Loader Question??

[OLDMANSOLDSBOAT]

Will running a loader cause an rpm drop at WOT while at speed?? We're Running an A/T A cut impeller. If I stomp on it from a dead stop the rpm's Jump to about 4900-5000 then after about 4 or 5 seconds and alittle speed the rpm's settle down to about 4500 rpm's. It seams like maybe it's cavitating, but wouldn't that take alot of HP??

[Goober]

I am new to this but i have an idea. Sence you are now loading the impeller with more water then it should take more hp to get to the same rpm.

[Cas]

It seams like maybe it's cavitating, but wouldn't that take alot of HP??
nope, if it's a center blocker type loader it's possible to cavitate on the hole shot especially if you have some weight in the boat.

[Cs19]

Will running a loader cause an rpm drop at WOT while at speed?? We're Running an A/T A cut impeller. If I stomp on it from a dead stop the rpm's Jump to about 4900-5000 then after about 4 or 5 seconds and alittle speed the rpm's settle down to about 4500 rpm's. It seams like maybe it's cavitating, but wouldn't that take alot of HP??
Your probably just cavitating the jet. As the speed goes up you start to pick up some water and the pump is then loaded with water and the r's come down.If you stand on it from a dead stop you blow the pump dry before it can pick any water up.
It doesnt take loads of HP to cavitate a jet drive, if the pump is loose or the impeller is beat up it will cavitate even worse.

[OLDMANSOLDSBOAT]

Will running the loader show a noticeable drop in rpm's at speed compared with running no loader? In other words does it take more HP to turn the impeller if its loaded??

[centerhill condor]

I had a race loader installed this spring along with a complete rebuild and have no problem at hole shot and no noticeable increase at top end speed or rpm. However, I have noticed that the fuel lasts longer and at today's prices that helps. I was hesitant to get the race only loader as we have all kinds of sticks and debris in the lake. However, I haven't had any more or less problem with debris in the drive, yet. I plan to get the bottom cleaned up and expect more top end at that time.

[Cas]

Will running the loader show a noticeable drop in rpm's at speed compared with running no loader? In other words does it take more HP to turn the impeller if its loaded??
My son is going through the same thing right now. His boat had a shoe and ride plate when he bought it and when he had the pump done, he decided on putting in a stuffer and a loader. Along with the rebuild he also decided on a Legend B impeller with a pretty stock BBC. The boat now does 50.6 mph at about 4500 rpms providing the tach is right. He didn't really lose any rpm but he's pretty damn unhappy about only going 50.
He's trying to get the shoe off to do some testing but the ss bolts have pretty well welded themselves to the aluminum.
I think his pump is being overloaded for the power he has and the engine can't get all that water out fast enough. I don't think the loading is lowering his rpms though.

[IMPATIENT 1]

My son is going through the same thing right now. His boat had a shoe and ride plate when he bought it and when he had the pump done, he decided on putting in a stuffer and a loader. Along with the rebuild he also decided on a Legend B impeller with a pretty stock BBC. The boat now does 50.6 mph at about 4500 rpms providing the tach is right. He didn't really lose any rpm but he's pretty damn unhappy about only going 50.
He's trying to get the shoe off to do some testing but the ss bolts have pretty well welded themselves to the aluminum.
I think his pump is being overloaded for the power he has and the engine can't get all that water out fast enough. I don't think the loading is lowering his rpms though.
i have a buddy that done the same thing, he added a loader and stuffer, ran great.had pump failure and had a inducer installed on new shaft,b imp..lost alot of mph and rpm's.he overloaded the pump and needs about another 200-250hp to get to where he was runnin before.this was on a taylor sj like mine, heavy lake v-hull.i run a proloader,shoe/ride plate kit,stuffer,divertor,berk a,no droop or snoot and run mid 70's all day long, 80.3gps on the bottle and never unload the pump, which tells me more hp is needed to go faster!!!!!!