Comprehensive brake booster thread for S5x and M5x swaps

[eternal24k]

-Year and model of your E30: 1991 318i
-Intake manifold used in swap: M50/S50
-Brake booster manufacturer and manufacturer PN or identifying marks: BMW E83 X3 Brake booster, TRW manufactured
-Parts needed: M12 brake line adapter (I used AGS BLF-48C-5)
-Modifications needed: Need brake line adapters above for the E83 master cylinder, reduced diameter of rod and threaded for E30 joint, if i was going to do this again, would have drilled and tapped the E30 bracket.


More info and pics here

[NvE30]

-Year and model of your E30: 1991 318is
-Intake manifold used in swap: m50 OBD1
-Brake booster donor car: 2009 e90
-Brake booster part number: (if known)
-Brake booster manufacturer and manufacturer PN or identifying marks: stock e90 booster
-Parts needed: no parts needed, used e90 booster and master cylinder
-Modifications needed: used the U-shaped e30 booster pedal bracket and welded it to the U-shaped bracket on the on the end of the rod on the e90 booster. It ended up being an exact fit. No cutting or re-threading needed. I did have to shave down a couple of fins on the intake manifold as they were almost touching the booster.

see my post about the subject here:

https://www.r3vlimited.com/board/showthread.php?t=430062

[irish44j]

Year and model of your E30: 1985 318 (formerly M10, formerly M42)
-Intake manifold used in swap: M50TU (e34)
-Brake booster donor car: Porsche 944 (ATE)
-Brake booster part number: The ATE one
-Brake booster manufacturer and manufacturer PN or identifying marks: ATE
-Parts needed: None.
-Modifications needed: Just had to thread the rod down a couple inches and then cut it off. Otherwise was direct bolt-up to firewall, to e30 M/C, and to pedal. Had to slightly shave IM. I'm using Condor solid mounts plus a couple washers, so plenty of clearance.
-Comments on pedal feel and stopping power: Some people say it has "less boost" than stock e30, but I actually think it feels better. That said, my e30 booster was old/original and this one is brand-new, so who knows. My brakes feel better than ever
-Other info: 1" smaller than stock e30, as we all know.

[Massive Lee]

Hi Marc

I looked into your problem yesterday. While your swap is common and that people use successfully the 944 booster, the problem comes from your lowered engine with the revshift mounts. On a regular fitted motor, the booster sits right below the plenum's corner. Filling the fins is all that is needed. In your case, the plenum sits lower, and causes the interference. My suggestion is to move the brake booster by an inch toward the suspension tower. It can be done by redrilling the firewall, fitting a blocking plate, and drilling the brake pedal. use an M8 rod end instead of the clevis. The rod end shall be fitted IN the brake pedal. Call me tonight if you need details. I'll give you a female rod end. David can drill the pedal and cut the orignal tab... ;-)

[Marc124444]

Help please!

Swap s52 in e30 1987

S50 intake

Use the Porsche Brake booster, too big I cannot fit the intake :(

The motormount are the Revshift and the engine is sitting lower.

I would need at least one inch less.

I dont want to run booster less ... even if it’s a Race car

[sebe20]

Year and model of your E30: 1986 4 door
-Intake manifold used in swap: M54B30 intake manifold
-Brake booster donor car: E34 525i
-Brake booster part number: (unknown)
-Brake booster manufacturer and manufacturer PN or identifying marks: Lucas/girling
-Parts needed: tandem brake booster, E34 5 series master cylinder (or Mercedes master cylinder if you want to keep oem brake lines and routing) E34 or Mercedes reservoir
-Modifications needed: brake booster spacer has to be bolted off, pushing rod shortened approx 5cm and re-threatened. 2 holes in firewall have to be drilled larger.
-Comments on pedal feel and stopping power: pedal feels sharp and stiff after a few pumps.

