Originally Posted by swamp2
I'd bet against 3200 lb, again strongly bet against it.
Cheap core materials like cardboard can provide stiffness improvements in large sheet like structures but would not be used for more complex mechanical/structural type shapes. Due to language difficulties (wheel mounts, axle stools ?) I am not positive, but many of the items you list do not seem like good candidates for replacement by CF, certainly not a CF/cardboard sandwich.
We keep hearing about the capabilities BMW gained when they purchased a large stake in SGL Group. However, they are touting much of the CF production from their new Moses Lake, WA facility to be slated for the i3 and i8 vehicles. They are also claiming that their new industrial (as opposed to aero******* grade CF will be about 50% the cost of traditional aerospace CF, thus about $10/lb, still over 10 times more expensive than steel.
For the sake of argument if they want to save 300 lb with CF that will take about 100 lbs of CF replacing 400 lb steel (super coarse "back of the envelope" estimate here). That will then cost just in materials at least $1000, not to mention higher tooling (fixed) and much higher labor costs (variable). I'd estimate the total cost (not price, cost) to save 300lb at about $1200. That must be increased further by their desired profit margin. It may not sound like a lot in a $60k car, but you would be amazed at what large automotive OEMs will do to save a few pennies on simple things like fasteners. $1200 is a HUGE expense.
Again there will be innovation, there will be weight savings, there will be increased use of composites, CF and lightweight metals. The car most likely will weigh less than the outgoing model. However, 3200 lb is just not going to happen.
Okay, sorry for my bad english ... some german technical words are not easy to translate.
But someone, from which I know that he sometimes could see secret M-GmbH prototyps, told me that he has seen an unpainted F80 chassis and that this parts I posted would be made from black composite material.
Also many officials from the M-GmbH quotes on M events that the new F80M3 would an great surprice (3.500lbs would be no surprice, because also the CRT reach this weight! for all M drivers and has radical changes in the materials, which would be used. And that the F8x could be seen as the material testcar for the coming 7er successor and the BMW lightweight strategy for the future.