Fitting e30 rear calipers to e21 trailing arms

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Jason_323i
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Fitting e30 rear calipers to e21 trailing arms

Post by Jason_323i »

I was sorting out a set of e21 323i trailing arms to sell and I had as I had a set of e30 rear calipers sitting around I thought I would fit them, as you can see the e21 and e30 calipers are pretty close, the e30 calipers are a more modern design have a slightly larger piston and a far superior brake pad choice.

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To modify the e30 calipers you need to drill the m10 mounting holes out to a 10mm hole on the caliper carrier, as on the e21 trailing the calipers bolt to the arm but on the e30 the arm bolts to the caliper. Also on the e30 caliper carrier there is a raised section between the mounting holes need to be ground down. The bits to be modified are shown below.

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Modified caliper carrier looks like this

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Next just stick the caliper back together

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Then I cut down some drive shaft bolts as the shoulder on the bolt was spot for length

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Then just a case of bolting the caliper up

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The e30 brake hole fits but is about a 1" to long so a e30 stainless flex would be better (easier to bend).

J


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nas80
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Re: Fitting e30 rear calipers to e21 trailing arms

Post by nas80 »

Nice work.

Will defo do this when my calipers die!
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costask2
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Re: Fitting e30 rear calipers to e21 trailing arms

Post by costask2 »

Hi Jason,

realy intresting upgrade.. I just want to ask if you use the e21 disks or the e30?

regards Costas
-----BMW don´t follow the technology, BMW leads it-----

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Jason_323i
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Re: Fitting e30 rear calipers to e21 trailing arms

Post by Jason_323i »

The e21 disks and e30 disks are the same part

Jason
BMW e21 race car supercharged s14 cage and fabrication by www.chizfab.com
Z3M Coupe
2.8 Z3 Coupe
Caterham Supersport
Clio 172 Cup factory race car(50%)
Ferrari 348 Challenge track car
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costask2
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My E21(s): ´82 315 powered by s14
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Re: Fitting e30 rear calipers to e21 trailing arms

Post by costask2 »

Jason_323i wrote:The e21 disks and e30 disks are the same part

Jason

OK, didn´t know that.. thanks.. I´m doing a e21 s14 upgrade at the moment and I´m checking out the best brake options.. I´ll open a thread soon with pics etc at the owners gallery...
-----BMW don´t follow the technology, BMW leads it-----

BMW e21 S14
BMW e46 325ti
BMW e38 740iL
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