[mwebb]

well since there is no combustion taking place yet there is a huge difference in the amount of pressure in the cylinder between
wide open throttle and closed throttle , it would seem the pressure difference can be attributed to change in the ability of the engine to pump air into the combustion chamber

with a closed throttle as opposed to wide open throttle

with extreme suction throttling losses or almost no suction throttling loss

that difference clearly exceeds 5% .

back pressure at higher flow is measured at under 5psi but back pressure varies with flow and is negligible at flow under 50%

suction throttling losses also vary with flow
but even at MAX flow with over 4 psi measured back pressure there is over 4x more pressure in the cylinder without the suction throttling loss imposed by the closing of the throttle plate .

Originally Posted by mort

Hello mwebb,
I've studied your graph and read your posting, but I can't tell what you are asking. Please elaborate.
-mort