vacuum reserve canister e21 booster

[sludge1300]

I've heard multiple mentions of adding a vacuum reserve canister (http://www.jegs.com/i/JEGS+Performan...63010/10002/-1) to improve braking assist.

Unfortunately it seems that all the fittings associated with this canister are for 3/8" ID hose. My setup requires 1/2" (12mm). M50 manifold ==> e21 Booster.

Anyone deal with this same issue? These websites are so cryptic about the sizes of all their fittings.

Thanks!

6/8/12 summary and update:

-I bought reserve canister and installed it.
-Noticed no reduction in pedal effort. Note: It was a long time between track days with and without canister, but during the last two weekends at the track, braking still required SERIOUS effort (running Carbotech XP10)
-Not enough back to back experimentation to say whether it improved consistency of braking force
-I ordered a brand new 944 booster, and plan to leave canister in to see if it improves consistency at all.

[I*Do*Werke]

Im also looking for the same thing. Ill post here if I find something usefull

[e30polak]

Use a hose clamp and call it a day. Vacumm lines are dirt cheap, and so are small hose clamps.

I ran this summit one on my car, and used on hose size, with no issue.

http://www.summitracing.com/parts/MRG-3701/

A vacuum reserve canister is a MUST IMO for the e21 booster. Without one, the lack of brake assist for spirited street driving is scary as hell!

[samiam3356]

Can you show a picture of your setup with this?

[e30polak]

Sold my swap car early 2010. My dad made me a custom bracket that placed the canister horizontally underneath the master cylinder.

As far as routing the vacuum lines, it's really easy. The vacuum line that runs between the intake manifold and the booster is basically cut in two, with one end (from the booster) going into one of the canister fittings, and the other one (from the canister to the manifold) goes to the second fitting. Result = double the volume of vacuum, bringing better then factory booster pedal feel and effort! :D

[samiam3356]

Would have like to seen that second vacuum line.

[e30polak]

Would have like to seen that second vacuum line.

Not pictured in the for sale ad, is the other fitting that goes in the second hole on top. You run the second vacuum line from that fitting, to the nipple on the intake manifold.

Here is a pic of how it goes:



Uploaded with ImageShack.us

[DREWHALL]

I wonder if that would fit where the OEM charcoal canister was. Might actually solve the issues I'm having for less than half the price. I'm considering changing my master cylinder with the E21 booster but this might do what I'm looking for.

[jrdeamicis]

The vacuum booster won't help with extra braking. It would help if you had a lumpy cam that didn't make much hg at idle.

But to make this work

Any good hoses and fitting place will have hose reducers (M and M nipples) on both ends to reduce down the size of hose.

[kingston]

Any good hoses and fitting place will have hose reducers (M and M nipples) on both ends to reduce down the size of hose.

Mmmmm...M&M nipples. I'd eat those

[Van Westervelt]

I was planning on doing this to my swap car, but with the e21 booster, 25mm master cyl, and larger m3 and e36 m3 brakes, it wasnt ever too much of an issue. I credit the larger MC as it pushed more fluid. A lot of people said that the 25mm master on stock m20 cars is too much.

So you might give a new master a try first, then try the secondary reserve tank.

[bubbajan21]

Result = double the volume of vacuum, bringing better then factory booster pedal feel and effort! :D

The vacuum booster won't help with extra braking. It would help if you had a lumpy cam that didn't make much hg at idle.

So, will this vacuum reservoir + E21 Booster = normal pedal feel or not?

[DREWHALL]

I'm having trouble deciding to try this, I'm not quite sold on the idea that this will increase the assist. I feel like I should still change master cylinders.

[samiam3356]

If you change to a larger MC the pedal is going to feel harder not easier. You are pushing more fluid with the same leverage. Unless you are changing to a smaller MC.

[sludge1300]

I hooked it up this weekend. I think it helps, but I only tried it with my track pads in the neighborhood, so I can't be sure. It is definitely not any worse though.

I just wrapped some electrical tape around the (3/8") fittings, and clamped the larger hose (1/2" ID) over them. No leaks....

I'll report back after I try it at the track, or just drive it some more and get a better impression.