Originally Posted by Willie Williford
The whole intake system is complicated and is probably based on a combination of air and sound pressure/flow/capacity needs.
Still, I believe the resonator is there mainly for noise. The shape of the intake snorkel could be designed to "Stuff" as much air in the intake system at a low engine speed (rpm) air flow less, based on the pressure difference at specific loads and rpm.
Too complicated to fully understand.
Do whatever works for you.
Just wanted to reiterate that the resonator does indeed boost intake pressure at certain frequencies (rpm's) based on earlier testing that I did several years back.
For those that have been around engines for a while, there was the boost bottle rage back in the late 70's for two stroke engines.
Yamaha came out with an SAE paper that described the design and operation of "boost bottles" on their two stroke engines. I don't remember the exact model now, but that same year Yamaha released a 400 dirt bike with said bottle on it.
And just like the Insight, it was connected to the intake port.
In the case of the Yamaha, it was just downstream of the carburetor, and provided a low end rpm boost for those peaky engines.