Help with rudder prop selection pwc converted to propeller

[RUNWME]

Hi guys, my name is David Bunn and I am first time poster.

I have done a propeller conversion on a 2005 GP1300R waverunner and would love some help getting it sorted out. I looked all over the internet to find what was closest to my setup and I think an inboard hydroplane would have many similar setup features.

If you can help with any of these issues, I would really appreciate the feedback.
Basics....
2005 GP1300R running direct drive 200hp 620 lbs currently running a triton 10 in diameter 4 blade left rotation ssm prop my propshaft is 1in diameter with standard 15splines Best speed so far is 92 at approx 6100 rpms and 60% throttle peak rpms is 7200 and target speed is 105

This is all a work in progress, and things change weekly but below is pic of current setup and a video (have 3 posted on utube)

The problems that I am having is that when cruising, it takes a lot of steering to counteract the torque.
Part could be propwalk as my 10 diameter prop is 2.5 inches above bottom of hull. ( so only 2.5 in of blade in water)

I have been suggested to mount just one rudder on the left side because the drag of it would help offset the right turning. I also think I need more of a bow lifting propeller (instead of stern lifting I currently have) to give more bite with high propshaft.

my questions are...
1 would a left only mounted rudder cause enough drag on left side to help counteract torque? (below is a new rudder I was considering making out of 1/2 aluminum and having water pickup in it, and torque tab on back right)
should i go with just 1 rudder or 2?

2 would a round ear or drag style propeller let stern ride deeper and give needed bow lift? anyidea where i could find one?

3 Currently I have 2 3/8s water pickups which provide plenty of water. One is just raming into engine, and other feeds a shurflow waterpump (for idle speeds) is this how most guys do it, or do i need more or less? I have never run warm or hot with this setup, but dont know what will happen if I go to one rudder (and 1 pickup?)

thanks in advance for any input you offer..... I am doing best I can with this project

current propeller.. ventilates badly out of hole, and doesnt get enough bow lift


current setup, those little wings on rudder were an experiment i did this weekend to try to keep rear planted and offset the lifting of the clever prop and dual rudders.
The wings were very helpful in keeping back in planted, but made my rudders wash out at higher speeds (will redo my rudder mounts to very solid transom mounted rather then just bolted to top deck which allowed movement)


a pass



rudder I drew up to build... think its ok, need bigger or smaller?


a youtube video.. I have 3 posted from this weekend
http://www.youtube.com/watch?v=hr2GSTvXPt0

[RUNWME]

http://www.youtube.com/watch?v=Vz8eVxlr7ew
another short video of maiden passes

[David Weaver]

Wow

How stable is this craft? You might consider building some type of cage around the propeller to provide protection in the event that you fall off of it. Are these sppeds in MPH or KPH?

[RUNWME]

How stable is this craft? You might consider building some type of cage around the propeller to provide protection in the event that you fall off of it. Are these sppeds in MPH or KPH?

Its great on stability! I was really surprised how well it does. It has porpoise up until 35-45 mph then it will take a set and accelerate with no chine walking or bounce even at higher speeds. When going over wakes, it stays hooked up (where the jet would suck air)

The speeds are with foreman GPS in mph


I had a stv with 300 drag and cougar 21 with twin 300s, so really respect the water on highspeed runs.

I get asked about safety measures a great deal....And for safety I run a shortened lanyard (engine cuts off if I remove my hand more then 6 inches from handlebars) and always make sure I have someone on hand when testing. Before doing high speed runs, i put on a 5mm full suit, a lifeline vest with kevlar , neckcollar and helmet. In the video I posted, I never took speeds over 60 as I didnt have the proper protective gear, and I always make sure there is a boat spotter filming and also to be there in case something bad happens. For protection from propeller, I have a wing that extends off the back deck with sides that come down on either side of propeller. While I am sure its not as safe as with the jetpump, I am consciously thinking about safety everytime I get around it.

[RUNWME]

How stable is this craft? You might consider building some type of cage around the propeller to provide protection in the event that you fall off of it. Are these sppeds in MPH or KPH?

a question.. I have seen some propgaurds that circle the propeller very tightly... I wonder if that would help direct the thrust rearward and reduce torque?? I would really just want it from center of propshaft up like a half circle (full circle I think would have too much drag in water and cause handling problems?

[RUNWME]

http://www.greenhulk.net/forums/showthread.php?t=47449

here is the building thread on highperformance pwc forums..25 pages long

[Rich Russo]

Wow...

...and folks think us kneel-down racers are nuts Glad to hear your wearing safety gear. Oh yea, I probably don`t need to tell you to have fun!

[RUNWME]

[QUOTE=Rich Russo;99635]...and folks think us kneel-down racers are nuts QUOTE]


You kneel-down racers ARE NUTS!!!

