QUOTE(r_towle @ Jan 12 2004, 06:34 PM)
I seem to recall a thread mentioning that the 911 front cross member that atttaches to the rear of the A-arms and supports the steering rack is made from aluminum???
not 'the' cross-member. 'A' crossmember. specifically, from I-series 911 (1976) and newer, through maybe 1989 (maybe later). 911S and 912E. notably, NOT the 2,7 Carrera RS.
it -is- lighter. it is also a lot more flexible. (unlike the 911 rear trailing arms, where the aluminum parts were more rigid than the steel ones they replaced, for a double benefit ...) it is not a -lot- lighter, and the weight is just about as low in the chassis as you can get.
i was enamored of the aluminum crossmember until i researched it more. (a reference in Frere's '911 Story' led me to believe it was responsible for a suspension geometry change, but in fact it is identical, dimensionally, to the steel ones, and the geometry change was made to the I-Series tub...). if you're into lightness for its own sake, you might save a pound or two. i prefer to retain rigidity in my front steering and suspension, and the 20 lbs i can "easily" take off the driver are located much higher in the chassis...
911.341.013.10 if you want to track it through the years ...