B8/B8.5 Rear BBK

[xRenesis]

Been sitting on this one longer than intended, but with Vosh no longer an option and people reaching out to me, I'll be posting my own version of a rear BBK bracket similar to what I did for the B7 chassis.

Files will be made public once I can somewhat verify fitment and make time for, but I already have a decent start. The goal is to accommodate stock 330mm (clearance issues) and 356mm rotors. This post will be updated as things develop.

Update
10/06/24 - To a confident level in fitment
10/15/24 - 350mm test fit sent out
2/28/25 - 356mm proto installed
3/22/25 - 356mm updates made, test fit, plating request, harness test
4/17/25 - add 356 dxf




Install
Bracket is universal between sides.
A ~4mm spacer is needed on the Touareg calipers.


356mm Rotor
356mm Rotors (S6/S7)
Q7/Cayenne/Touareg Calipers 7L6615423L & 7L6615424L
2012-2016 Tesla Model S Parking Brake 1021250-00-F & 1021250-00-G (rotate motors/connectors)
Rear Brake Lines (B7 RS4 Front Lines)
2x M12-1.50 x 60 Flange Bolts (or preference, stock caliper bolts)
2x M12-1.50 x 40 Flange Bolts (or preference, stock caliper bolts)
Provided
2x Brackets
2x Tesla Parking Brake connector/pigtail
4x M14-1.50 x 35 Flange Bolts (or preference)
4x M10-1.50 x 80 Flange Bolts (or preference)
8x M6-1.00 x 20 Flange Bolts (or preference)
4x M14 x ~4mm Thick Washer (McMaster 98025A034)


STEP FILES
XTG-B8-RBBK-356

DXF FILES
XTG-B8-RBBK-356

PDF
XTG-B8-RBBK-356

[a4darkness]

Tracking

[xRenesis]

Pretty good progress, doing what is hopefully the final 3d print for a 330 rotor. Other sizes would be pretty easy after that.

[xRenesis]

Sent of couple test fit brackets to A5/S5 owners just to double check. If anyone has a specific size rotor they want to run, assuming same offset, let me know.

[xRenesis]

Going to send out one *last* test fit to another member, but I'm at a confident level for the Q5. First post updated if anyone had access to steel/3d print and wanted to test the setup on stock 330mm rotors. Other rotor sizes would be 2 dimension adjustments.

[Frankito71]

Nice

[Silence]

On this note, does anyone have a true rear BBK? DId Brembo ever make?

[Dr.B6Banter]

Good to see progress on the B8 platform. The bracket has been working well on my B6 and has been though 2 summers full of track sessions without issue.

On the B6 platform, the front 6 piston Brembo calipers bolted right up to the knuckle but I know this is not the case for the B8 and an adapter is required. That may be an opportunity to look into down the road unless adapters are already available for it that I'm not aware of.

[uponone nogaro]

Any up dates for the b8.5 s4, I was looking at getting vosh mod style Rear BBK kit, thanks in advance for any updates

[xRenesis]

There are some front BBK options floating around. As far as the rear goes, I have a 356mm option sent out for fitment. Tentatively spring time is my goal to have everything sorted and polished, parts needed, harness, rotor options, etc.

[uponone nogaro]

Cool be i will be interesting in the rear 356 BBK

[xRenesis]

I just about have everything I need to test fit this weekend, prototype plates in hand.

The way I would likely handle this, with other's interest, would be unplated brackets + bolts for $175 shipped.
Plating options I would need to dig into, but that would let people powder coat or do whatever.
Pigtail for the parking brake I still need to dig into as well.

[xRenesis]

Installed a personal/prototype 356mm version today. There are two dimensions I'll clean up as a finished version, but for personal use, they are close enough for use.

[J.Costello]

When do you think they will be available, and what are the 356mm rotors from a C7?

[xRenesis]

I could have 5 sets or so cut by the end of the month. Corrections were pretty quick.

