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Thread: The Black Pearl LSH Spec Hydro 2019

  1. #151
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    Sorry for the delay guys. Yes, the endbell heat sink is a custom job. It slip fits onto the endbell thereby making it legal. You are correct. The 90° outlets will cause more restriction than straight. I use the ones with the largest internal flowpaths that I can find. There are some out there (banjo type, adjustable angle) that are terrible. They restrict the flow considerably. Yes, the spiral internal cooling can is the way to go IMO. There are a few people that I know of working on them.

    As for the boat, I ran it again last weekend. It's fast, but I still need to get the steering figured out. The turn fin was angled upwards towards the front of the boat (counterclockwise if looking at the fin). It didn't dawn on me until I was halfway home from the pond. Good thing is that the boat showed no signs of blowover, and the speeds seem to be pretty good. The low AOA and aggressive airfoil in the front make it hard to get up on the plane. You have to ease it a bit. Still need to get a GPS on it. Here's the video that Tyler took on Todd's camera:

    https://www.youtube.com/watch?v=jfiR...ature=youtu.be

  2. #152
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    Man I wish our water was that calm!

  3. #153
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    It was a pretty nice day!! :) I'll never forget the day Ball ran in 25mph winds out there. There were white caps!! Naturally, his boat ran just fine.

  4. #154
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    Hi everyone. Had another chance to run the spec version over the weekend. I adjusted the fin as mentioned above. No bananas. Tried everything. New fin, fin inside, fin outside. It still hooked badly in the turns.

    Then, for the last run, I tried something completely out of the box. I turned the fin all the way forward (counterclockwise) to intentionally lift the boat (see photo). Ridiculous and hard to believe, but it zipped around the turn like nobodies business. Like a dog gone boomerang. It was beautiful to watch (naturally, there are no videos of that run). Speeds were 54mph on the GPS w/H5 and Aquacraft 2030.

    So, it would seem that it's loosing lift in the turns and burying the sponson. Pitching the fin corrected it, but obviously not the way I want to run.

    Possible solutions:

    1. Run a prop without as much lift (maybe one of the newer ABC's)
    2. Plug the vents. They work great in the straights, but may be causing the boat to lose lift in the turns.
    3. Pitch rudder inwards (under hull) to possibly lift front of boat in the turn.

    Any ideas?
    Attached Images Attached Images

  5. #155
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    54mph? Nice! Was that 4 cell?

  6. #156
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    Quote Originally Posted by Shooter View Post
    Hi everyone. Had another chance to run the spec version over the weekend. I adjusted the fin as mentioned above. No bananas. Tried everything. New fin, fin inside, fin outside. It still hooked badly in the turns.

    Then, for the last run, I tried something completely out of the box. I turned the fin all the way forward (counterclockwise) to intentionally lift the boat (see photo). Ridiculous and hard to believe, but it zipped around the turn like nobodies business. Like a dog gone boomerang. It was beautiful to watch (naturally, there are no videos of that run). Speeds were 54mph on the GPS w/H5 and Aquacraft 2030.

    So, it would seem that it's loosing lift in the turns and burying the sponson. Pitching the fin corrected it, but obviously not the way I want to run.

    Possible solutions:

    1. Run a prop without as much lift (maybe one of the newer ABC's)
    2. Plug the vents. They work great in the straights, but may be causing the boat to lose lift in the turns.
    3. Pitch rudder inwards (under hull) to possibly lift front of boat in the turn.

    Any ideas?
    Looking at the pic closely...with my very limited experience with boats but a lot of experience racing RC cars...it looks to me like you have a lot of downward taper between the sponsons...is it fully symmetrical underneath with the same but opposite taper underneath? You might be generating too much down force between the sponsons. Unfortunately that would be quite a redesign...but if you can get away with less down force you'll have less aerodynamic drag and could possibly lead to an even faster boat.

  7. #157
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    We've been looking at it a bunch. We're thinking the underside doesn't have enough angle to pack. It runs okay but not okay enough. We're just not there yet.

    We'll have to get a vid of my stealth running so you guys can see what we mean by packing. That thing is disturbing but predictable.
    Noisy person

  8. #158
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    Quote Originally Posted by Shooter View Post
    Hi everyone. Had another chance to run the spec version over the weekend. I adjusted the fin as mentioned above. No bananas. Tried everything. New fin, fin inside, fin outside. It still hooked badly in the turns.

    Then, for the last run, I tried something completely out of the box. I turned the fin all the way forward (counterclockwise) to intentionally lift the boat (see photo). Ridiculous and hard to believe, but it zipped around the turn like nobodies business. Like a dog gone boomerang. It was beautiful to watch (naturally, there are no videos of that run). Speeds were 54mph on the GPS w/H5 and Aquacraft 2030.

