Flow Rate on a Berk?

[Wet Dream]

Just curious, what is the flow rate (GPH) on a Berkeley, JC12 with an A at say 4500rpm?

[spectras only]

approx 4500 gallon per minute at around 5000RPM and approx 600-650 pounds of thrust.

[AGGRESSOR JETS]

Thrust sounds light, GPM sounds a little high. Our JR Drive pulled 875 pounds @ 4300 RPMs on a 7" impeller unit. We just pulled off a 4780GPM @ 6800 RPM- I to would like to know- if you have some data on this Sprectras Only would you send me it. Im trying to Log Log to find relative curves that make sence. Thanks Dave.
[This message has been edited by AGGRESSOR JETS (edited April 25, 2002).]

[spectras only]

Dave ,I'm getting the info for you,and can fax it to you .The numbers I posted were approximate from the top of my hat [it could have been the Mondello prepped 18 spectra],so I'll get the newer specs comparison chart for the early 90' by ATJ and Berkeley. BTW ,did you machined your impeller down to 7" to get 6800 RPM ?
[This message has been edited by spectras only (edited April 25, 2002).]

[SB]

I've been curious about this. Why don't the jet makers post this? It would seem that the pump getting the most thrust from a given hp is the best choice. My jetski with a 120 hp engine claimed 800 lbs. of thrust. Which doesn't tell you much except that it could go straight up.

[spectras only]

Dave & SB ,here are some specs,done in 1990.***boat should have it in the archives too! http://www3.telus.net/spectrasonly/ATJ.berkeleyspecs.bmp

[Wet Dream]

Great info. So basically, if I want to empty the local pool, I can put my boat into it and drain it in about 5 minutes. http://free.***boat.net/ubb/smile.gif

[AGGRESSOR JETS]

[QUOTE]Originally posted by spectras only:
[b] Dave ,I'm getting the info for you,
Thanks- Im trying to Accum data to make what represents today. We have a Race Team in Canada that detail collects and Tests on top of whats out there. I have seen some of the worst Impeller charts being passed around that don't fit the bill & I know our Impeller is not represented in the cuts or HP ratings.-
I have a Great chart of Aggressors "A" Impeller from 350 to 1700HP Based on actuals and 12-14 plot points. Most are Tunnel and a tunnel is 10-12 MPH and up based on HP-
Maybe if we could collect from all writers cuts to horsepower by type of hull-IE V or Tunnel and approx. running weight we could all get it right for publish.
My second reason for asking is Thrust -
Aggressor worked with and provided a Jr 7" Drive to a Engineering Co out of Detroit.
This Co. had a venture capatilist who owned a PATIENT on Retractable Wheels. WaLa- a Amphiobian Car.He contracted this company to Mock-Up,Design, and produce 1ST article Test unit. A full unit was produced in Alum. and a Test Engineer was brought in to set up & run all Tests. Craig of 4Winns was this person and a fellow Jet Racer. Craig had designed a Test pull Hyd. System that was simple and worked. I watched the Jr Drive Pull 875 pounds of static line with a 3.0 ford V6 @ 4400-4500 RPMs. I also seen this little pump kick ass over a Bigger Axial Flow Pump on same hull except it had a bigger motor Saburu- I learned that day after watching that a mixed flow pump drifts to find its water, a Axial Flow will suck untill it can not get its water, release and start again.
Im sure this is Pressure system vs Non pressure type pump-anyway Jr out pulled the Axial by 100 pounds.This Co. bought a brand new SeeDoo boat to run alonside of the test car, and not on hole shot but top end the car was faster.
So you can see why I had doubts on Thrust#
I also know a 12" kicks butt on Jr.
9" Imp vs 7"- Kick it around maybe all will want to get involved = we want to know-
Dave Jones Aggressor
I see your chart- GPM is maybe OK- Dan Nelson Unit pumped some 4780 in math based on computer peto tube basis. I had a friend of mine check his numbers- Mike Granados also a Racer and rebuilds Fire Pumps. Mike # was about the same.
I don't quite buy the charts shown because they are marketing based- but a point of referance- Maybe thats all needed. again thanks- Dave see if anyother responds to Input bases. Impeller must be Identified also.
I have flowed all impellers and flow rates go from 489 cfm to 516 cfm @ static- The cavatation factor jumped all over affecting the flow numbers. So each impeller should be
some how included in the base.
[This message has been edited by AGGRESSOR JETS (edited April 27, 2002).]