i agree gm has change a lot in the alli for the LBZ and this is probly how they get it to hold more tg and hp with out making costly changes to the insideI could be wrong, but i think it is to keep from tearing the guts out of the tranny. it defuels to relieve some of the hit when it down shifts.
if the engine doesn't produce any more rpm how is the turbo spooling up?This issue came up on the transmission board. There's a couple of things going on. Assuming that you guys are going to WOT at 55MPH the trans is likely doing a 5-3 downshift. When this happens the engine needs a couple of seconds to spool up the turbo to make power. Until it does you're just going to sit there.