Originally Posted by swamp2
As others have posted perhaps not quite at succinctly, the likely power to weight (weight to power...) ratios are:
3550/450 = 7.9 lb/hp
3850/480 = 8.0 lb/hp
That is less than a 2% difference. The 300 lb will give the M4 some significant handling and braking advantages. My prediction is that the cars will be basically a drivers race in a straight line. However, pretty well all of the journalists test metrics will have the M4 edging out the RC-F. The margin of victory will be wider on anything twisty.
Can I ask where you got your 3550lbs weight for the M4? The weight annouced by BMW is 1500kg for the manual and 1540kg for the DCT, that's 180-250lbs lighter then your prediction, curious to know why you think BMW would lie about that! Is it because they underate their engines that you think they also underate their curb weight!?
But seriously, I totally believe the weight announced by BMW since their new philosophy of construction is all about cutting weight! Also I don't think this would be a drivers race between the two(if the new RC-F really weight around 3900lbs) simply because I think the S55 wil have alsmost the same amount of peak power as the Lexus V8 but will have a lot more power under the curve and most importantly A LOT less weight to carry! With the announced weight of the RC-F I think the car will be a closer race to a DCT e9x M3!
p.s. Can't wait to see those cars in action!!