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Discussion Starter #1
Hey everyone,

I was wondering whether anyone can tell me if the roof on the m5 is a load bearing piece of the body or whether it is simply an aluminum skin like the e46 m3s. Im essentially asking whether the roof piece is removable. (which it is on the e46 m3) I would be very grateful if anyone could answer this question for me. Thanks in advance!

Ernie
 

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Yes it improves the properties. and reduces weight where weight should'nt be.

at least as long youre not rolling the car.... - and iam not planning to to that :-.)

The swap is being done exactly as the OE M3 CSL roof is done by BMW.
 

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Interesting :)
 

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540is said:
its "removable" - still welded though. I'am replacing mine with a CF roof
anyone instrested? - sign up !
This is interesting... how does it effect the structure? How does the Cf get bonded to the rest of the body? and lastly, how much weight savings?
Mike
 

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nagisoftware said:
How much weight can you possibly save if its already aluminium?
would it be worth it?
Is the roof aluminum? BMW seemed to make a big deal over the cf roof on the csl m3, so i thought it was a pretty decent chunk of weight. Not that i'd do this myself.
Mike
 

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I remember seeing a show where they were testing the Mitsubishi EVO MR with the aluminum roof and the weight saving over steel was around 12 pounds. The show then taped down thick rubber to simulate the weight of the steel on the roof and compared the handling differnce on a track. The professional driver said he could feel the difference, so maybe it's worth it.

John
 

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Not sure if it was the same article, but i recently read something similar about the evo. THe CF roof vs Al (which i think is on the evo rs) lowered the cars center of gravity by like 2.75 inches!
Mike

jeeperjohn said:
I remember seeing a show where they were testing the Mitsubishi EVO MR with the aluminum roof and the weight saving over steel was around 12 pounds. The show then taped down thick rubber to simulate the weight of the steel on the roof and compared the handling differnce on a track. The professional driver said he could feel the difference, so maybe it's worth it.

John
 

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Discussion Starter #12 (Edited)
hey guys,
first, the CF roof represents a very significant weight reduction: I know on the e46 m3 its almost a 100 pound difference. however, most of that weight difference comes from the fact that the CF roof deletes the sunroof. regardless, it makes a VERY big difference if you are into performance driving.

secondly, the roof panel on the e46's is non-load bearing and is not welded in. so if you replace it with a CF roof you dont lose any rigidity and you only have to cut through the seal holding the aluminum piece in and reseal the new CF roof piece; fairly straightforward.

if the roof on the e39 is welded in I wont be replacing mine, i just figured if it was an easy swap i would consider it. oh well, keep me posted on the progress 540is. I might still be interested.

ernie
 
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