Loader vs. RPM's

[HotDogz]

Will installing a loader reduce your rpms by loading the pump more than normal? 35 hours on stage 2 pump w/loader spinning B impellar to 5100 rpms @ 65 mph. (no shoe or ride plate yet) I dont feel like these numbers match. But I'm new so some input would be appreciated.

[MudPumper]

Maybe 100 rpm, 200 at the most

[Squirtin Thunder]

Maybe 100 rpm, 200 at the most
That rpm is a little hi with out all the details so by putting a loader on of some sort the rpms will drop and you will go faster in most cases. A place diverter will also help a ton.
Jim

[HotDogz]

My current setup is a .060 over 455 w/speedpro pistons, 292 CompCam,
Torker intake, 2 inch carbspacer, marine Holley 750 w/mech. sec., Bassett water jacket headers(4 inch collector) all fired by an MSD ignition. My bottleneck would have to be my heads, stock Ga heads cut to accept large Ferrea SS valves. Whole setup has 35 hours on it and I just felt like I should be making more power. According to Berkely impeller curves, I am not even making 400 horse. :confused:
So my original question is if by installing my loader, does that make Berkely's horsepower chart inaccurate?? And shouldn't I be going faster as well? 70 maybe. I am also already using a place diverter.

[Taylorman]

My current setup is a .060 over 455 w/speedpro pistons, 292 CompCam,
Torker intake, 2 inch carbspacer, marine Holley 750 w/mech. sec., Bassett water jacket headers(4 inch collector) all fired by an MSD ignition. My bottleneck would have to be my heads, stock Ga heads cut to accept large Ferrea SS valves. Whole setup has 35 hours on it and I just felt like I should be making more power. According to Berkely impeller curves, I am not even making 400 horse. :confused:
So my original question is if by installing my loader, does that make Berkely's horsepower chart inaccurate?? And shouldn't I be going faster as well? 70 maybe. I am also already using a place diverter.
I have a similar engine. I tried a B impeller once and got more rpms's with less mph. I gained 200 rpm's with a B impeller but lost 3 mph. I think you should be running an A impeller with your stock engine. Im currently turning 4800 rpms and best mph is 66.7 on GPS.

[UBFJ #454]

"Will installing a loader reduce your rpms by loading the pump more than normal?"
Depends on the design of the Loader ... On how much water the Loader causes to be delivered to the Pump Impeller ... Loaders are simply 'Water Directors' directing the h2o they 'Catch' coming off the keel/bottom of the boat to the face of the Impeller.
All Loaders are different and will effect the pump charge differently in different hulls ...

[Danhercules]

I am at 5500 with at B GPS at 72. that was without a loader. With a diverter. The diverter makes a big diffrence on speed. so, with out a diverter, I would say you are close, get a diverter and your speed should increase close enough to make the numbers match. That my guess. But I aint no pro.

[OkieDave]

Altho I currently have diverters on all my boats, my experience from racing years ago was the diverter actually cost me some mph. once the optimum nozzle angle is established, you don't need to change it.

[cruser]

OkieDave,
You are correct for a boat with a constant load that is used in a narrow range of water conditions, like a race boat. However, in my boat, I adjust the diverter to compensate for the number of passengers, fuel load, wind driven chop, pulling skiers/wakeboarders, etc. True that the boat is pretty good at one angle, but it runs just a bit better after these adjustments.

[LVjetboy]

"Will installing a loader reduce your rpms by loading the pump more than normal?"
It certainly could, but how do you define normal? If your impeller was cavitating before the loader and not after, than sure, your rpms will go down. But if your impeller was loaded before, than adding a loader may not change rpms much.
"I just felt like I should be making more power. According to Berkely impeller curves, I am not even making 400 horse."
Don't forget, those curves are actual power delivered the the impeller, not engine "rated" or corrected power at peak hp. That can be a big difference.
jer