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- Cruising Around
Number of vanes definitely makes a difference and should be noted. You think a 14, quite a purchase to not be sure? Good luck and glad you are happy with the progress.
155 mm pump tune sugestions
- Thread starter rubbertoe
- Start date
D-Roc
I forgot!
- Location
- Dirty River Rider
I am running 6 vein and use a Yamaha fx140 turn nozzle. I may be wrong but the amount of veins will make the pump more efficient. If you look at the purpose of the veins then double the amount of veins, Each vein has less work to do. This should make the pump do its work faster and easier. I don't feel that more veins loads the motor more, actually the opposite. This is my opinion. Correct me if I am wrong.
I remember a discussion about 4 years ago about a 148 being too much for a 850--900cc. That was a messy discussion but it proved to me, that a lot of people have no idea how to tune a pump. I ended up putting a 155 in my ski and wAs able to tune it to load my motor identical to the way my 144 did. It took time and the proper parts but the end result is indeed a much better way to put the power to the water.
I remember a discussion about 4 years ago about a 148 being too much for a 850--900cc. That was a messy discussion but it proved to me, that a lot of people have no idea how to tune a pump. I ended up putting a 155 in my ski and wAs able to tune it to load my motor identical to the way my 144 did. It took time and the proper parts but the end result is indeed a much better way to put the power to the water.
D-roc i remember seeing a thread that featured your pump and the work it took to put it in ,kudos man . Wanderer also brought up a point about the veins and there possible effect on load and dynamics would lead me to believe that it would be more work to push water thru the higher number tighter spaced smaller veins than the larger more openly spaced bigger veins ,hence the difference in prop gearing .true it would be more efficient in the fact that you would get more thrust out of the same amount of water pushed out of a tighter pattern but may require a different gearing combo with any given displacement .but its this sort of discussion that brings to light the info on a tuning recipe for a good 155 set up .
D-Roc
I forgot!
- Location
- Dirty River Rider
The way I think about how to tune a pump is that The reduction nozzle diameter is what determines the load per given prop pitch. So if you open the reduction diameter more and more, eventually a 650 could slip a 9/15. So if you choose a prop pitch and start tuning with your stubby cone and go up in reduction nozzle diameter until you can almost slip your prop, your very close. If you do slip your prop, you have gone to big. That is why I got a skat gp1300 reduction nozzle with different rings. Once I got to the point my motor was slipping my 9/15, I went back down 1 size. Then I started to increase my tail cone size to physically reduce the volume behind the prop which will make the pump prime faster and give the end result of stretched arms.
D-Roc
I forgot!
- Location
- Dirty River Rider
I agree that discussion is what can help us all learn about dialling in a pump. As long as the discussion doesn't turn to the " my builder says this is the prop to run". I hate that because it is second hand information that is misleading to people that have no clue why a builder recommended a certain prop pitch. Also if you cannot adjust internal pump volume or reduction nozzle diameters, then I guess you will have to buy a bunch of props to tune your pump to the reduction nozzle size and tail cone volume. Seems backwards to me.
- Location
- amarillo ,tx
C-mon D, im not going there . this is more for out of the box thinkers and general knowledge .not just sheep talk . there is truly not very much info out there on this subject .man i knew it was going out on limb to even start a thread about things on the x that haven't been exploited with info ,so go easy on me .aquaholic is a different story he gets both barrels ! Lol.
D-Roc
I forgot!
- Location
- Dirty River Rider
I am not trying to sound angry or a know it all. I just type short. If we could see our faces when we type you would know I am not too serious guy. But I do like to hear how people are tuning their 155 pumps, just first hand information though. I would like to discuss how the extra veins would increase load on the motor a bit more.
- Location
- amarillo ,tx
I could c how number of veins help load pump, helps hold the water back bigger areas to release the water say on a 6 vein
D-Roc
I forgot!
- Location
- Dirty River Rider
I always figured if Yamaha switched to the 155 in the gp800 it was for good reason. I would compare my 771 to a gp800 motor so I knew it had to work. I had issues at first with my ATP turn nozzle. Way to small for that kind of volume. My reduction nozzle does not have the veins in it so I could see that my jet blast was very " messy" and corkscrewing into a high spread shortly behind my turn nozzle. The fx140 turn nozzle has the 4 veins in it and is for a 155 pump. Also a trim ring with blow back seal was a huge help on cornering. I run a few degrees of positive trim and it's set. I don't have a trim lever. I also made a flowgaurd style ride plate to protect the pump from water drag/interference. All that and I am so happy with my ski. Any 144 pumped ski I ride just feels like it has low pump-rpm response. I ran a 12/17 144 prop with my motor setup before and it hit hard. Just not as responsive feeling. Anyways that are some more of my thoughts on the 155 pump.
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- Location
- amarillo ,tx
Your 155 pump is a stock setup. Been considering running g a 155mm pump in my aquabot with my 771
D-Roc
I forgot!
- Location
- Dirty River Rider
But the volume of water isn't changing correct? I suppose if you can't change you compression at the reduction nozzle then maybe it would, I just don't see how. I am just talking out loud. I don't have a degree in hydro dynamics or whatever it is we are talking about.
- Location
- amarillo ,tx
Lol neither do I. I'm prob talking out my ass. Made since at the time
D-Roc
I forgot!
- Location
- Dirty River Rider
I have a TBM on my 155 so mine actually has a big hub like the magnum pump. But without the hub I can see the volume difference on oem vs mag. It is quite a bit. But I do think more veins will process the water faster and therefore help reduce drag which should result in less load which could result in a smaller exit diameter or, taller prop.
- Location
- amarillo ,tx
Good to know, this the one area I'd like to learn more about. What components need to b matched with the other.
Don't know if it works exactly like that . i think the more veins the increase in pump pressure & load on the drivetrain ,needing a steeper root angle.
D-Roc
I forgot!
- Location
- Dirty River Rider
We'll let me ask this then. If the mag pump does not flow better and easier why would anyone install it. I do know that they work better than stock. 100% proven. Why is this that they work better? We surely don't put them in so we can over load our motor and then run a lower pitch or bigger exit diameter is it? I like to run the tallest pitch that I can because that is how to move the water the fastest. If the pump can't handle the process of compressing it it needs to become more efficient not less. Again just talking out load to no one directly.