[ddog]

Does anyone know of a valve control-system for dual EFI intake runners:

"The downside to using smaller diameter intake runners is that at high engine speeds when lots of air is going through the pipes, the restriction from the smaller diameter may inhibit airflow. So for the large airflows at higher speeds it is better to have large diameter pipes. Some carmakers attempt to get the best of both worlds by using dual intake runners for each cylinder -- one with a small diameter and one with a large diameter. They use a butterfly valve to close off the large diameter runner at lower engine speeds where the narrow runner can help performance. Then the valve opens up at higher engine speeds to reduce the intake restriction, increasing the top end power output. "

It sounds like simplified turbo power, without a turbo - ??? Each pipe-size power-band would be about 3K rpms, which for me would be perfect.

EFI and/or turbos would need this it seems anyway.