Re: Parallel Twinz vs. Compound Twinz
Well since you've listed mass flow, it's simple. If the first stage is moving 140lbs/min then at every point in the system you are still moving 140lbs/min, unless you're going nuclear and gaining/losing mass. In which case the power is going to go out of sight. Course you'd better be wearing 400,000,000 spf otherwise you're going to have a really bad day. lol.
But in all seriousness. How are you moving 160lbs/min of air into the engine when the first stage is only moving 140lbs/min? The first stage compressor is responsible for bringing in all of the air for the system. You will not move any more air than it can physically flow.
And the A/R for the second stage should be chosen based on the goal for the vehicle. If absolute response is paramount (see my thread in the smack talk section for further explanation of my view on this) then you can justify potentially sacrificing some losses to exhaust drive increases and ultimate power. I personally run the largest housing made for the second stage. I think it spools well. Others may think it's laggy as can be. But that is mostly subjective anyway.