Victorymike18

It's always great to see these updates.

That's a nice chunk of progress, and I think you'll be better-off in the long-run with the more "normal" vacuum brake booster.

The polished bracket looks great as well, very nice!

Good question about the green foam. That makes sense to me that it would be to allow the back side of the booster to breathe.

MarkDoronin

Thank you for your work and for sharing the results - it's very cool!

desertsage

You're welcome, Mark! Thanks for your interest. There is more to come, as I find the time to post here.

desertsage

I've come to a roadblock with the vacuum brake conversion. The ABS module was interfering with the booster install. I had to temporarily remove the module in order to get the booster to move past it. However, after the booster was fully seated against the firewall I was not able to reinstall the ABS module. The module would have to be moved forward at least an inch in order to reinstall its mounting bushings and to get the brake lines reinstalled.

Another area of interference is that the booster is very close to the distributor. I'd probably have a tough time removing the cap and wires, and certainly wouldn't be able to remove the distributor itself without first removing the booster.

This is a mystery, as I know that these tandem boosters will mount to the B3 using the Ultra Performance kits, but maybe not with ABS? I've received some advice from my local vintage Audi group to switch to a booster from a B4. I now have one on the way, but am not happy about having to give up the tandem booster plan.

See the photos for examples of the mismatch.

desertsage

Going back in time a little, I had not yet documented my power steering fluid cooler install. Another "unintended consequence" of moving the radiator forward for the fan clearance, was that I could no longer use the stock PS fluid cooler. The cooler does not need to be substantial in order to perform the same level of cooling that the stock cooler had taken care of, so I looked for the smallest oil cooler I could find. One that could also be mounted in the limited space. Running lines to and from the cooler proved to be a challenge, but I eventually pulled it off after some trial and error.



Fabricated brackets from aluminum bar stock. They are basic, but work.




10AN fittings using Push-Lok hose.


I had to put a loop in here to allow for engine movement. It probably didn't have to have a swoop quite this long.

grillage

The B4 booster is way shallower but bigger around. I'll bet it will fit

grillage

here are the two boosters together -- B4 and the later tandem style



On the fan issue mentioned above.

here are the 7a and the RS2 fans/shrouds side by side. the RS2 is way more powerful and also shallower

desertsage

Hey grillage! Thank you so much for the photos and interesting comparisons! I had been looking for something like this. It looks like your tandem booster also has an adapter from Ultra Performance Engineering.

Hopefully the 2 speed Derale fan I've installed (earlier in this thread) will move the air adequately.

grillage

Correct, I have since sold my B4 - I went to the tandem setup because I upgraded the brakes to much larger spec. It's a great kit!

desertsage

Can you tell me which Audi model or chassis you had sourced your tandem booster from? C6?