Metrix Motorsports is offering a rear disc conversion kit for the e21 using the existing drum brake rear trailing arms. Bit pricey for me at the moment and unsure of the quality and pita factor. Have a look:
http://estore.websitepros.com/1397118/Detail.bok?no=91

What's a 323i rr disc brake setup worth these days?

The 323i trailing arms usually go for $500-$600. A shocking price for both that and the MM kit considering the simplicity of making a caliper mount bracket.

The 323i trailing arms usually go for $500-$600. A shocking price for both that and the MM kit considering the simplicity of making a caliper mount bracket.

I'm really surprised that someone on here hasn't tried to make their own setup yet. I'd consider it if I had some means to do it with, but I lack pretty much everything anymore.
Jake

I'm working on it. And it will be much better than MM.

I'm working on it. And it will be much better than MM.
if you can make it cheaper and more easily accomplished, it'd be great. good luck!
Jake

I'm working on it. And it will be much better than MM.Look forward to seeing more on that project:)

I'm working on it. And it will be much better than MM.

make enough for the right price and you might make some money cuz id sure be interested

if anyone is interested i have a set for sale, real 323 arms with 9/10 poly bushings
new brake calipers,(rebuilt) new rotors and brake pads originally purchased for 500+150 shipping and nothing worked, i restored the arms, coated them with POR15, Sealer and hammarcoat, bought rebuilt new calipers/bushings/rotors/and pads, and braided lines. im willing to let go for 500, OBO. I dont have my e21 as most of you know so they're no good to me. make me an offer i cant refuse and we can work something out.

I'm working on it. And it will be much better than MM.

I've been looking at this as well. Seems like you could do it with 325i parts and one bracket. Where is that restrictor or whatever to reduce the brake fluid flow to the rear drums?

I've been looking at this as well. Seems like you could do it with 325i parts and one bracket. Where is that restrictor or whatever to reduce the brake fluid flow to the rear drums?

I think its in the T fitting up by the rear subframe on the driver's side. Part number 34331163566 on realOEM. Someone please correct me if I'm wrong.

I think its in the T fitting up by the rear subframe on the driver's side. Part number 34331163566 on realOEM. Someone please correct me if I'm wrong.

You are wrong. Thats nothing but a regular T.

There is a "pressure reducing valve" on the firewall down low where you almost can't see it. One only has to replace it with an adjustable type (wilwood or other) proportioning valve.

You are wrong. Thats nothing but a regular T.

There is a "pressure reducing valve" on the firewall down low where you almost can't see it. One only has to replace it with an adjustable type (wilwood or other) proportioning valve.

ah, shucks! Nice to know though. :)

It sounds like most of you here don't really care much for a rr disc brake setup if you can't get it dirt cheap. I think if I had a 320i, stock drums would prove to be fine enough the way it is.

But, what if you've done an M20 conversion? WOuld having rr disc brakes be something that's a necessary upgrade ? I don't know...I've owned 320i and 323i, and I'm not sure what value the rr disc brakes offer, except that w/ discs, you don't ever have to keep adjusting the brake shoe clickers.

I don't think it's "necessary" if you have a six cylinder. The cars are so light that the standard brakes should work fine. I just want to design the bracket so that others can go snag E30 rear discs and calipers and have a bolt on type setup.

HOw are you thinking about doing the bracket ?

Laser cut a flat blank ? Or CNC mill it?

btw...last I checked, a laser cutter can only do up to 5/16" thick.

When one of you guys get the setup working, I'd be very interested.

My bracket is going to encircle the rear axle and use all 4 bolt holes back there. Not sure if its neccesary, but it'll be 10 times stronger than the MM setup. Plus it'll hold the backing plate for the drum parking brakes. Thats the trouble with using e30 parts, the drum brake is more work to make than the entire rest of the system. Its the best solution though (in my opinion).

My bracket is going to encircle the rear axle and use all 4 bolt holes back there. Not sure if its neccesary, but it'll be 10 times stronger than the MM setup. Plus it'll hold the backing plate for the drum parking brakes. Thats the trouble with using e30 parts, the drum brake is more work to make than the entire rest of the system. Its the best solution though (in my opinion).