[HCMW Adam]

I am looking through the ATE website about the OEM brake booster and looking for the booster force, or ratio, or whatever you want to call it that a booster does. Coefficient of pushing the pedal maybe. There is Parameter T52. I am guessing that this means 5.2 ratio of increase. That is a complete guess.

[Staszek]

This thread is awesome.

https://www.r3vlimited.com/board/showthread.php?t=422514

It's for a big brake setup though.

Thanks, I have a BBK.

[RainRider]

Bumping an old thread. I have a 2002 booster but before I go and get the engine in I am having second thoughts.

Has anyone successfully done the E90 booster swap? Seems like best of both worlds.

This thread is awesome.

https://www.r3vlimited.com/board/showthread.php?t=422514

It's for a big brake setup though.

[Staszek]

cwlo is using it on his N52 swap. IIRC he's using an E83 MC.

Thanks I reached out to him. I will have to check his posts on his swap. Is he using the X3 reservoir ?

[nando]

cwlo is using it on his N52 swap. IIRC he's using an E83 MC.

[Staszek]

This is the first I've heard mention of using an E90 booster. Has anyone done this swap?

The diameter seems perfect and I am curious to know if it is a straightforward swap of if fabrication is involved...

As said above, it would be nice to have a newer more common booster to use for the swap.


MJ

Bumping an old thread. I have a 2002 booster but before I go and get the engine in I am having second thoughts.

Has anyone successfully done the E90 booster swap? Seems like best of both worlds.

[digger]

Austin! - I just acquired a 325iX booster.

Did you mount with or without the bracket? Is the 25mm master required or just an upgrade - I was under the impression that the stock master could be re-used.

Sorry for the Noob questions but I want to get mine right first time.


Thanks,

MJ

can you confirm that the 325ix booster is only 1" small OD than the standard 325i booster?

[mjweimer]

Austin! - I just acquired a 325iX booster.

Did you mount with or without the bracket? Is the 25mm master required or just an upgrade - I was under the impression that the stock master could be re-used.

Sorry for the Noob questions but I want to get mine right first time.


Thanks,

MJ

-Year and model of your E30: '89 325is

-Intake manifold used in swap: M50/S50 - shaved fins for extra clearance

-Brake booster donor car: '88 325ix

-Brake booster part number: not off the top of my head

-Brake booster manufacturer and manufacturer PN or identifying marks: Girling or ATE

-Parts needed: E34 M5 25mm master cylinder, 2002 brake fluid reservoir, grommets and connectors.

-Modifications needed: this is a bolt on affair for e30s, the way I did it. No changing of the lines, no slotting the firewall, no modifying the clevis rod. Just a simple brake pedal adjustment at the end to adjust the pedal placement for the switch.

-Comments on pedal feel and stopping power: this is the best setup and frankly, the only way to do this job. With the 25mm master cylinder, it is a bit touchy, but has great pedal feel and superb response. Done over two dozen of these conversions and it is the best way I've found. Certainly not the cheapest, but if you want it done right...

-Other info: Booster diameter or other dimensions. Any other helpful info.

[e30austin]

-Year and model of your E30: '89 325is

-Intake manifold used in swap: M50/S50 - shaved fins for extra clearance

-Brake booster donor car: '88 325ix

-Brake booster part number: not off the top of my head

-Brake booster manufacturer and manufacturer PN or identifying marks: Girling or ATE

-Parts needed: E34 M5 25mm master cylinder, 2002 brake fluid reservoir, grommets and connectors.

-Modifications needed: this is a bolt on affair for e30s, the way I did it. No changing of the lines, no slotting the firewall, no modifying the clevis rod. Just a simple brake pedal adjustment at the end to adjust the pedal placement for the switch.

-Comments on pedal feel and stopping power: this is the best setup and frankly, the only way to do this job. With the 25mm master cylinder, it is a bit touchy, but has great pedal feel and superb response. Done over two dozen of these conversions and it is the best way I've found. Certainly not the cheapest, but if you want it done right...

-Other info: Booster diameter or other dimensions. Any other helpful info.