The Black Pearl LSH Spec Hydro 2019

[InspGadgt]

Definately...Starting at about 40mph it chines like crazy and right at the transition point between 44 and 45 mph it blows over. I'm trying all kinds of things to make it better but there are some design issues I think that during it's day was not a problem...but now that boats have so much more power they get amplified. I'm very slowly building another boat and watching the development of the latest BP so eventually I'll have a more competitive boat. Once that is finished maybe I'll try to address the bigger issues with the UL-1. That UL-19 outrigger thread is pretty inspiring for ideas.

As for the BP...did you fill the vents with something easily removable should it prove to not make a difference?

[longballlumber]

That boat is great for about 40mph. After that, it's a handful in race water. Definitely changed the world though. The motor and ESC gave FE a new life.

OK, back to trying to get some lift so we don't dig in the turns. I've filled the vents. We'll see what happens. I'm guessing it's not going to help much and I'm putting my $$$ on the angle of attack on the bottom face. 1 degree may just not be enough. We are definitely in rogue territory as most boats are 3-4 degrees.

Pete,

You really need to block out your riding surfaces! This will do 2 things;

1. break the surface tension between the water and the sponson surface
2. help to sharpen the ANY edge that water is releasing from. Those edges should be as sharp as possible!

these issues as well as dull turn fins and dull rudder blades can and will cause handling issues...


Just found this...

Coanda Effect: A moving stream of fluid in contact with a curved surface will tend to follow the curvature of the surface rather than continue traveling in a straight line.

To perform a simple demonstration of this effect, grab a spoon and find a sink. Get a small stream of water coming down from the sink, then place the bottom of the spoon next to the stream. Notice how the water curves along the surface of the spoon. If you hold the spoon so that it is free to swing, you should be able to notice that the spoon is actually being pulled towards the stream of water.

[Shooter]

So, does this only happen in Canada? :)

[TRUCKPULL]

So, does this only happen in Canada? :)

Coanda Effect:

https://en.wikipedia.org/wiki/Coandă_effect

Larry

[Shooter]

Does it only happen to Larry?

OK....all jokes aside, Mike usually busts my chops for giving up on boats too early. A prime example is him taking a boat that I deemed useless and setting a record with it. I'm trying not to give up on this boat too early. When we forced lift with the fin, it really did run great.

[jaike5]

Yes only to Larry!!
Our water is flat in Canada, unlike your water Pete! Don’t now why you guys get curved water ..... lmao �� just kidding!!
Cheers, Jay.

[Shooter]

Hi guys. Good news! I had my doubts, but filling in the oversized air bleeds really did the trick. The boat is turning very well now and no signs of hooking. I'll have to update the model with the changes.

https://youtu.be/85uHYLZqvSg

[longballlumber]

Looks good Pete! It will be interesting to see how it handles race water,

[Shooter]

Well, I managed to take a great running boat on Saturday and turn it into an absolute pig for Sunday’s race. Somehow I still took 2nd overall in a very competitive class, but it wasn't pretty. Ironically, the only time it DID run well was in the turns!! Go figure that one! So….. lesson learned….don’t blindly tweak a good running boat the night before a race! Eeeek!!!!

[Shooter]

OK, got the boat pretty much dialed in on Saturday. Smooth in the straights and scary fast through the turns. Need to make a few adjustments to the model with what we've learned over the past couple months.

1. Fill in bottom pockets to increase lift.
2. Make it more roomy by increasing tubwidth and possibly overall width, slightly.
3. Eliminate nose frame assy. Integrate into main stringers.
4. Sleeker sponson airfoil.

[TRUCKPULL]

OK, got the boat pretty much dialed in on Saturday. Smooth in the straights and scary fast through the turns. Need to make a few adjustments to the model with what we've learned over the past couple months.

1. Fill in bottom pockets to increase lift.
2. Make it more roomy by increasing tubwidth and possibly overall width, slightly.
3. Eliminate nose frame assy. Integrate into main stringers.
4. Sleeker sponson airfoil.

Pete
Are you going to increase the AOA?

Larry

[Shooter]

Hi Larry,

Here's the video of it running with the strut very close to neutral (center of prop shaft on center with bottom of ride pads). It is running very well. I didn't see a need to adjust the AOA, but I'm still open to ideas!! BTW, I was hoping to see you again at the cup. Sorry to hear that you aren't going to make it this year.

https://youtu.be/85uHYLZqvSg

[TRUCKPULL]

Hopefully my hand will be better before the Can AM race.

Larry

[detox]

Have you ever tried bending a little cup into the Octura m445. This prop really comes alive when done rite...and easy to do.

Turn fin shape is just as important as prop. Maybe a smaller, strait turnfin with no bend or very little bend inward.

Do your lipo packs appear puffy and hot after a full heat?

[Shooter]

Hey D! Good to hear from you!

No puffy packs here! I run (2) 5000mah packs. 8 laps, easy. The batts aren't even breaking a sweat. For the limited class, the motors are the limitation. That being said, I do tend to run more battery than most folks! I need the weight anyways, so it might as well be reserve power. Also, the voltage stays higher throughout the run.