Layne, I've been tossing around the idea of using a caliper similar to this guys:
http://www.britishv8.org/MG/GaryWalker.htm <--- Nice MG by the way!!!
http://www.britishv8.org/MG/GaryWalker/GaryWalker-W.jpg
You just need one. And the mount would be a billet block attached to the same plate. Could even use the stock cables off the e-brake on the car already. You could use both. I was thinking one would keep costs down. Do you have access to a waterjet?

Where is that restrictor or whatever to reduce the brake fluid flow to the rear drums?

It's the blue cylinder in the photo:
http://i25.photobucket.com/albums/c58/jrcook320/Volvo%20Brakes/04-20-04011.jpg

If you're swapping to rear disks, you need to make sure the rears don't lock up before the fronts do in the rain. If they do you need to swap to the 323i proportioning valve or get a wilwood adjustable proportioning valve, like this:

http://i25.photobucket.com/albums/c58/jrcook320/Volvo%20Brakes/04-20-04016.jpg

It's the blue cylinder in the photo:
http://i25.photobucket.com/albums/c58/jrcook320/Volvo%20Brakes/04-20-04011.jpg

If you're swapping to rear disks, you need to make sure the rears don't lock up before the fronts do in the rain. If they do you need to swap to the 323i proportioning valve or get a wilwood adjustable proportioning valve, like this:

http://i25.photobucket.com/albums/c58/jrcook320/Volvo%20Brakes/04-20-04016.jpg

show off.

Nick, I had thought about that. I saw a commercially available MGB rear disk conversion that had a similar setup that was actually cleaner and better looking in my opinion. The lever also pulled a different way. But I really liked the internal shoes for myself. Wilwood is making a caliper now with a parking brake in it, or you could use those ones like MM is using. I don't care for 1 pistons calipers myself.

JR, is that your car (I don't see a turbo)? Is there any problem finding metric hard lines and fittings?

that's my car before the turbo.

I have no problem finding fittings, autozone sells bubble flared green plastic coated metric lines in various lengths from 12" to 48" with either jap style metric or euro style metric fittings.

To install the prop valve I had to re-flare the lines to use SAE fittings at the valve. I think the lines on the rear brake circuit went as follows: metric bubble flare at MC to SAE inverse bubble flare at prop valve inlet, SAE inverse bubble flare at prop valve outlet to metric inverse bubble flare at female union, and I shortened the stock rear line with an inverse bubble flare for the female union to bypass the stock prop valve.

If you don't want to re-flare the brake lines you can buy the wilwood prop valve from ireland engineering. They just re-tap it so you can use all metric fittings.

It sounds like most of you here don't really care much for a rr disc brake setup if you can't get it dirt cheap. I think if I had a 320i, stock drums would prove to be fine enough the way it is.
the main reason that I would want rear disc isn't for the added force, but for the greater number of performance pads available. there is only one kind of shoe for the drums that is track rated, whereas with the e30 calipers (which one could swap onto 323i arms) the variety is wide, and the prices are quite a bit cheaper.
Jake

If I recall, Porterfield makes shoes for the rear. I don't know why you'd need more options than that.

JR, that sounds like a huge hassle. Wilwood offers a SAE and metric version, no idea whether its jap or euro. I didn't even know there was a difference.

My car came with a "custom" rear disc conversion using 95 corvette rear calipers and some shaved down vented rotors (just the inside face), with adapters and ss lines. I subsequently explained to my cousin (prev owner) that this custom set-up he bought from some unseedy character (for $1k) was that the rear surface area was LARGER than the stock fronts, and thats why the car kept sliding out anytime he jammed the brakes. that and there were no e-brake, and the calipers gouged the inside of the stock rear wheels!!! $200 later and i had new drums, hardware, shoes and rebuilt rear arms!!

A thousand bucks for that crap setup?!? Wow.

I can't believe he did that and nothing to the fronts.

meh on rear brakes, some decent rotors and pads is i'll i'm running. going to run a BBK on the front soon. the car pulls up well with the rear disc's, if your going to be running a bit of fast track work i would think about getting the disc rear end

I don't care for 1 pistons calipers myself.

You don't care for 1 piston e-brake calipers? Or you don't like the thought of putting E30 rear brakes on the car? I was just using the E30 rear brakes as low cost option.

I was talking about MM's 1 piston setup. Any 1 piston though really, the whole idea is just silly. I'll be using wilwood 2 pistons for the back.

hey layne ever get anywhere on that bracket?