Rotors are C7 S6/S7, D4 S8 (4H0615601P4KT). With the way I have it modeled/setup, I can make for the 350mm quickly. I also want to see about taking the front 345mm and putting them on the back.

[Frankito71]

By the way, I have forgotten to message you. The bracket you sent me fits perfectly on my SQ5. Will you be selling the bracket once you finalize them?

[xRenesis]

That's the current plan. Slowly been piecing together what is needed. I have connectors ordered to make a connection harness between stock and the tesla, so no splicing. Bolts I could order in qty, would be zinc flake/ecoguard, probably re-use the M12s that hold the stock caliper on. Then it is just the bracket I can get made, which will probably stay unplated. No fault to Voshmod, but I'm not trying to do everything in house either.

Calipers and rotors would be on the buyer. Rebuilding if needed would be on the buyer.

[J.Costello]

Put me down for a set

[uponone nogaro]

Put me down for 365 rear bbk bracket harness set up thank you

[B6ayfour]

what kind of wheel specs would you need to clear a set of the 365s on a b8.5 S4?

[xRenesis]

It looks like a 17.5" barrel dia, I don't have a model of the Tesla parking brake, but outside dimension is about the same. 19s should still clear.

[J.Costello]

I want a set when they’re available

[xRenesis]

I'll have 5 bracket sets with hardware done this weekend, just need to tap the holes. I need to test the harness this weekend.

[J.Costello]

What material will they be made of?

[xRenesis]

5/16 A36, a little overkill but takes into account the Q5 weight and trailering.

[J.Costello]

OK, will have to get them coated then

[xRenesis]

I have 1 place in town that does plating and they could have them done in a few days. Correct harness parts ordered.

Should be able to have everything ship around next Friday for anyone who's ready for the first few, pending any issues.

[Frankito71]

Let me know when you have one available for the 350mm SQ5, i will take it. Also, what brake line will you be running?

[xRenesis]

You'd have to clarify what the 350mm rotors are from, I know I sent out a 350mm test but just to be sure on spacing, or maybe be fine using what I have for the 356m and giving up 3mm of pad.

Lines are B7 RS4 fronts.

[Frankito71]

You'd have to clarify what the 350mm rotors are from, I know I sent out a 350mm test but just to be sure on spacing, or maybe be fine using what I have for the 356m and giving up 3mm of pad.

Lines are B7 RS4 fronts.

Yeah originally the S6/7RS7 calipers are for the 356mm rotors but 034 makes them 350mm so the pads cover the rotors a lot better.

[pavant]

Looking for a set B8 S4

- - - Updated - - -

Looking for a set B8 S4

[xRenesis]

Just waiting on the 5 sets I have right now to get done at plating. Once those are paid for/shipped, I'll get more sets going, probably about 2 weeks from now.

[hodan]

Jumping in on this thread as I’d be interested. I’m doing all 4 corners this summer.

[xRenesis]

*pricing update*

First 5 sets are all plated and ready to ship. 365 will have to be a later date and I would imagine it working with the ECS 350 if they took after the 356.

[MetalMan]

Ugh, I was feeling set with my current C7 S6 356mm rear setup (on B8.0 A4). I'll have to look at pricing on calipers and parking brake. Also curious how it would align with my front setup of 4M Q7 calipers + 380mm SQ5 rotors.

[xRenesis]

Have 3x 356 sets left. Plan to make 5x 365 sets next week.

[xRenesis]

Just in case I'm losing my mind, the 365 in question is the RS5 front 365x34? That won't naturally fit in the Touareg/Cayenne rear caliper, which is 30.9mm between the pad nubs.

[uponone nogaro]

I’m looking at the 365 brackets with harness

[xRenesis]

Added dxf file for anyone that wants to get them cut locally or have their own shop do it

I have 5 more sets cut, but original price has to be updated. Apparently the software we were using to quote employees hadn't been updated in a good while.