so this has me confused... if we're saying that in the 330i the optimal condition for high RPMs is with both flaps open and all chambers/paths being utilized and in the 325i the intake manifold is missing these "flaps", which would imply they are open I'm assuming, then why wouldn't the 325i make just as much torque/hp in the high RMPs?
After reading this technical explanation I would think the 325i/328i US cars would only suffer lack of torque in the lower RPM range since the intake is optimized for high-RPM. I know RichReg has posted that both intakes are otherwise identical.
So is the difference in top-end power reduced only to ECU programming? And if so, why haven't tuners extracted this power yet?
I'd love for somebody to shed some light on this... I'm sure I'm just missing something...
And thanks for posting this info. I've always wanted to see how this thing works.