Well, some of the Mythelogy pulleys are 5% undersized. It's not enough to affect the accessories but it's small enough to make the accelerator lighter (in terms of feel).I read some article from Dinan BMW that said, undersized pulleys would affect the accesories (water pump, air con, wtv is attached to the crank pulley) at idling speeds.
i agree that there's not much effect on SOHC....
but on DOHC car....they made a whole lot of different...
its like u have 2-3sets of stock camshaft from different engine spec. to play....
especially when u change the overlapping duration of both camshaft...
p/s:however stock setting still the best balance between fc and performance....
Really? Ok. I'm a DOHC newbie so I didn't know you could mess with stock cams like that for DOHC.