E21 front brake upgrades

1982 323i
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E21 front brake upgrades

Post by 1982 323i »

After purchasing Anders´s wonderfull B6 replica, i started thinking about a brake upgrade. I remembered a post maybe on another forum regarding that topic, but i can´t seem to find it.

I got a volvo 240 4-piston caliper that fit´s nicely on the front strut mounting points but a little offset(a washer can fix that) but what brake disc can i use? The 323i 255 mm ventilated disc is not near big enough(great! a larger disc) so who has been down this road and found out what disc to use with the right size and offset?


1972 2002 Tii
1973 2002
1978 320/6
1985 535i
1987 M3
1986 M3
1981 Alpina B7 turbo
1992 316i
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Post by rasb1 »

Hehe, A Volvo part has nothing to do on a bmw!!!! It should be possible with E36 M3 calipers I have been told :idea:
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Jeroen
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Post by Jeroen »

Nope, the calipers (Girling items just like on many E21's) are good. But I believe they were used with the stock vented discs (rotors)?

The E21 vented discs are 255mm, the E30 325i for example has 260mm. Maybe it fits, dunno. Otherwise... there are some more serious big brake kits like from Tar-Ox... but I dunno if they're still available. And most times they require 15 or even 16" wheels.
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Madhatter
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Post by Madhatter »

It doesnt fit, the offset is incorrect (the E21 is much larger).

There was a discussion on bimmerforums recently if you want to have a read through it. http://forums.bimmerforums.com/forum/sh ... p?t=393182

As jeroen said, girling calipers from a volvo were the go, you use the stock vented 323i rotor though. The caliper was designed for a larger rotor so you end up with some overhang, most people notch the holes to position the caliper correctly.
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1982 323i
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Post by 1982 323i »

rasb1 wrote:Hehe, A Volvo part has nothing to do on a bmw!!!! It should be possible with E36 M3 calipers I have been told :idea:
Maybe, but these calipers are the single piston sliding type. A setback compared to even the stock twin pot calipers in my view. But if you´re interested i have a set of E36 M3 calipers lying about!

Madhatter, i just read a writeup concerning exactly that. That may be a good route if i can find some serious 323i disc´s.

Any ideas?
1972 2002 Tii
1973 2002
1978 320/6
1985 535i
1987 M3
1986 M3
1981 Alpina B7 turbo
1992 316i
2001 530d touring
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Madhatter
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Post by Madhatter »

what do you mean serious 323i discs? :)

All 323i rotors are 255mm, you can get aftermarket options in a choice of pretty much anything, cross drilled, slotted, weird patterns, etc.

I provided the dimensions of the hat in that link, pretty much any rotor/hub that matches those dimensions would fit.
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Post by E21Dane »

I recently looked into it myself...

Like rasb1 I wasn't feeling too keen on bolting Volvo parts to my E21, so I shopped about a bit.

Jeroen mentions Tar-Ox. I can confirm that these are still available. :P Absolutely awesome stuff!! BUT, their big-brake-conversion (requires 15 inch) is not exactly cheap... Here in Denmark I would have had to pay € 2400... :shock: :shock:
Plus the expens of having to buy a new windshield every time I had hit the brakes hard, because everything in the cabine (incl. myself) would go flying onto the bonnet... :twisted: hehe....

But Tar-Ox also still produce discs for the standard calipers, which would probably have been my choice if I had been able to keep the car...
Senior Ras, check out this site from Denmark...

http://www.racetech.dk/

The Tar-Ox Sport Japan discs are serious stuff... :twisted:
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Anders.

Previously owned E21s:
'82 BMW 323i Alpina B6 3,5 rep.
'82 BMW 323i Edition S

Currently own:
'72 BMW 2002 - Agavegrün
'73 BMW 2002 - Veronarot
'74 BMW 3.0S - Polarissilber
'85 BMW 325e - Karminrot
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Post by ichiwan2 »

My calipers, off a 323i, were made by ATE, I think. Any other brands are/were standard for the e21?

Checked with Partsbin.com and one of the choices was a 2pot Girling??
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Post by 1982 323i »

OK i think will choose one of either routes, both including the volvo 4-piston calipers i got for free.

Option 1: Change the mounting points for the calipers, in order to retain the stock disc size. Of course with uprated disc´s and pads.

