The density of the fluid has great effect in Bernoulli's equation. Another factor not in the equation is friction loses. Because the fuel has greater density and viscosity, it needs more pressure to get the same ratio of flow between air and fuel, because of this the mixture leans out as the air velocity increases. Ram air will improve induction, however as mentioned the dynamic pressure is not huge, but any improvement will also cause an improvement in flow so the pressure is negated by the reduction of static pressure. Automobiles used to get around this by using metering rods and extra jets activated by the increase in manifold pressure.