    So, it would seem that it's loosing lift in the turns and burying the sponson. Pitching the fin corrected it, but obviously not the way I want to run.

    Possible solutions:

    1. Run a prop without as much lift (maybe one of the newer ABC's)
    2. Plug the vents. They work great in the straights, but may be causing the boat to lose lift in the turns.
    3. Pitch rudder inwards (under hull) to possibly lift front of boat in the turn.

    Any ideas?
    Something I learned a long time ago about mounting turn fins.
    Always mount the fin on the inside of the bracket.
    When it is on the outside, in a hard turn the water coming up the fin, hits the bracket and is trying to lift the sponson.

    If your bracket is 1/8" thick, you are then loosing about 25% of your fins capability to hold the sponson down.

    Larry
    Past NAMBA- P Mono -1 Mile Race Record holder
    Past NAMBA- P Sport -1 Mile Race Record holder
    Bump & Grind Racing Props -We Like Em Smooth & Wet

  9. #159
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    Inspector - You are spot on with the comments regarding down force. It works well in the straights, but then too well in the turns. BTW, I am told that 54mph is no longer a good speed for LSH. Whaaaaaaaaaaattttt???? I still think it's decent. :) Not everyone can be doing 116mph like Mike ball! :)

    Terry - I would have stopped at 'disturbing'. Only the prop in the water, with an occasional touch and go...just to remind you that it is still a boat that you are driving. Simply amazing. I've tried setting boats up like that, but they just nose dive when they come back down.

    Larry - 100% agree. I usually run the fin on the inside so the water spray doesn't hit the bracket and give it more lift. But for this experiment I was intentionally using the fin to lift the boat.

  10. #160
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    Not trying to stir the pot, but I have been running my turn fins on the outside of the bracket since I started racing sport boats and I never experienced issues with turn fin spray hitting the bracket affecting boat lift. I would go out on a limb and suggest my boats carry more speed thru the turns than most... just my 2 pennies.

  11. #161
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    Well, proof is in the pudding! Anyone that's seen Mike's old LSH whip around a turn can attest to this. Looks like I'll be leaving mine on the outside for good!

  12. #162
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    Both Tyler and I have the fin on the outside. I can't say I know why it works. On his Pearl it was on the inside.
    Last edited by T.S.Davis; 05-23-2019 at 01:45 PM.
    Noisy person

  13. #163
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    Back when I was told about this trick, we were running round cells in our Sport Hydro's.
    So our speeds were a lot lower back then.
    For me now it is just something that I always do.

    Larry
    Past NAMBA- P Mono -1 Mile Race Record holder
    Past NAMBA- P Sport -1 Mile Race Record holder
    Bump & Grind Racing Props -We Like Em Smooth & Wet

  14. #164
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    I'll have to give that a try on my UL-1 and see if it calms that thing down...For the life of me I can't get that boat dialed in at a decent speed.

  15. #165
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    Quote Originally Posted by InspGadgt View Post
    I'll have to give that a try on my UL-1 and see if it calms that thing down...For the life of me I can't get that boat dialed in at a decent speed.
    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.
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  16. #166
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    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?

  17. #167
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    Quote Originally Posted by Shooter View Post
    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.
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  18. #168
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    So, does this only happen in Canada? :)

  19. #169
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    Quote Originally Posted by Shooter View Post
    So, does this only happen in Canada? :)
    Coanda Effect:
    https://en.wikipedia.org/wiki/Coandă_effect


    Larry
    Past NAMBA- P Mono -1 Mile Race Record holder
    Past NAMBA- P Sport -1 Mile Race Record holder
    Bump & Grind Racing Props -We Like Em Smooth & Wet

  20. #170
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    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.

  21. #171
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    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.

  22. #172
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    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

  23. #173
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    Looks good Pete! It will be interesting to see how it handles race water,

  24. #174
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    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!!!!

  25. #175
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    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.

  26. #176
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    Quote Originally Posted by Shooter View Post
    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
    Past NAMBA- P Mono -1 Mile Race Record holder
    Past NAMBA- P Sport -1 Mile Race Record holder
    Bump & Grind Racing Props -We Like Em Smooth & Wet

  27. #177
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    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

  28. #178
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    Hopefully my hand will be better before the Can AM race.

    Larry
    Past NAMBA- P Mono -1 Mile Race Record holder
    Past NAMBA- P Sport -1 Mile Race Record holder
    Bump & Grind Racing Props -We Like Em Smooth & Wet

  29. #179
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    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?

  30. #180
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    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.

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