I'm with Ace, what you are seeing is too much W/M
AFTER you've gotten off the throttle.
I'm assuming you're working with an adjustable Hobbs type pressure switch.
I'm also assuming you're running the 150psig pump . . . . ?
If that's the case, consider raising the pressure switch to no less than 20psig. If it were me, I'd raise it to 25psig. That will help have the system NOT come on unnecessarily with normal driving. It will also help with the quenching of the fire when getting off the throttle.
You may also consider not running the 6gph nozzle with the 12gph . . . .for now.
Think about the 38psig boost canceling out 38psig pressure available from the W/M pump. If it's a 150psig pump, minus the 38psig boost, then there's 112psig pressure for the nozzle(s). It's my understanding that most cooling-mist nozzles are rated at 100psig (actual NET pressure at the nozzle). Running the two nozzles will mean that neither is getting at least 100psig
each. As such, they tend to dribble more than mist (if they were the same in size, one could divide the pressure to see more accurately what they're getting).
That stumbling after a hard pass is the W/M that's all over the inside of the charge-air plumbing, etc still getting into the cylinders . . . . with now much less air and fuel to burn it off.
