The Black Pearl LSH Spec Hydro 2019

[Shooter]

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=jfiRiT3hVrs&feature=youtu.be

[InspGadgt]

Man I wish our water was that calm!

[Shooter]

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.

[Shooter]

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?

[InspGadgt]

54mph? Nice! Was that 4 cell?

[InspGadgt]

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.

[T.S.Davis]

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.

[TRUCKPULL]

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

[Shooter]

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.

[longballlumber]

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.

[Shooter]

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!

[T.S.Davis]

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.

[TRUCKPULL]

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

[InspGadgt]

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.

[Shooter]

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.