hmmmm, i think 4throttle is invented to produce quick respond, preserving stablity on the flow. coz i used to drive a 70mm tb engine before, very tricky to control below 1500rpm.
If you add ITB @ single bigger TB, contributed to a better flowing head (doing PNP, gasflowed etc) ,add more aggresive cams and then better designed exhaust system, i'd say you've pretty much maximized your airflow into the cylinders. there's gonna be good power to be had on the upper rev range.
but the trade-offs that come wit it (something like you experienced there), you must compensate oso. power you wan, reliability you wan oso? kenot arr..
yin-yang maa...
