A different approach to the v8 swap brake booster...

[mr walker]

I've started looking at the v8 swap possibilities more over the past month. You guys are doing an awesome job in this forum; there's so much to be learned here thanks to you. The whole m62 bottom end+m60 heads thing has piqued my interest. One of the "more notable" obstacles with this swap involves the brake booster setup.

So I started thinking: is there any reason why you couldn't (or wouldn't want to) take a hydraulic approach with the linkage rather than fabricating a mechanical linkage?

What I have in mind is something similar to the clutch master/slave cylinder setup and applying it to the brake booster. I have more elaborate things going on in my head, but I first want to know if you guys think this even makes sense or is feasible.

Edit for clarity: I'm talking about still using the e34 booster/mc, but using hydraulics to actuate the push rod on the booster...think how the clutch pedal acts on the clutch fork via hydraulics. Assuming you can comprehend what's happening in the illustration below, it basically shows that with enough brake line and vacuum hose, you could mount the booster/master cylinder to your trunk if you wanted to. That's also assuming that this would actually work...

Coloring is fun:

[iamsam]

Yeah I think someone did a hydraulic setup somewhere on here, but it looked quite complicated.

[Jean]

Since the m6x is quite wide, the hydro booster setup needs to be custom fitted, less room in the engine bay vs the same setup as used in the LSx swaps.

[CHIF8008]

run the booster under the dash, problem solved

[bmwmech1]

Look at the right hand drive cars and make a mirror image copy of the linkage. Booster could go where the glovebox is, custom lines... Mike Hockman suggested I do that way back when... I just chose a different(read more elaborate) path...

Garey

[mr walker]

I'm talking about still using the e34 booster/mc, but using hydraulics to actuate the push rod on the booster...think how the clutch pedal acts on the clutch fork via hydraulics. I'm not really thinking about hydroboost (hydroboost in my mind is like what GM uses on some of their cars...using an engine driven pump to "power" the power brakes).

[sticksdaman]

I see what youre saying... Instead of the rod coming straight from the pedal, a master cyl a hose (or hard line) and then another slave cyl at the booster.

Id be interested to see how this may be setup as i am dreading the brake setup of this car.

[mr walker]

Yep, that's exactly what I'm thinking.

I believe the biggest issue faced with this idea would be properly matching the master and slave cylinders: you would (or at least I would) want to retain a semi-factory brake pedal feel and pedal travel. Otherwise, what's the point?

Thoughts?

[JGood]

A hydraulically driven vacuum assist system for hydraulic brakes. Sounds like something that belongs on a BMW at least! :)

IMO, the main problem in all of this is that there's no room for a firewall mounted master cylinder. Otherwise people would just a run booster-less setup with the proper pedal ratio to retain decent pedal feel.

And if you're going through the trouble of mounting the remote booster assembly, you might as well just make the changes to the pedal box and just run the whole e34 system. You'd only be skipping out on the easy part of the install, and would be creating a lot of work for yourself with a hydraulic setup to replace it.

Just my opinions, of course. If you think you can make it work, have at it! If nothing else, it will be a fun learning experience.

[mr walker]

^^I edited my OP to better describe what I'm talking about. While a hydroboost setup would be totally feasible for say, a Euro S50 swap, I understand that due to the width of the V8 you basically can't have anything where a master cylinder would normally reside. It's not just an issue of the MC and the booster being there...nothing can be there.

I'm going to make a hilariously bad mspaint picture later to better illustrate what I've got in mind.

[sticksdaman]

'scribed!

[mr walker]

Meant to edit OP, sorry.

[JGood]

^^I edited my OP to better describe what I'm talking about. While a hydroboost setup would be totally feasible for say, a Euro S50 swap, I understand that due to the width of the V8 you basically can't have anything where a master cylinder would normally reside. It's not just an issue of the MC and the booster being there...nothing can be there.

I'm going to make a hilariously bad mspaint picture later to better illustrate what I've got in mind.

I know you didn't mean a hydroboost setup. If you want to find a home behind the firewall for your 'booster master cylinder', you've got your work cut out for you. You'll need to create some pretty solid brackets/linkages, probably more complex then what I had to do to get the e34 linkage connected to my pedal box.

I guess I just don't understand the reasoning. The main draw back to the e34 setup is the bulkiness of the booster and it's bracket. The linkage leading up to it occupies a space that is otherwise unused... the area just above the frame rail in front of the firewall. And it all basically bolts right in. You're bypassing the easy part of the e34 booster install, and replacing it with a rather complicated hydraulic system.

If you're doing all that, why not just throw in a Tilton/Wilwood pedal setup and call it a day? It's the easiest solution, the only drawback being your M/C's are inside the car, making replacement messy... but with your idea, you're doing that anyway...

[Jonsku]

Using "three brake cylinders" is a good idea that has been around for a while. As Garey said, the best option would be to mount the "first cylinder" somewhere under / over the glovebox with RHD-linkage (just played with one couple of weeks back, it's very simple and solid construction).
True pedal box is something totally different, so it should not be mixed with this.

I'd say this approach tidies up the engine room quite a bit as you could mount the booster itself to trunk for example, which gives you lots of more space to the engine bay (e.g. for S62 intake pipes, turbo or SC applications).

Maybe it's not the best solution for typical "bolt-on M60 applications" but for more exotic solutions it might well be viable thing to consider.

[JGood]

Ahh, I overlooked the mention of a trunk mounted booster in the OP. That would be nice if you don't require the trunk space. I think a guy on this forum who swapped in a Toyota V8 did that. I agree, it would be nice to free up the engine bay space.