The low HP could be due to pressure drop not cross flow. The intercooler and the length of piping dampen pulsations if any at high freqency. The turbo compressor is spinning at very high speed. It may speed up and slow down but how much between exhaust pulses? How long does it take for the boost surge to get to the intake valve by the time it goes through all the piping and the expansion and contraction in the intercooler? The compressor is spinning at a very high speed over 100K rpm. The valve train spins at half the speed of the crankshaft. Yes, little things count and add up like convential oil and synthetic. The intake valve doesn't care which turbo supplied the boost, as long as it is their when the valve opens up. That boost pressure in the manifold is constant or appears constant . It doesn't go from 20 psi to 0 psi or 1 psi when the turbo is not getting an exhaust pulse. The turbo wheels acts like a flywheel and keep spinning between exhaust pulses.
