Thread: Rxp Pump Mod... Todays Results
09-12-2007, 10:51 PM #1
Rxp Pump Mod... Todays Results
Well, I have been lookin for some ways to improve the pump on my rxp. The first place I was thinking of was where the wedge bolts in between the pump and nozzle. If u think about it the wedge brings the vains in the nozzle apart from the vains in the pump leaving a gap. So with the gap in between the pump and nozzle vains, the water must lose it's stright track out of the pump and get crossed up between the other vain tracks. I'm thinking the gap must be making for a loss in thrust. If u look u may see the tail cone is also not centerd in the center of the nozzle as well. I would think the tail cone could use the same 2 deg angle as the wedge to help get the water flowing out at the same angle as the nozzle. I'm hopeing to improve on the hole shot, acceleration, and maybe some top speed. So Today I did all the machining to the pump and wedge and did some testing as well. I also setback the impeller as well.
I did manage to get some testing in tonight but it was dark and windy not realy good water for testing. The first thing I noticed is the the throttle responce off idle was a bit snapper. So here goes with 1/4 tank of gas the first thing I felt was a better hole shot, the ski seemed to jump out of the water a bit more than before...I needed to trim down a bit more on the hole shot. The next thing I noticed was the ski was pulling much harder than before My top speeds were all just over 78mph 78.3 best @ 8160-8180rpm. There was a bad cross wind I had to keep the bars turned a 1/4 just to keep the ski going stright. I hope to have some good weather soon so I can do more testing!!!!
So heres some pics.
09-12-2007, 10:55 PM #2
i swear i have been wanting to try the same thing because i knew the tail cone would not be centered after a wedge install and thas why i do not run one. I just wish i knew someone with a machine shop
09-12-2007, 11:21 PM #3
how do you set back the imp.?
and how much do you set it back?
Last edited by DIGGS; 09-13-2007 at 06:14 AM.
09-12-2007, 11:42 PM #4
DIGGS, I set back the impeller .080 from the mating surface i don't touch the front.
meeper, After some more time with testing and all works welll i may offer this as a service. It doe's requires quite a bit of time and machine work.
09-13-2007, 03:05 PM #5
Eric, I looked at the pics, but was not sure of what you did ... did you machine the pump housing edge/lip so that the pump vanes now almost meet the nozzle vanes, even with the wedge in place? And also machine the tailcone mounting surface so it now has a matching 2 degree angle?
09-13-2007, 04:38 PM #6
same here i didin't quit understand about the first picture with the pump machining?
09-13-2007, 05:28 PM #7
He basically shortenned the housing or mating surface where the wedge goes. Looks cool!
09-13-2007, 05:40 PM #8
isn't there a part you can buy to do the same thing? an angled spacer that goes between the pump body and the cone.
09-13-2007, 05:43 PM #9
riva has a angled pump cone.
09-13-2007, 08:07 PM #10
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