hull sucking to water

[Gary]

I have a question on my Phil Thomas 45. When I start a SAW run the left front sponson, looking from the front, is pulling up pretty good off the water where I have to slowly let up the throttle and wait for it to "suck" itself to the water. This happens from 50-55 up to 65-70 and then when she settles down perfect runs to mid 90's with no problem.This entire run/ proccess will happen very quickly and I have mastered it pretty well with no blow overs. So what is actually happening when it's sucing itself to the water? Its almost like a vacuum is taking place with the hull and water but I dont understand how that will happen. As soon as that sponson is planted though it will not come up again. Any thoughts?

[detox]

With counterclockwise rotating props, usually it is the lefthand sponson lifting during hard throttle. You say it is the right hand sponson. Are you using a curved fin or strait fin? It seems a small strait fin (no lift) would work best.

Maybe the right side sponson needs more weight added.

Maybe stern is lifting more at higher rpm causing AOA of sponson to be less. Less aoa will stick better.

I have never made a SAW run in my life?


...

[Gary]

Its the left side looking from the front. There is no turn fin. Just trying to figure out the "sucking" sensation that takes place.

[antslake]

You should use the terms port and starboard when refering to left and right parts of a boat, just sayin.

[Rumdog]

Aerodynamics.

[Jesse J]

Have you blue printed the sponsons?

[carlcisneros]

can you please provide the following:

Strut depth from the bottom of the hull to the bottom of the shaft.
Angle of the shaft (if possible)
Rudder location. (left or right side of the boat, looking from the rear)
do yo uhave to hold LEFT rudder in it to make it go straight?

these are needed to figure out why your boat is doing what it is.

and you said yo uare not using a turn fin, correct?

[Gary]

My question may have come across wrong. I have no problem with the hull, It performs very well and the speeds are close to 100 on the gps. http://www.youtube.com/watch?v=mvi9KIth-kg My question is why do Hydros suck themselves to the water like they do.... almost like a vaccuum effect, which is why they can go so fast aswell.

[carlcisneros]

alot has to do with BOTH Aerodynamics and Hydrodynamics.
but most importantly is the time and care of setting the boat up correctly.

each and every hull (even if it is the SAME hull) has it's own characteristics and
has to be set up as such.

it is a long process to set oneup properly, but the end results are worth it big time.

[Old Vetter]

That is awesome. I would love to have a boat that ran that well. Do you get teased a lot from your fellow racers on how you hold your transmitter?

[Gary]

LOL I have no idea how I came to holding the transmitter backwards like that but I have always done it.....steer with the left and throttle with the right, and I am right handed.

[detox]

That water is glass smooth. More angle of attack on sponsons will make boat faster and stick less.

[Rumdog]

Yeah, but with more AOA, once it starts walking, it aint gonna stop. Plus it will be more sensitive to changes in water condition.

[nobbiworld]

Hi Gary, if you don't mind, what voltage and motor are you running. Love the video, well done. Steve

[Gary]

1527.5y and 2- 18.5 volt 5,000- 65c-130c Thunder Power batteries in parallell. Thanks for the coment. The next video,soon, will be closer and a little faster.............with NO sun glare LOL !