ok. i know how 70mm TB's are can be too large most 1.8L motors.

but i was really just wondering the theory behind this, and how it works and what not. and how much proof is there to the theory that you can have too large off a throttle body.

because you always hear that more air equates to more power, but is there any proof that say a 67 taper to 64 TB could outperform and out flow a 70mm peice from like RPM or something on a 1.8L?

i was just wondering this last and couldnt find any hard fact in my numerous searches (before i fell asleep )

TIA

 

Getting the most air in an engine is always a compromise between flow capacity (big hole) and flow velocity (small hole). You have to find the right balance between the two because an engine draws air in and pushes exhaust out in pulses and not a steady flow. When a high velocity is maintained it creates a ram effect on the intake side and scavenging effect on the exhaust. Dan

 

so having a nice taper is important? could you have too much of a taper

like say 74 tpaer to 66mm