Ten pounds off rotational, you talking engine, or drivetrain? Engine I'm assuming since it's what accelerates the fastest.
You all know that nothing is as insane as WOO sprint cars for light weight, aluminum rears, aluminum spools, lightened gears, carbon fiber driveshafts, direct drive clutch, no trans, coupler to the direct drive box, super light cranks, rods and pistons and if it ain't made of titanium or unobtanium your in the back of the pack. And yes, there are titanium connecting rods.
Probably correct, but there's a point where light weight and durability cross.