E30 M50 swap with E90 booster

[MFresh2089]

MFresh2089 did you buy from the UK and have it shipped over? Was shipping expensive?

i bought it form ebay.. $75 shipped and arrived in 4 days to NC.. See below link to the seller..

https://www.ebay.com/usr/globalparts...72.m2749.l2754

[hoveringuy]

I have the X3 version which is prettier. I don't know if they all have the same MC size, this one is 25.

[eternal24k]

I used X3 booster and M50 intake manifold, fit right up with the X3 reservoir

[Goupan]

I don't hear anyone talking about the different mounting points; the e30 booster has 4 bolts going through the firewall while the e90 has two. They are also differently sized in terms of space between the bolts. Do people just drill extra two holes and call it a day?

[moatilliatta]

E83 has the lines on left hand side of the car.

https://www.r3vlimited.com/board/forum/e30-technical-forums/24v-engine-swaps/m50-52-s50-52/292299-comprehensive-brake-booster-thread-for-s5x-and-m5x-swaps

https://www.r3vlimited.com/board/forum/e30-technical-forums/24v-engine-swaps/m50-52-s50-52/379328-m50-swap-that-will-blow-your-mind

https://www.r3vlimited.com/board/forum/general-forums/members-rides/9901249-1989-325i-s50-swap-project

[maaaad]

Also RHD versions of e90 have the lines on the left side of the car. In my case it was nearly impossible to fit brake lines on the right side (as far as I remember - they collided with throttle cable), so I bouht an RHD master cylinder; everything looks better, fits better.
If someone is interested - BMW f10 expansion tank/reservoir fits quite nice, straight from the box (with m52 throttle body - not sure if it will fit as good with m50 tb) - P/N 34 33 6 782 289:

[cirrusblau87]

Same question as Goupan re: the mounting points. Did you guys end up drilling 2 new mounting points on the firewall?

[twright]

Same question as Goupan re: the mounting points. Did you guys end up drilling 2 new mounting points on the firewall?

You don't have to drill two extra holes. Take the two nuts off that hold the plate on that E90 booster. Voila! Now you have only two studs.

[cirrusblau87]

twright Thanks!! I'll share my experience with this when I get it set up.

[DatBxE30]

Hey guys !! Nice write ups. I’m in the middle of doing a m52 swap and ordered the e9x booster. Can someone point me in the direction to pick up a custom clevis pin ? Thanks

[maaaad]

Hey guys !! Nice write ups. I’m in the middle of doing a m52 swap and ordered the e9x booster. Can someone point me in the direction to pick up a custom clevis pin ? Thanks

I cut off the original fork (just the fork!) from the booster, threaded the rod and used a new e24/e28 forkhead (p/n 34331150988, ~6 $ at Turner Motorsport, eg.). I don't remember if I was grinding the rod (wasn't it a bit too thick), but I made the thread the same as e30 fork. Then I used an original e30 clevis pin and so I also have a MC/brake pedal adjustment, just as it was before swap.

[Buff_e30]

2 questions:
So The e90 fork is for sure too big with ANY size/length clevis? Nervous to weld e30 fork on for fear of heat cooking something inside the new booster.

Is it possible to pull the rod from the e90 booster for welding or threading work?

[mjweimer]

The rod is too long and the clevis is too wide. I guess you could shim for the width but the length will still be problematic.

I did not see a way to remove the rod on my E83 booster without taking apart the canister, the E90 should be similar. I drilled out a nut and tack welded it on the rod below the area to be threaded. This let me hold the rod steady for threading and I simply cut it off when done. I suppose vice grips could also work or maybe the right set up in a bench vice. It takes some creativity.

[Northern]

I've been told you can cut off the E90 booster fork and rethread it to accept a 34331150988 clevis/fork from some kind of euro E23/E28 I think?

Supposedly it is just longer than the E30 one. I ordered, but it's taking its time in shipping.

[hoveringuy]

I cut the E90 clevis off, threaded to e30 and used the E30 clevis, but it's not quite long enough and the brake pedal sits a hair too low.
I've also ordered the 6 series one and it's backordered for at least another month.
How much longer is that one? (E30 is 44mm?)