Brake upgrade e32/e34 for e24

[85MSteinway]

I'm in the process of putting e32 front rotor/caliper and e34 rear rotor/caliper and e32 M/C for an e24 I bought for my wife. Parts are getting hard to find. I've had to order from 3 different vendors so far to get all the pieces I need for this job. I've meticulously gone through a lot of brake upgrade threads here and on other boards and pretty sure I'm ready to tackle this job.

I'm using these as reference:

http://bigcoupe.com/phpBB2/viewtopic.php?t=2137&
https://www.bimmerforums.com/forum/show ... pgrade-oem
http://www.bmwe34.net/E34main/Upgrade/Data/mbrake.pdf

The problem I'm having is on the front rotors. I havn't ordered the fronts yet because everything I have read said front rotor size for e32 is 302mmx28mm with single 60mm piston. These have been hard for me to source, and I do not have a core so they are expensive as well. The only place I can find that has e32 front rotors for sale is ECS Tuning and for e32/e34 front rotors they list the size as 308x28mm. I can't determine if this is just a rounding error of some sort, or just measuring from different parts of the rotor (total size vs usable area perhaps???)

Am I stressing over nothing and I should just order what ECS Tuning is listing as 308mm? Or is ECS listing the wrong part? These are the rotors I'm looking at: https://www.ecstuning.com/b-brembo-part ... 6756090kt/

It isn't just the Brembo rotors they list at 308mm either, they have the ATE, Genuine BMW, Meyle. These are all blank rotors. No slots/drills etc. The "performance" rotors they list for e34 do not have sizes listed for them. I don't want to buy drilled/slotted rotors unless that is all that will fit.

Can anyone shed some light on this discrepancy?

[86_6series]

302 mm is the diameter.

https://www.turnermotorsport.com/p-1972 ... -bmw-part/

https://www.eeuroparts.com/Parts/42186/ ... 116756090/

https://www.turnermotorsport.com/p-1972 ... -bmw-part/

[85MSteinway]

Thanks for those links. Much appreciated. I know turner didn’t have the calipers in stock and I didn’t check their rotors. But the other sources will be a good for parts going forward. Not sure why ECS is saying 308. Thanks again

[cc_in_cc]

I did a similar upgrade earlier this year and found everything I needed at rockauto.com

[85MSteinway]

I spoke with ECS and they said it was an error and now their website shows the rotors as 302mm. Oh well, confusing, but I now have all my parts on order.

[ternandofoledo]

Hey, sorry to 'hijack' your post, but I'm doing a similar job in an E12 car - yours was e12 based or e28?

I'm stuck in the center hub part, where the e12 structure uses the rotkr behind the hub, and the e34 is the modern way, with it in the front.

Any ideas on how to manage this? :X

Thanks a lot!

[85MSteinway]

Hey, sorry to 'hijack' your post, but I'm doing a similar job in an E12 car - yours was e12 based or e28?

I'm stuck in the center hub part, where the e12 structure uses the rotkr behind the hub, and the e34 is the modern way, with it in the front.

Any ideas on how to manage this? :X

Thanks a lot!

e24. sorry, no experience with e12.