View Single Post
      09-12-2008, 01:19 PM   #35
synclastica_86
Captain
 
synclastica_86's Avatar
 
Drives: F32 435i, E92 M3, S550
Join Date: Aug 2008
Location: Hong Kong

Posts: 690
iTrader: (0)

Garage List
Quote:
Originally Posted by KenH View Post
"The M3 sedan is quite a bit taller than the coupe, so a CF roof probably wouldn't quite have the effect as it does on the coupe..."

The sedan is 1.4 inches taller than the coupe so therefore a lighter roof higher up would have more of an effect on the sedan's CoG than on the coupe.
The glued-on CF roof adds torsional rigidity to the bodyshell in comparison to a bodyshell with just the cross strut (and no roof or one not glued on).
This is why manufacturers (starting with FIAT on the 128 in about 1970) glue in the windshields these days. Previously they used to sit in a piece of rubber and "float" which added nothing to the torsional rigidity.
Wait... I don't really get it. Why does gluing on a CF roof help add torsional rigidity? A steel roof doesn't float too, would that give the same strength as gluing a CF roof on?
__________________

Current: BMW F32 435iA, M-Sports; BMW E92 M3, M-DCT; Mercedes Benz W221 S550 4matic, AMG Sports package
Retired: BMW E93 323iA; BMW E85 Z4 3.0i, SMG; Lexus IS 250 AWD; Lexus GX 470; Mercedes Benz W203 C230 Sportscoupe
synclastica_86 is offline   Hong Kong
0
Reply With Quote