/8” c to c
Master bore hole = 1.61

[FredK]

Thanks for posting the pics and the info Jason.

Hopefully by the year 2012 when I finally do an S54 swap, this info will become useful! :mrgreen:

[gstuning]

Gunni, what is 3 P/S?

Power Steering pumps was what I was trying to say

[erik325i]

Does anyone know the size difference between the stock e30 325i Master cylinder and the 25mm master cylinder? Or do they have the same dimensions?

-Erik

[Mike B.]

The stock or the 25mm M/C won't work with the 924 booster. The whole assembly is too long. The booster depth is ok, but the length of the M/C kills the whole deal.

To use either of these M/C's, you will have to either move the booster more towards the drivers side of the car, or move the intake boot forward on the plenum (I think Ian may have had this done for his swap).

Manual or Geo is the way to go for simplicity on a euro swap.

[Jason89i]

Does anyone know the size difference between the stock e30 325i Master cylinder and the 25mm master cylinder? Or do they have the same dimensions?-Erik

same dimensions.....but......one of the brake line ports has a larger diam. fitting than the non-m e30's. (seen in the pic above.) you will need to replace one hard brake line between the master and abs unit. no big deal. cost $6 at the dealer. jason

[Mike B.]

The E30 prototype for a dual master cylinder bracket should be in my hands by Friday. I'll post some pictures of actual fitment once it is in place.

It will incorporate Tilton (possibly Wilwood) master cylinders, and balance bar. It will mate up with the stock pedal cluster. No fabbing necessary (other than bending new brake lines), this part will be bolt-in!

[ian332isport]

...or move the intake boot forward on the plenum (I think Ian may have had this done for his swap).

I did indeed :)

[erik325i]

Ian, what booster and master cylinder did you use?

-Erik