Comprehensive brake booster thread for S5x and M5x swaps

[AWDBOB]

Does anyone know if this is this the proper ATE 944 booster w/ 10mm rod?

http://www.partsgeek.com/gbproducts/...ad=47433965052

Answer: yes

helpful thread: https://www.r3vlimited.com/board/showthread.php?t=98602

[nando]

FWIW some booster diameters. Thought this would help to add so people know how much room they are gaining for the effort.

E30 (non ix): 11"OD/10" diaphragm

2002 (non-tii): 8"OD/7" diaphragm
2002tii: 7"OD/6" dual diaphragm
E30 ix/E32: 10"/9"OD/ 9"/8" dual diaphragm
E36: 11"OD/10" diaphragm
E46: 11"OD/10" diaphragm
E46M3: 10"/9"OD/ 9"/8" dual diaphragm
E90: 9"OD/8" dual diaphragm
Porsche 924/944/951: 10"OD/9" diaphragm
Mk2 VW: 10"OD/9" diaphragm

that's good to know.. even though I already have the ix booster, I'm still worried about manifold clearance - the E90 booster would give me another half inch clearance, and they should be easy to find (and also not 30+ years old).

[wazzu70]

Yeah, I looked all over to compile the data so I figured I would post it for reference. The not being 25 years old thing can be nice too!

[mjweimer]

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

[nando]

probably the clevis needs modified, but usually that's pretty easy with basic tools.

[bradmer]

E90 Booster

Can this really be done? Any photos of an install out there?

[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.

[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.

[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?

[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.

[nando]

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

[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 ?

[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]

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.

[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.