ORIGINAL: JeffH
It unloads a HUGE amount in the air. I have to launch(its on a whiplash) with the engine well below peak, if not it will go lean in the air. It is just difficult to find the right needle setting to launch to get max performance without going lean.
i've also had this problem with bladder fed engines and the best solution is inflight mixture control. this allows a quicker launch because you don't need to be so rich when on the ground.
dave