[johnsonm50]

[QUOTE=RUNWME;99643]

...and folks think us kneel-down racers are nuts QUOTE]


You kneel-down racers ARE NUTS!!!

Thats cool David, Im wondering about the avatar pic, is that a 3 point hydro type pwc? custom made? I see it isnt what your running in the pics of this post. Mike

[RUNWME]

"its a 275 hp 4 stroke laser x2000 that was made by swift oceanics... they took deposts, but never went into production with them... they claimed 90mph jetski back 5 years ago...."
I tried to do a little research.

Swift Oceanics is no longer in business,The ski was Reported to break 90 MPH.
The hull was alumiun.There was a big uproar about the sponsons being deadly,combine with the speed....I read were the CEO said the ski "will have built in break away sponsons, made of hard foam rubber so that if someone does run into an object or person less damage
and more importantly people won't suffer the way they
would from being struck by that of a hard composite
material."
The owner (Darrell Miklos) left Cali. and moved to Arizona to put in a new boat manufacturing plant for a few years. My understanding now is he is living between the Bahama's and Mexico.

Here's a interesting converstion about it being discussed.

http://www.woodenboatvb.com/vbulleti...p/t-29065.html

Here's another article on the company.
http://www.popularmechanics.com/outd...56.html?page=2

[johnsonm50]

Hi guys, my name is David Bunn and I am first time poster.

I have done a propeller conversion on a 2005 GP1300R waverunner and would love some help getting it sorted out. I looked all over the internet to find what was closest to my setup and I think an inboard hydroplane would have many similar setup features.

If you can help with any of these issues, I would really appreciate the feedback.
Basics....
2005 GP1300R running direct drive 200hp 620 lbs currently running a triton 10 in diameter 4 blade left rotation ssm prop my propshaft is 1in diameter with standard 15splines Best speed so far is 92 at approx 6100 rpms and 60% throttle peak rpms is 7200 and target speed is 105

This is all a work in progress, and things change weekly but below is pic of current setup and a video (have 3 posted on utube)

The problems that I am having is that when cruising, it takes a lot of steering to counteract the torque.
Part could be propwalk as my 10 diameter prop is 2.5 inches above bottom of hull. ( so only 2.5 in of blade in water)

I have been suggested to mount just one rudder on the left side because the drag of it would help offset the right turning. I also think I need more of a bow lifting propeller (instead of stern lifting I currently have) to give more bite with high propshaft.

my questions are...
1 would a left only mounted rudder cause enough drag on left side to help counteract torque? (below is a new rudder I was considering making out of 1/2 aluminum and having water pickup in it, and torque tab on back right)
should i go with just 1 rudder or 2?

2 would a round ear or drag style propeller let stern ride deeper and give needed bow lift? anyidea where i could find one?

3 Currently I have 2 3/8s water pickups which provide plenty of water. One is just raming into engine, and other feeds a shurflow waterpump (for idle speeds) is this how most guys do it, or do i need more or less? I have never run warm or hot with this setup, but dont know what will happen if I go to one rudder (and 1 pickup?)

thanks in advance for any input you offer..... I am doing best I can with this project

current propeller.. ventilates badly out of hole, and doesnt get enough bow lift


current setup, those little wings on rudder were an experiment i did this weekend to try to keep rear planted and offset the lifting of the clever prop and dual rudders.
The wings were very helpful in keeping back in planted, but made my rudders wash out at higher speeds (will redo my rudder mounts to very solid transom mounted rather then just bolted to top deck which allowed movement)


a pass



rudder I drew up to build... think its ok, need bigger or smaller?


a youtube video.. I have 3 posted from this weekend
http://www.youtube.com/watch?v=hr2GSTvXPt0

Often enough to always think twice- things that look one way are another, that said it looks as if the wing rudders might cause the nose to set deep because of the leverage off the depth of them. The single offset rudder might solve 2 things if ya get the depth/tork tab and pivot point right. The prop is another story where testing will answer the question. At just over 3# per hp, whoo hoo! Its fun to be nuts

[david bryan]

boys and there toys

i have only one ? why

[RUNWME]

How about this rudder, just mounted on left side

Its 3/4 wide in back and tapers to 1/8 in front

[crfabbro2F]

Very cool prject! A wedge rudder will have the least amount of drag.
Take a look at rc race boat hardware for design ideas. I would not use
a short and wide rudder for sure. Prop walk is going to be almost impossible
to eliminate on a surface drive with a single prop.

[jphii]

i have only one ? why

Cause he's nuts!! And how many people do you know that have been over 90 on a PWC?

David is a friend of mine and we've talked quite a bit about this project. I keep telling him to try and run this 13x24 on it that I have, but I think he's scared.