Firstfives.org

An automatic would have 23.81 mm which is the same as an E28 has.

According to the shop manual for my US 630/633, those cars all had 23.81mm master (auto or manual).

I was all set to go down the path of building some M535 brakes and keeping the stock hydraulics. Those use the thicker 25mm rotor in front, which I would get cross-drilled and cryo-frozen. I had sourced thicker spacers for the caliper halves (from an e23 if I remember correctly) and the NLA square O-rings as well.

But now I may hold off and see how your project works out (keeping the stock MC and just plugging two of the outputs). In theory I think it should work fine. Keep us up to date - looking forward to pics and the road test.

Dave Rutkowski wrote:According to the shop manual for my US 630/633, those cars all had 23.81mm master (auto or manual).

I was all set to go down the path of building some M535 brakes and keeping the stock hydraulics. Those use the thicker 25mm rotor in front, which I would get cross-drilled and cryo-frozen. I had sourced thicker spacers for the caliper halves (from an e23 if I remember correctly) and the NLA square O-rings as well.

But now I may hold off and see how your project works out (keeping the stock MC and just plugging two of the outputs). In theory I think it should work fine. Keep us up to date - looking forward to pics and the road test.

I'll update ofcourse. The front spacers are ready now and I'll test fit them tonight. If they fit well I'll start on the rears. However I don't know when I'll have that done.

In the past I've also looked at the M535 brakes but decided not to because I didn't have a mill available. The spacers would be really easy to make however there is more to gain with newer technology. The stock calipers are very heavy but if you don't want to spend money it might be a good option.

Considering I have a bit more to spend now I see much more potential in the route I took. Adding up the total costs:

-New brembo pads/rotors fronts and rear + hand brake pads
-Used E38 brembo calipers front and rear (plus mc and brake assist)
-New bearings all around
-Sandbasting + new paint of the front and rear suspension parts
-New backing plates for the rear
-Material for the spacers (Made them myself)
-Material for the handbrake filler ring (Made them myself)

In total it will be around a 1000 euros. But everything will be new or as good as new. And in addition quite some enhancements. The current brakes and bearings are due to be replaced anyway so close to half the costs I would have had anyway.

They fit like a glove:

couple of comments:

Are you sure you need rear bearings? They last a long time and changing them can damage the trailing arm if not pulled out evenly.

Also would you be interested in selling blank adapter (with just e12 holes) so I can adapt to Wilwood or other caliper?

Peter Florance wrote:

Fhaas wrote:

Peter Florance wrote: I doubt it. I wonder if any early e23 used ABS?

1981 745i's had ABS, I have one sitting behind the house right now

Frank

Oh Frank, you are going to get me in trouble...

Did they have wheel bearings like e12 or more like e28?

E23s did use conventional wheel bearings like E12's, but they are larger. Seems like the toothed hub is removable too, I think I removed one when I did something or another to one of mine. I might be thinking E28 on the toothed part, but E23s difinitely use standard bearings.

I might also be interested in those adapters if you are going to sell .

Fun to see there is some interest in it but I don't think the market is very big. PM me if you want the drawings for personal use. I'll dig them up somewhere if I have time. I'm usely on the forum at work so it might take a while .

Anyway, I'm kinda set on the E12 rear trailing arms but sometimes it feels like I'm making a mistake. Perhaps the E23 or E28 parts would be much easier. However it would take me some extra time and money which I don't like. In the end I want to upgrade to a E34M5 diff which should be good to hold the power .

DMS wrote:Fun to see there is some interest in it but I don't think the market is very big. PM me if you want the drawings for personal use. I'll dig them up somewhere if I have time. I'm usely on the forum at work so it might take a while .

Anyway, I'm kinda set on the E12 rear trailing arms but sometimes it feels like I'm making a mistake. Perhaps the E23 or E28 parts would be much easier. However it would take me some extra time and money which I don't like. In the end I want to upgrade to a E34M5 diff which should be good to hold the power .

If you don't mind sharing the dwg's, I'll pm you.

I think as long as you use a fairly tall ratio, the side loader should be reasonably strong. 3.07?

Thanks for sharing the drawings!!

Peter Florance wrote:If you don't mind sharing the dwg's, I'll pm you.

I think as long as you use a fairly tall ratio, the side loader should be reasonably strong. 3.07?

Thanks for sharing the drawings!!

Nah I don't mind unless someone is making money out of it. It's where a board is for: try to help each other. I assume you guys will help me out if I have some problems with the car. I've them in AutoCad files. Would that be ok for you?

3.07 would be for a standard 525?

I'm not going to drag race the car which would put the highest load on the drivetrain. However I will track it some day but it's mainly my daily driver. (I feel like I'm going a bit over the top for a daily.)

I've got a guy that has laser and plasma cutters that can import Autocad files; he's made me a nice trigger wheel

3.07 is standard for M535i and 635Csi (E12 based)

Peter Florance wrote:I've got a guy that has laser and plasma cutters that can import Autocad files; he's made me a nice trigger wheel

3.07 is standard for M535i and 635Csi (E12 based)

Cool, make him produce a cam trigger wheel for me .

DMS wrote:

Peter Florance wrote:I've got a guy that has laser and plasma cutters that can import Autocad files; he's made me a nice trigger wheel

3.07 is standard for M535i and 635Csi (E12 based)

Cool, make him produce a cam trigger wheel for me .

Got a drawing? I'll make 2.

Peter Florance wrote:

DMS wrote:

Peter Florance wrote:I've got a guy that has laser and plasma cutters that can import Autocad files; he's made me a nice trigger wheel

3.07 is standard for M535i and 635Csi (E12 based)

Cool, make him produce a cam trigger wheel for me .

Got a drawing? I'll make 2.

In time I will

You all should have e-mail!

Many thanks for the mail!