Inducers are interesting devices.
The basic idea behind them (bear in mind this is from the 1990's) is to take some of the work away from the impeller having to "pull" the load from the bottom of the intake, if you look at the intake area where and inducer would reside you would see that there is a lot of real estate between where the water is to where the first edge of the blade of the impeller touches the load.
The inducer basically does two things. One, it pulls water into the suction piece and actually loads the impeller. Two, it acts as a pre rotaion device, getting the load rotating in the right direction before being pumped, both of these functions increase overall impeller effect (in theory) and they are a very trial and error. Most of the time I would say they help in one form or another but the horsepower requirement would be higher IMHO, typical 350 HP setups I don't believe can benefit, but the 800 HP high RPM monsters could really take advantage of them...
In short, think of them like wide sticky rear tires on a muscle car that can fry conventional tires for as long as your right foot is touching floor mat.
I have run the same boat, both with and without and the difference for us was being able to keep your foot on the go pedal in rougher water at speed (70-85 MPH), no other difference was noted (all seat of the pants and open for interpretation).
GT
