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Re: Rear brake upgrade: 323i to E30 calipers
Posted: Tue May 13, 2014 2:58 pm
by petroscf
As I am going to start rebuilding a set of rear 323i arms and brakes, (Nas's old set), Nas propesed to me that I upgrade into E30 325 calipers, so I am defo going to use this thread a lot!
Are there any other parts from E30 that would fit instead of E21 ones? How about handbrake mechanisms? As they are missing form the set I bought from Nas, I was thinking of ordering E30 instead of E21 ones (if they fit of course)
Dust plates?
Re: Rear brake upgrade: 323i to E30 calipers
Posted: Tue May 13, 2014 3:17 pm
by Jeroen
Don't think that will offer any gains just headaches if it doesn't fit so I'd stick to E21 parts for the rest. Just E30 calipers, pads and hoses.
Re: Rear brake upgrade: 323i to E30 calipers
Posted: Tue May 13, 2014 11:07 pm
by petroscf
Re: Rear brake upgrade: 323i to E30 calipers
Posted: Tue May 27, 2014 5:30 pm
by Sean
Guys,
Are e30 318 & 325 calipers the same? I assume they aren't?
Do i need 318 calpiers or 325?
Thanks
Re: Rear brake upgrade: 323i to E30 calipers
Posted: Tue May 27, 2014 7:47 pm
by Jeroen
Rears are all the same except for 325iX, M3 and touring
Re: Rear brake upgrade: 323i to E30 calipers
Posted: Wed May 28, 2014 9:48 am
by petroscf
Jeroen wrote:Rears are all the same except for 325iX, M3 and touring
In that case, may I guess the whole above thread is for the standard ones?
Would M3 rear calipers fit? (if found of course)
Re: Rear brake upgrade: 323i to E30 calipers
Posted: Wed May 28, 2014 9:53 am
by Jeroen
No M3 calipers do not fit. See bmwfans.info for details.
Re: Rear brake upgrade: 323i to E30 calipers
Posted: Wed May 28, 2014 10:57 am
by Sean
On the hunt for Calipers.

Thanks Jeroen.
Re: Rear brake upgrade: 323i to E30 calipers
Posted: Fri Oct 16, 2020 9:56 pm
by mcjjordan
So im doing e30 rear calipers , need to machine down carriers .
Can anyone confirm what width they need taking down to?
Ive read to different readings!
Re: Rear brake upgrade: 323i to E30 calipers
Posted: Fri Oct 16, 2020 10:22 pm
by Wilmo
Why are you doing this? To get more braking power at the rear? Just install a brake power balancing valve so you are able to maintain the same balance all the time. Standard is a maximum pressure valve installed. Result of that is that for normal braking the balance is there. But since there is a maximum pressure, at full braking the balance shifts forward. When you install a proper dividing valve, balance is always maintained and hence braking force increases. I guess that when installing E30 brakes the piston diameter is slightly different so that as the result of this maximum pressure is somewhat more braking capacity, but that is faking it. I don’t see any point in installing E30 calipers.
Re: Rear brake upgrade: 323i to E30 calipers
Posted: Fri Oct 16, 2020 10:38 pm
by mcjjordan
Im running drums at the moment , got 323 rear end but calipers were shot.
Re: Rear brake upgrade: 323i to E30 calipers
Posted: Sat Oct 17, 2020 12:42 am
by Jeroen
See the opening post for the required bracket thickness.
My experience: E21 rear calipers are only slightly smaller, but there are not many proper pads available in that size. So if you start upgrading the front brakes, even with just better pads and a caliper overhaul, you are lucky to get 10-15% of all brake force to the rear (or I should say: applied to the rear wheels). With E30 calipers there is a bit more bite, but also many more options for proper pads like Ferodo DS2500, that's why I choose for the upgrade combined with my Wilwood 4-pot fronts. And brake balance has improved, now I have 24-28% of the brake force going to the rear which greatly helps total stopping power.
Re: Rear brake upgrade: 323i to E30 calipers
Posted: Sat Oct 17, 2020 12:52 pm
by Wilmo
Yeah, that makes sense, sorry for my blunt approach.
Re: Rear brake upgrade: 323i to E30 calipers
Posted: Sat Oct 17, 2020 12:57 pm
by petroscf
Jeroen wrote: Sat Oct 17, 2020 12:42 am
See the opening post for the required bracket thickness.
Anyone selling such brackets ?
Re: Rear brake upgrade: 323i to E30 calipers
Posted: Sat Oct 17, 2020 8:30 pm
by uwbuurman
Just buy a set of e30 calipers and have the brackets machined.