Check this out, smaller ports make more power?

[jibberjive]

With all the talk of RS4 and 2.8 heads and intake manis, what do you all think of this?
http://mototuneusa.com/think_fast_intake_porting.htm

Has anyone done a before and after dyno of ONLY swapping the 2.8 heads or RS4 intake mani in?

[GURUMAN]

It's all good but there is no forced induction in the text book

[pit viper]

It's all good but there is no forced induction in the text book

True that. There's no "reversal of flow" with a turbo pushing more air in behind.

[RolledMySTi]

^^ Exactly. The article is good, but the principals don't apply when you are cramming 20+psi into the motor.

[Unispeed]

in the end its the same deal with exhausts too.. on a turbo no exhaust is best.. on a NA engine you might actually end up loosing power... with turbos, bigger in and bigger out seems to be better

[jutny]

the only issue here is port flow under boost is not as important because theres... boost, positive pressure, forcing its way in.

however, it is in vacuum or where you want the efficiency. size and restriction of the port actually makes a measurable difference in powerband. Bigger ports are nice but will equate to lower port flow velocity at any given rpm and effect the torque curve in a negative way.

my understanding of this leads me to believe that with 2.7 heads, no matter what, you'll have a more robust, slightly lower torque curve and the motor will be more efficent in vacuum. This is important on a turbo car where you have lag. The smaller port motor will be more efficent at lower rpms, therefore spooling a little faster, and yes, you'll lose top end flow, but why would you care, you can always boost more up top. You can't do anything about the low end.

did this make sense, i'm pretty out of it.