Option 2: install a disc with the optimum size for the calipers(Around 270 mm) This being made with a 2-piece disc and a bespoke aluminum center section.
1972 2002 Tii
1973 2002
1978 320/6
1985 535i
1987 M3
1986 M3
1981 Alpina B7 turbo
1992 316i
2001 530d touring
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Post by Jason_323i »

Hi

If you have the rght calipes they bolt right up thee wee two types on the Volvo.

On my car I need a 1mm spacer to center them then i just boleted them on alonf wih an e12 master cylinder and an extra set of front e21 hard brake lines and 2 sets of S/S flex lines (the volvo calipershave twin inlets)

The pads set about 3mm over the disks (but so what) but yoy can slot the calpers to fit them.

Also you can upgrade the rear with a set of e30 rear calipers on the 323i but yu need to machen them to ft as the bot from the otehr side on the e21, also you need custom brake lines.

On drum bakes you can use a set of golf Mk3 calipers and e30 rear disks, these kits are sold in the US with a few spacers and a modifesd handbrake cable so you need to work that bit out for your self.

Jason
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Post by jrcook320 »

I have done this conversion. It was fairly straight forward, but the calipers I bought overhung the rotors by exactly 7mm, not the 3mm that I often see posted. I had to slot them to get them down to 1mm overhang (I used a carbide bit and die grinder), and also used 1.5mm washers to center the calipers on the rotor. I actually went to the hardware store with calipers (measuring calipers) and measured washers to make sure I had all the same thickness (washers tolerances aren't too tight). I bought my calipers brand new for about $60 USD each at http://fcpgroton.com/volvo240brake.htm, but prices have gone up since then. I bought part #5002028X and 5002029X, a hardware kit, and metal master pads.

First, trim the backing plate so the calipers will fit:
Image

Unslotted caliper with 7mm overhang:

Image


Slotted holes:

Image


Calipers mounted after slotting the holes, only 1mm overhang now:

Image

This put the caliper so far back that i had to grind a little material off of the front strut where the caliper mounting bolt holes are for brake pad clearance. BTW, I have the clips installed backwards in the pic, they should be over the metal backing plate on the pads.

I decided to use the E21 master cylinder for now because I already had a new one. I used a metric brake "T", bought mine from a VW supplier, but its the exact same "T" that is used in the rear brake circuit. Also, If you are doing a big front brake swap and a rear disk conversion, you should consider an adjustable proportioning valve. I used a Wilwood valve (bought from summitracing.com) pretty cheap, and looks good too. I had to use a combination of metic and SAE bubble and inverted bubble flares to adapt it into the system. Summit's wilwood valve is SAE, but I have read that Ireland Engineering sells a metric version.

Front brake line routing. I bought brake metric brake lines at Autozone for a few bucks (along with their rent-a-tool cutter and flare kit) and bent my lines by hand. Despite the single circuit split to 2, the brake pedal feel isn't too soft for my tastes. An E12 cylinder is the best way to go though.

Image

Image


I mounted the proportioning valve on the factory air filter mount, a great spot for easy adjustment. Or you can run the line up into the passenger compartment for in car adjustment.

Image


I removed and bypassed the stock proportioning valve with a female-female brake line connector:

Image


Rear disks are stock E21 323i.

Image

Rear disks offer several advantages over drums. They fade less, the stock 323i disks offer more stopping power to compliment bigger front brakes, you can upgrade to e30 calipers which offer even more stopping power, and they don't require adjustment (those adjusting bolt heads always seem to get stripped!)
Last edited by jrcook320 on Sat Feb 03, 2007 4:47 am, edited 1 time in total.
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Post by Jeroen »

Excellent... thanks mate!

And dam... even there the car looks brilliant :wink:
Regards/groeten, Jeroen
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Post by E21Dane »

Awesome pics mate and some seriously beautiful work you've done there...

Looks really pro!! :P

Looks like you've got all you need to know right here Senior Ras... :wink:
Good luck with the project - hope it turns out as neat as this one...
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BMW-regards,
Anders.

Previously owned E21s:
'82 BMW 323i Alpina B6 3,5 rep.
'82 BMW 323i Edition S

Currently own:
'72 BMW 2002 - Agavegrün
'73 BMW 2002 - Veronarot
'74 BMW 3.0S - Polarissilber
'85 BMW 325e - Karminrot
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Post by jrcook320 »

Thanks guys. Now all I need is 270mm rotors so I can push my calipers all the way out. :)
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