320i booster

[luis.e30325es]

in order for this to fit, i understand i have to alternate the rod that connects to brake pedal, but can i use the e30 brake master cylinder with this booster?

[I*Do*Werke]

yes

[e30polak]

IMO, after having a swap with the 320i booster, I recommend either running the iX one instead, or simply relocating your factory booster over to the right like some guys have done.

The 320i booster makes you lose most of your brake assist. I had to run a vacuum reserve canister in between the booster and the intake manifold to get stock brake feel again.

[I*Do*Werke]

^ Im going to be running the e21 booster on my swap. Is the brake pedal feel really that bad? and what kind of reserve canister did you use?

[samiam3356]

I have an e21 booster, 25.4 mc, with e36m brakes and its not that bad imo. Is effort increased? Obviously.

[I*Do*Werke]

which bmw comes with a 25.4 mc?

edit: found it, the e30 m3. is it plug and play or is there modification needed to fit the e21 booster?

[dude8383]

I've got a 7 series master cylinder and an e21 booster from treehouse...tracked the car about 5 times already and love the pedal feel.

It takes some getting used to on the street but its fine imo.

[samiam3356]

which bmw comes with a 25.4 mc?

edit: found it, the e30 m3. is it plug and play or is there modification needed to fit the e21 booster?

You need to make sure you get the right one with horizontal bolts not diagonal.

[luis.e30325es]

Thanks for input guys, I got the 320i booster even though all I needed was the o-ring between master cylinder and booster. Now I have power brakes, and they feel fine, well compared to manual brakes, they work great.

[DREWHALL]

So let me just bring this back up, because I started looking into master cylinders. The E30 M3 came with a 23mm master cylinder? While the larger cars came with a 25mm? My pedal is pretty stiff already due to the smaller E21 booster, but it seems to lack in the amount of effort transmitted to the calipers. Larger master cylinder would increase pedal stiffness, but also increase amount of hydraulic action? That seems to be what I'm reading all over. Looking to track the car soon and still be able to drive it on the street with no problem. Any advice before I order the wrong master cylinder is appreciated.

[samiam3356]

I wouldn't go past a 23mm unless you have upgraded your calipers to larger units that need the extra volume.

[DREWHALL]

That makes sense. I guess I'll go with the M3 unit and see how that works out. Thanks man.

[AndrewK]

I wouldn't go past a 23mm unless you have upgraded your calipers to larger units that need the extra volume.

I don't agree. It really just boils down to a matter of preference in pedal feel and position. Simply, the pedal doesn't need to travel as far with a larger MC.

Personally, I much prefer the feel of a 25mm master. Upgraded my E30 M3 years ago and loved it. So much so that I decided to run a 25mm on my swap with 325ix booster. The brakes in my swap car feel excellent considering they are still otherwise stock.

No experience pairing the 25mm to a 320i booster. So I can't comment on that specifically.

[DREWHALL]

Well that's the thing, the 320i booster reduces the assist so much already. The pedal feel isn't terrible but the amount of braking you get for the effort you put in is marginal. I've considered installing a Massive Brakes street kit in the front at least to get some serious brakes. I need to get my ABS wired up again though. I haven't had ABS since I did the swap.

[dude8383]

Whoops, I did forget to mention in my initial post that I have Lee's 280x22 kit up front!