Reply With Quoterpms seem alittle optimistic for the hp#'s on that chart, aleast that has been my experience. If it works for you ok, no worky for me.
Well, it doesn't work for your application what can I tell you?. I listed 6 for you that it did work for. Not race boats but ok river runners. Mine runs 103., should and could be faster ,but that's all she'll do.
It seemed to be in the "Ball Park" for Pops @ Aggressor, but he may just have the same experience that I've had. From MPD's numbers it is off by 100 HP at a given rpm for his blueprinted pumps. Your 160 is excessive and this chart wont work for your application.
For the "average guy" it does give him more info to work with than the old Berkley chart does it not?:idea:
rpms seem alittle optimistic for the hp#'s on that chart, aleast that has been my experience. If it works for you ok, no worky for me.
rpms seem alittle optimistic for the hp#'s on that chart, aleast that has been my experience. If it works for you ok, no worky for me.
Just asking, how far off? I see why BP doesn't use it , his #'s are off a shit load. I forgot to ask him if he has a standard intake or a low profile unit.
Thanks, you get the point. I guess I should have started off with a big disclaimer saying it won't work for everyone, but it's better than the stock Berkley chart. I came close to saying that on the other thread before I moved it here.
Sleeper CP
i just think jer's jpc would be a lot closer to accurate because he got a lot of input from a lot of different people, much more recently, and for a variety of pumps with different size impellers.
i just think jer's jpc would be a lot closer to accurate because he got a lot of input from a lot of different people, much more recently, and for a variety of pumps with different size impellers.
Who? It would be nice to see a performance chart produced by someone else. The Jac Sea chart is the only performance chart I have ever seen. I know people like Jac at MPD could make one real easy, but I know they see all of their race knowledge as proprietary(as it is) so they aren't going to share it for free.
Does you boat have a standard intake in it or low profile?
Sleeper CP
Just asking, how far off? I see why BP doesn't use it , his #'s are off a shit load. I forgot to ask him if he has a standard intake or a low profile unit.
Thanks, you get the point. I guess I should have started off with a big disclaimer saying it won't work for everyone, but it's better than the stock Berkley chart. I came close to saying that on the other thread before I moved it here.
Sleeper CP
Everything Bob does is off the charts!
Both of you guys BP and Sleeper are number nuts! I would love to get you guys together with a 12 pk and watch all the s$it pour out.
Hi Neil,
Would you get to work so that you can make room for my f---ing boat.See ya tomorrow afternoon at the dyno.
Jon
wow that chart puts me down low
my mill on the desktop dynos at 516hp at 5500rpm.
i turn 5400 with a b-cut impeller.so thats saying im putting close to a whopping 400 to the shaft.that sucks ass.
i know the desktop maybe off some and thats fine with me i know i dont have alot of power but do you really lose this much to the pump that seem like alot to me???.
Everything Bob does is off the charts!
Both of you guys BP and Sleeper are number nuts! I would love to get you guys together with a 12 pk and watch all the s$it pour out.
thanks neil, i needed that
Who? It would be nice to see a performance chart produced by someone else. The Jac Sea chart is the only performance chart I have ever seen. I know people like Jac at MPD could make one real easy, but I know they see all of their race knowledge as proprietary(as it is) so they aren't going to share it for free.
Does you boat have a standard intake in it or low profile?
Sleeper CP
jer, "lvjetboy".. haven't seen him around here for some time, but i think squirtcha kept up with the jpc. jer collected a lot of data from a lot of different people to develop the thing. yes, jack and dave could make one, but there are a lot of variables, and within a certain range, it's not really going to matter (as you mentioned before, how far do you go to pick up that last 50, or 30 hp?). also, as you mentioned, "ballpark", but to me, this old berk deal is still in the parking lot, with respect to absorbed hp/rpm. graphing the hp off the dyno can tell you where you are, and whether or not you want to go further.
my boat does not have a standard intake in it, but that's only about loading at speed, not about impeller sizing. my pump does remain hooked up.
wow that chart puts me down low
my mill on the desktop dynos at 516hp at 5500rpm.
i turn 5400 with a b-cut impeller.so thats saying im putting close to a whopping 400 to the shaft.that sucks ass.
i know the desktop maybe off some and thats fine with me i know i dont have alot of power but do you really lose this much to the pump that seem like alot to me???.
desktop isn't quite the same as actual dyno testing, but i digress.
what the chart says is, to turn a b impeller 5400, a little over 400hp is absorbed. that may be a little off.
in my view, and this is just imo, actual dyno testing on calibrated dyno's is more accurate than any of these charts, as long as a bunch of modifications aren't made after the engine comes off the dyno that would alter the hp. if you have the pump properly loaded, and you get the top rpm the pump absorbs, it can be compared to your dyno graph and you will know how much hp is being absorbed by the pump.
my boat does not have a standard intake in it, but that's only about loading at speed, not about impeller sizing. my pump does remain hooked up.
That's interesting I would think that the intake ramp would be one of the biggest contributors to the RPM's. But, I'm just quessing so please correct me if I'm wrong: If a standard ramp loads an impeller at 25 psi at the wear ring with 250 gpm(example only) and a low profile ramp loads it at 48 psi with 400 gpm(example only) there wouldn't be a dramatic change in RPM's ? load on the pump ? :idea:
Help me out here.
Jon
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