My Audi-Based Big Brake Project - Fronts Only (Pic Heavy)

[Forthwithtx]

This is the story of my Audi-based Big Brake Kit. It was a cooperative effort between myself and a good friend of mine, who is an Aerospace Engineer (and happens to have a machine shop in his garage!).

Obviously, a great debt of thanks goes out to him, and the giants who have done this first, and detailed it on this forum.

I could not have done this without them.

The goal for this project was to get the largest rotors possible inside the 16" Mefro style steel wheels I'm running.

Some folks have just drilled out the G60 carriers and re-threaded them for the Vanagon uprights (with spacers), but I think that leaves you with a smaller rotor (something in the 278mm range) and/or grinding of the inside of the calipers to make clearance. This project bumps that out to 288mm with the unique adapter bracket design.

Everyone has different wheels or requirements, so I'm just documenting what we did. I'm fairly confident this is the best way to get 288mm Audi rotors into the smallest overall diameter.

The photos should tell the bulk of the story, but I will fill-in details and edit as necessary to make sure the narrative is clear.

From this:

Early rotors:

Late rotors:

To these Audi 288mm rotors:

Centric part number:

Planning:

_________________
Cheers!
-Karl

'84 GL with 2001/2004 Subaru 2.5L

[Forthwithtx]

Putting together the parts.

Not all Girling 60 (G60) calipers are the same. These are left and right calipers, but you will notice that they have bleeders on the same end, as some Audi’s have the calipers on the leading edge of the disc. I returned the one on the left and bought the opposite of the one on the right (note: the photo makes them look like they are different in size, but they are the same). For reference, I used the Centric 131.66059 and 131.33060 calipers.

My van is an ’84, so I had to source ’86-up spindles, the reason being that the '86's and later spindles are machined for carriers on the correct side, and the brake shields are different. In this case, I'm actually using ’86 spindles:

Comparison of parts:

My’84 setup:

The difference in the surface area of the pads is pretty dramatic!

The goal:

_________________
Cheers!
-Karl

'84 GL with 2001/2004 Subaru 2.5L

[Forthwithtx]

Cutting the Rotors into hubs.

This is the setup used for ’84 rotors:

And for ’86 rotors:

Side-by-side (one looks a tad thicker in the flange, but could be chalked up to variability between manufacturers):

They are, essentially, the same after machining and either could be used interchangeably:

_________________
Cheers!
-Karl

'84 GL with 2001/2004 Subaru 2.5L

[Forthwithtx]

Checking hub to rotor fit.

Turned hub OD to a couple thousands smaller in diameter than the ID of the rotor:

Needed a hub-centric ring (aluminum):

_________________
Cheers!
-Karl

'84 GL with 2001/2004 Subaru 2.5L

[Forthwithtx]

Engineering the caliper adapter bracket.

Engineering tools!

Trial and Error. We had to make the calipers fit over the big rotors and inside the 16" Mefro-style steel wheels from GW:

The final design:

_________________
Cheers!
-Karl

'84 GL with 2001/2004 Subaru 2.5L

[Forthwithtx]

Making the final bracket design out of steel:

Spacer made for fit checks only. Spacers are required to provide clearance for the caliper. We chose 8mm:

Why you need a spacer (close):

Fit checks:

_________________
Cheers!
-Karl

'84 GL with 2001/2004 Subaru 2.5L

[Forthwithtx]

Parts sent off to the platers to be yellow zinc plated (I gotta say they look fantastic!):

The original caliper bolts were cut down in length so they don't protrude through the adapter bracket.

Note one rotor has a slightly different cut (groove near the center), but it only offends my anal-retentive sensibilities:

The kit:

_________________
Cheers!
-Karl

'84 GL with 2001/2004 Subaru 2.5L

[Forthwithtx]

Fitment.

These are pretty much self-explanatory. Pictures will switch from left to right, in no particular order, so please don’t get too confused.

I had to wait for the left caliper to come-in to replace the wrong caliper ordered. This took about six weeks due to a shortage nationwide, so work location changes in the photos, as well.

Brake shield holes (3) moved to accommodate radial position of the new caliper (about 1/4 inch) with no trimming of the shield required:

Going together:

These parts of the spindles were a close fit to the caliper body, so I shaved it a bit for insurance:

Re-painted:

_________________
Cheers!
-Karl

'84 GL with 2001/2004 Subaru 2.5L

[Forthwithtx]

Installing brackets, carriers, and calipers:

Don’t do this:

Final fits:

_________________
Cheers!
-Karl

'84 GL with 2001/2004 Subaru 2.5L

[Forthwithtx]

And finally, brake lines:

These are 8" pre-flared lines, available on eBay. I didn't try FLAPS.

Voila! Bleed brakes and on the road!

RESULT: Porsche-level braking ability? No. I would describe the new braking capability as modern appropriate. Before I did this conversion, I once had a sudden impromptu off-road experience into the grassy median of a section of highway because the old brakes weren't going to prevent me from hitting the guy in front of me who was in a panic stop (Dodge Viper in front of him decided to make a sudden 90-degree turn on a wet section of road). I think that now, I could probably stay on the pavement.
_________________
Cheers!
-Karl

'84 GL with 2001/2004 Subaru 2.5L

[fleet_maintenance]

Nice, clean project. Great pictures. Thanks for taking the time to post it up.

[[email protected]]

Wow great job! Thanks for all the pictures.

[newfisher]

Great work! Thanks for documenting your efforts.

[Howesight]

Yes, this is a great thread and has all the pics to explain it all. Are you planning on selling the adaptor piece, bolts, and spacer as a kit? (Syncro owners would only need the adaptor plate and bolts.) I would be up for that. I have never bothered yet to install G-60s on my rig, even though I have several pairs sitting around. I could not find the time to fabricate the adaptor plate, but this summer, some towing is in order, so I have to upgrade to G60's.

The Audi enthusiasts remove the G60's from their S-cars and RS-cars to replace them with Porsche brakes, so, in case of a shortage, one could check over at Motorgeek and Audifans for used G60 calipers and rotors. These calipers are easy to re-build and the rebuild kit is inexpensive.
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'86 Syncro Westy SVX

[icolquhoun]

absolutely great job on this!!!

I am in the process of the same rotor swap but using b5/early b6 single piston calipers.


Do some of your pics show a machined '84 upright as opposed to the '86 upright/spindle?

Those two fly-cut faces where the carrier bolts don't look factory, not that it makes any difference, I was just wondering if you machined early uprights to the later style?

[thasty07]

Yeah, you sell that bracket, let me know! Awesome project!

[Forthwithtx]

[Forthwithtx]

[rubbachicken]

very nicely done, i have the same rotors and calipers, and have had old rotors cut down, i'm taking a different route with the caliper adapters.
although since i started mine, i have seen a different caliper try, that i'm hoping to find some tomorrow.
_________________
lucy our westy

lucy's BIG adventure

meet 'burni'


markswagen {mobile mechanic} san diego area all early VW's cared for.

619 201 0310 or 617 935 4182

[insyncro]

Nicely done.
I would buy a few adapters.