Originally Posted by SVOboy
I believe it is less airflow per throttle position, more throttle, less pumping losses, therefore equal power for less.
i don't get it. help me out here.
assume 2000 rpm constant load and no restrictor plate. let's say the throttle is open at 4 out of 10.
now add a restrictor plate. to maintain 2000 rpm, now the throttle must be open to, say, 6 out of 10.
since we're at the same engine speed (load/power output), we must be consuming the same amount of energy (gas), and also inhaling the same amount of air.
it seems to me like all we've done is shift the location of the intake restriction from the throttle plate towards the restrictor plate - with no net change in pumping losses.