Adding trim to 15f

[dcuhpw]

What is your goal for the tabs?

Sean

I like the setup you had on your nasty build. How well did they work for you?

[smokeysevin]

I like the setup you had on your nasty build. How well did they work for you?

Thanks, I am reasonably happy with how they turned out. A couple notes on them, make sure you round any edges on them, bashing your shin on a sharp piece of aluminum under the water line sucks ass.

Strictly speaking, you don't need return springs but they are nice for adjustment out of the water. As long as your pivots are free moving, the water moving over the hull will pop them back up really quickly.

Mine are pneumatic and are really quick acting but loads of people used to use cable operated ones which is nice since your cable never runs out of air. People also used to use hydraulic mountain bike brakes or mx brake cylinders to actuate them.

This type of trim tab only acts to keep the nose down, they might help porpoising if you have too much lift from another components but based ony my limited time with them, they aren't going to magically add speed. I didn't run them for all that long. I played around with them a bit while I was tuning the first version of my motor and then took the whole ski apart to redo the intake setup.

I think I would try to figure out why the ski is bouncing before spending too much money/time on adding other parts to correct it. I never had an issue with mine being stable unless I was riding 3 up just above no wake speed.

How does your rideplate fit the hull?

Did you seal the edges?

What intake grate are you running?

When you did the work on the hull did you alter the shape at all?

Sean

[dcuhpw]

Thanks, I am reasonably happy with how they turned out. A couple notes on them, make sure you round any edges on them, bashing your shin on a sharp piece of aluminum under the water line sucks ass.

Strictly speaking, you don't need return springs but they are nice for adjustment out of the water. As long as your pivots are free moving, the water moving over the hull will pop them back up really quickly.

Mine are pneumatic and are really quick acting but loads of people used to use cable operated ones which is nice since your cable never runs out of air. People also used to use hydraulic mountain bike brakes or mx brake cylinders to actuate them.

This type of trim tab only acts to keep the nose down, they might help porpoising if you have too much lift from another components but based ony my limited time with them, they aren't going to magically add speed. I didn't run them for all that long. I played around with them a bit while I was tuning the first version of my motor and then took the whole ski apart to redo the intake setup.

I think I would try to figure out why the ski is bouncing before spending too much money/time on adding other parts to correct it. I never had an issue with mine being stable unless I was riding 3 up just above no wake speed.

How does your rideplate fit the hull?

Did you seal the edges?

What intake grate are you running?

When you did the work on the hull did you alter the shape at all?

Sean

im running the worx grate. Here are some pics of my setup. I didn’t mod the shape of the hull


any suggestion to fix this and remove the trim ring would be awesome!!

[smokeysevin]

Start by adding a shim/washer between the hull mounts and the plate at the rear to adjust the angle of the plate.

I ground the mounts for the plate down so the front of the plate was flush or slightly recessed when compared to the hull. I typically tuck the plate up by about the thickness of a quarter where possible. Then you can shim it back to adjust how the boat rides.

For the grates, I only ever tested the stock grate with the center bar removed and a cut back r&d grate. I didn't have porpoising with either. Before I cut the r&d grate, it scrubbed speed really bad and loaded up in the corners, 300ish rpms or so. I trimmed the wings back and slightly recessed the scoop and it made a big difference in the loading but stayed hooked really well still.

Sean

[dcuhpw]

Start by adding a shim/washer between the hull mounts and the plate at the rear to adjust the angle of the plate.

I ground the mounts for the plate down so the front of the plate was flush or slightly recessed when compared to the hull. I typically tuck the plate up by about the thickness of a quarter where possible. Then you can shim it back to adjust how the boat rides.

For the grates, I only ever tested the stock grate with the center bar removed and a cut back r&d grate. I didn't have porpoising with either. Before I cut the r&d grate, it scrubbed speed really bad and loaded up in the corners, 300ish rpms or so. I trimmed the wings back and slightly recessed the scoop and it made a big difference in the loading but stayed hooked really well still.

Sean

Ill give that a try. It may be my grate is causing some of the porpoising but it does stay hooked up well across the chop. Was about to remove the R&D plate and install the oem one but if I can get it to work right that would be nice. It “sinks” into the turns nicely which I’m sure is from the sponsons and ride plate combo. Reminds me of a T3 rxp hull but not as aggressive.

[TJS0712F]

I have a nozzle extension thread here somewhere. I also have a Zxi nozzle but never did create an actuator for it yet.

[dcuhpw]

I have a nozzle extension thread here somewhere. I also have a Zxi nozzle but never did create an actuator for it yet.

If you find it and can post the link here that would be great. It would be nice to keep these tech/mod threads together. Seems like they tend to die off without the op posting results. I’ll keep up with this one regarding what ends up working out. LOTS of tech is in the build threads but I haven’t found a good way to search for specific tech info.

[Spooling]

I have a nozzle extension thread here somewhere.

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http://greenhulk.net/forums/showthread.php?t=264089

[dcuhpw]

So I swapped on the factory plate and did a lot of tweaking. Mounting, testing, removing, repeat. I finally got the ride I was after. The ride now is smooth with zero porpoising. The oem plate is definitely slower than the R&D and the R&D does turn significantly better but this is a cruiser ski. Will be posting the R&D plate for sale if anyone wants it. And... it has the R&D reverse brackets and is compatible with the stock or aftermarket intake grate. Took me a heck of a lot of searching to find this thing.

Also want to give a shout out to Sean aka Smokeysevin for his help tuning the ride.