BMW 728i Brembos

[afterburner]

I searched the forum but found nothing definitive. Has anyone used the front Brembo calipers that come with several BMWs like the 728i for example on a B3/4 platform car?

I got hold of a set but I'll be able to test fit them to my car not before the weekend, so just looking for some heads up. The idea is to use them with 324x28mm discs from a Ford Focus RS with 4x108 bolt pattern, as I don't want to change my hubs/wheels (like the way the original competition 16" look and feel).

I guess I will need an adaptor with 4 holes because of the different PCD of the original and Brembo calipers. If no one knows - then when the weekend comes I will post my results.

[gripper]

http://audifans.net/ftopict-31997-.html

[afterburner]

Cool! Those adapters look very easy to make! Thanks! That's reassuring!

[s2_wot]

Very tight fit under 16" rims. The mounting holes are not symmetrical as you would expect. Remind me tomorrow I'll take some photos of my brackets for you.

[s2_wot]

Bracket Drawing in the attached document is not perfect. The calipers are not symmetrical. If you take any more accurate measurements of the calipers please show them here.

Photos to give you an idea of the mounting bracket

If you're working with less than 310mm diameter disc and looking for a perfect 90 degree trailing position then the caliper and the hub will collide.









I had these samples made in 3 parts to make them cheaply.

[afterburner]

Today I got the Ford Focus RS discs, I hope to have results in the coming weeks

[afterburner]

Had some other things on the to-do list, but managed to get the adapters ready. Will test fit them and see how things come into place.

I'm trying to fit them under the original Competition 16" rims, which involves using 25 mm spacers, so I decided to use rear B4 hubs on the front, which have smaller offset and bring the whole wheel set-up inwards, which compensates for the big spacer resulting in a ~15 mm spacer equivalent (the difference between hubs is ~10 mm).

I also plan on using my front hubs on the rear which will give me around 10 mm more offset in the back without using spacers, which is perfect. I only have to make some 10 mm spacers for the rear callipers to bring them out so they stay aligned with the new position of hubs/discs.

[afterburner]

So, the setup works great for now, I did what I planned and switched hubs front/back, so the 25mm spacers on front that were there for clearance act more like 15mm spacers, because of the smaller offset hubs and I didn't use any spacers on the rear to widen the track.

Here's a CAD drawing of the adapters, they position the calipers perfectly on the Focus RS discs. The only other thing needed are cylindrical spacers to correct the offset of the caliper in respect to the disc, which should be approximately 11mm for standard hubs (in my case it was 11 mm + the difference in offset between front/rear hubs)

Edit: The file is a SolidWorks drawing of the adapters, they are made from 10mm thick sheet metal

[afterburner]

Here they are

[gripper]

Great work ! Thanks for sharing
Unfortunately I cannot open the file with the CAD drawing

Can anyone convert it for me ?

[afterburner]

I don't have access to SolidWorks anymore, but tomorrow will try and find a screen shot of the drawing with the dimensions on it on my computer at work and will post it

[@ndy]

I'll see if I can open the cad file tomorrow and ill put it in different formats. This is a great guide, will look into doing this myself I think.

[afterburner]

I'll see if I can open the cad file tomorrow and ill put it in different formats. This is a great guide, will look into doing this myself I think.

Very nice!

BTW Guys, keep in mind that depending on the rims probably not all 16" will fit with 25mm spacers, some may need more, some may need less It's pretty damn close with 16" rims, but it's perfect for 17" +.

But the nicest thing about this whole deal is widening the rear track of an avant/sedan without using any spacers - just put front hubs on the back and some small cylindrical spacers on the calipers, makes removing tires a lot easier without having any spacers

[afterburner]

Here's a screenshot with the dimensions

EDIT: The diameter around the 12mm holes on the right side of the image is 25mm (the one that on the left side is 28mm), it's missing from the image.

[@ndy]

Gents,

Please find attached a zipped folder containing the model file as an .stl and .x_t

hope this helps.

Andy