audi a4 1.8t booster/mc *update it's installed!*

[marek|steezkal]

This booster with an upgraded 25.4 mm S4 MC feels amazing on the pedal. I haven't driven the car yet but just compressing the pedal has a good feeling to it.

Reviving this thread. Any update after driving the car? I'm interested in the Audi booster option as there are many part outs here in CO.

I do have a question regarding the MK3 reservoir, does it have a connection for the clutch? The pictures in this thread did not show whether it has it or not.

[nrubenstein]

I'm trying a Mercedes W203 C230 booster next. Same size, but a much better master cylinder match. (23/20 and 25/20 available).

If that doesn't work out, I think it'll be a firewall mounted and slid over iX booster.

The C230 master looked good, but the booster would require the rod to be welded.

iX booster it is. It'll be interesting to see how the thing dynos. Hopefully I haven't lost too much power.

[Mistawall]

What's the part number on that thing


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[nrubenstein]

why would an ix booster need to be slotted over? you running a non stock intake manifold?

See my sig. Euro motor. And heavily modified to make it work.

[SmokeE30]

I'm trying a Mercedes W203 C230 booster next. Same size, but a much better master cylinder match. (23/20 and 25/20 available).

If that doesn't work out, I think it'll be a firewall mounted and slid over iX booster.

why would an ix booster need to be slotted over? you running a non stock intake manifold?

[nrubenstein]

I'm trying a Mercedes W203 C230 booster next. Same size, but a much better master cylinder match. (23/20 and 25/20 available).

If that doesn't work out, I think it'll be a firewall mounted and slid over iX booster.

[5mall5nail5]

My E30 swap has pretty unassisted brakes using the E21 booster. Debating on swapping something else in but I don't think this will be it...

[nrubenstein]

So far, awful. No matter what I do, I can't get it to bleed. On top of that, I have now had a second booster that appears to be leaky as fuck.

It's looking like I will be going back to the 924 booster, unless I can figure out another solution.

[Rook12V]

Anyone have any updates on how this feels while driven? I've got the UUC big brakes on my E30, with the 7er master cylinder. Right now my brake pedal feel sucks. I have to stand on my brakes to slow down. Its very firm but there isn't a lot of stopping without tons of pressure. I hate it. I want more boost, wondering how this setup feels as I'm thinking of going to it when I put my S50 in.

[nrubenstein]

Mechanically speaking, how would bottoming it out trash it? Seals rip while passing an opening?

I assume so. Or an unmachined portion of the bore.

Either way, it's kind of important to be aware of. The booster is roughly an inch smaller in diameter than the iX, so it's a huge clearance improvement for me. It makes it actually possible to use my (modified) S50B32 manifold.

[ForcedFirebird]

Mechanically speaking, how would bottoming it out trash it? Seals rip while passing an opening?

[nrubenstein]

.....aaaaaaaaand another VERY important piece of information:

If you bottom out the master cylinder, it's trash. Apparently the Audi guys toss a piece of 2x4 under the pedal when bleeding the brakes. You also need to be very careful after swapping pads. Absolutely fucking bizarre. Unfortunately, there doesn't seem to be anything else that's close to the diameter, or I would toss it.

Edit: And by "trash," I mean that it can't muster enough brake pressure to stop me from rotating a front wheel one handed.

[nrubenstein]

As an FYI, make sure you match the booster to the MC. In 99, they switched them out and they are NOT dimensionally interchangeable. (The early one bolts up to the late booster, but you will have a lot of empty pedal travel before it actually brakes.)

[ZekeTheSneak]

just a heads up, this same part comes on 1.8T passat B5's, 2.7T Audi A6's and S4's, with either a 23.8mm master or 25.4mm master. i picked up a booster/mc the other day from an A6 for $60 :up:

Hell yeah, I think I'm into my setup 70 bucks? Very affordable and common.

[mtlbloodshot]

The one I got had a 23.8mm so I got myself the S4 one 25.4mm just because... Im sure the 23.8mm is enough to do the job tho.