FYI - the stock booster does NOT clear no matter how much you want it to

[Cyrix2k]

I heard one guy kept the stock booster without slotting the firewall.

then he modified the intake manifold to work around it

There was someone who shimmed their motor mount to make it work too. That seems like a really bad solution imo. I've also seen a few people complaining about the 944 booster, not just one. Honestly, firm would be fine with me but someone was complaining that it was "mushy." I'm fairly committed to the stock booster at this point.

[Jand3rson]

Fair enough. One of my chief reasons for going with the 944 booster was not only ease of install, but also because it's much smaller, and looks better in the bay. The stock one is quite a bit larger in diameter, where the 944 is a smaller diameter, just a bit thicker.

[Leo_328i]

Bit unnecessary to give him so much crap guys!

I bet a lot of people haven't gone to the extent of trying to melt part of their inlet manifold to try and make it fit so there is some sort of knowledge gained here.

[FredK]

A 944 booster with the stock master cylinder is not mushy, nor does it increase braking effort a whole lot. If you want to install an M5x with a minimum of drama, the 944 booster makes a whole lot of sense.

It could feel rock hard if you get a bad booster, or if you have a waning master cylinder, mushy.

A 944 booster with a 25mm MC isn't that great, but that's more an effect of the 25mm MC more than anything else. The effect is far more pronounced on a non-M E30, as the MC is a stepped bore 21/17mm vs the M, which is a single bore 22.2mm MC.

He deserves at least a little ribbing. There are numerous threads here about brake boosters, complete with pictures. A stitch in time saves nine.

[Mr.SWISS]

Well, I'm picking up the A4 18t non quattro booster and MC to fit it up. Seen it installed in one car and it made so much more room in the area where you may already have 6 inches of useless wire adapter plug wondering....How the hell am I gonna tidy up mah bay yo?!?!? So far I have found the only degree of difficulty added is putting the audi line needs on the bmw lines and then flare the fittings back.

[Philo]

EVERYONE READ THIS>

To properly displace oil throughout a 24v engine, the block/head must lay at 30 degrees from vertical. Be sure to take this into account when shimming up the engine, otherwise the oil will favor one side of the valve terrain as well as possibly starving the sump. With the engine placed at the correct angle, it is not possible to fit the stock 'I' booster, even after slotting the firewall over and trimming the baffles.

Just a friendly FYI and something to think about.

[motorsports_3]

So it should be shimmed 30 degrees to the driver side?

[Jean]

I want to see pics of you trying to melt the intake manifold!

[bloodshot-e30]

2001 audi A4 brake booster and MC FTMFW ;)

[FredK]

So it should be shimmed 30 degrees to the driver side?

No, it just needs to rest normally--meaning, on engine mounts that are around the same height, and on its stock mount arms.

[Cyrix2k]

EVERYONE READ THIS>

To properly displace oil throughout a 24v engine, the block/head must lay at 30 degrees from vertical. Be sure to take this into account when shimming up the engine, otherwise the oil will favor one side of the valve terrain as well as possibly starving the sump. With the engine placed at the correct angle, it is not possible to fit the stock 'I' booster, even after slotting the firewall over and trimming the baffles.

Just a friendly FYI and something to think about.

huh? Yes it is. Mine's sitting on the engine mounts right now... Good info though!

[Chrisv006]

EVERYONE READ THIS>

To properly displace oil throughout a 24v engine, the block/head must lay at 30 degrees from vertical. Be sure to take this into account when shimming up the engine, otherwise the oil will favor one side of the valve terrain as well as possibly starving the sump. With the engine placed at the correct angle, it is not possible to fit the stock 'I' booster, even after slotting the firewall over and trimming the baffles.

Just a friendly FYI and something to think about.

I must have a freak m50? Mine fit fine slotted with some fins shaved off the manifold for additional clearance. Hockey puck M5 mounts on both sides.

I dont see how a few degrees of tilt in either direction will not affect oil flow at all, as long as your pickup tube is submerged so your pump can supply oil to the needed componets. How does the engine survive continuous curvy road driving?

The topographical map of my valve terrain has been unaffected thus far :)

-Chris

[Mr.SWISS]

2001 audi A4 brake booster and MC FTMFW ;)

No pedal feel complaints from this swapper....

[Philo]

huh? Yes it is. Mine's sitting on the engine mounts right now... Good info though!

What mounts are you using, and are you using any shims?

I must have a freak m50? Mine fit fine slotted with some fins shaved off the manifold for additional clearance. Hockey puck M5 mounts on both sides.

I dont see how a few degrees of tilt in either direction will not affect oil flow at all, as long as your pickup tube is submerged so your pump can supply oil to the needed componets. How does the engine survive continuous curvy road driving?

I'm not sure what the "hockey puck" mounts are. If they are cylindrical, than those are taller than the E28 mounts most people use and might assist in clearance.

As far as the extra degrees, it would need to be more than a few to clear the I booster. Also, the engine would most generally need to be shimmed up on the drivers side, moving the intake manifold away from the booster, as well as the oil from the pump. This could cause starvation during left hand sweepers.

I'm not saying that you'll absolutely damage the engine. It is just something to take into consideration. I'm glad to hear your engine is still running strong.

[rThor432]

I didn't shim my engine mounts. Shims add weight and rob horsepower.