Re: E28/E36 M3/E34/E32 brake swappability? **Rob

[Jason Lile <jason@xxxxxxxxxxxxxxxxxxxxxxx>]

> 1) So I know that E32 calipers and rotors fit an E28.

right...

> 2) I know that standard E34 calipers and rotors (smaller than E32) fit an
> E28.

Never tried it, so I'll take your word for it... ;)

> 3) I came across a part cross-reference in the BavAuto catalog that shows
> E32 and "540i thru 96" rotors are exactly the same part.

correctamundo!

> 4) My friend told me that his E36 M3 and E34 M5 use the same brakes.

Bzzzzz....  The rotors both measure 315x28mm.  The problem is that the rotor
"hats" are different heights.  The E34 has the deep dish hat like your E28, but
the M3 has a very shallow hat like an E30.  Therefore, the M3 rotor on an E28
spaces the rotor too far from the caliper mounting point.  The caliper would
almost fit behind the rotor ;)  The M3 also has vented rotors that only fit L or
R.  The vanes in the rotor are directional to help with better cooling I
assume.  The M5 only has one rotor for the front L or R.

> 5) The E34 M5 brakes also make a nice upgrade for an E28/E32/E34.

Of course they do!  You can't beat ///M brakes ;)  Unless you have a few grand
burning a whole in your pocket...

> !!! Hmmm... !!!
>
>     I think to myself, "Does this mean that if the E36 and E34 can swap
> brakes, can the nifty E36 M3 Euro Floating Rotor brakes bolt directly onto
> an E28?"

Nope... that hat height kills it.  Also, for everyone else, the E36 and E34
cannot swap brakes so don't start getting any crazy ideas.

> Yep, I know that the E36 M3 and E34 M5 brake disc parts are different
> numbers... since I don't have specs, I might assume the difference is
> something irrelevant (for the scope of this discussion) like metal
> composition or vent size, but bolt pattern, diameter, hat size, etc. may be
> the same and therefore swappable.

If you wanted to get really adventurous and modify the hat size, you might be
able to make something work.  Not your RL/BB 20 minute swap though ;)  Hope that
clears it up a bit.


- --
___________________________________________________________
Jason Lile                               Administrator
Parts Manager                            BMW Parts Digest
Zionsville Autosport
http://www.zionsvilleautosport.com

------------------------------

End of bmw-digest V9 #236
*************************