80 MPH 21 hydro

[Preston_Hall]

A twin's top speed is slower most likely to the two props not being in pefect sync. When not timed EXACTLY then, yes, you are dragging a lot of stuff through the water.

Can't see strut, drive dog, or prop hub improvement since it isn't in the water. Maybe smaller cross sections but we need a stronger driveshaft.

Rudders - An extra water pickup to allow a flat blade has seemed to be, for the most part, an even trade. Now, use compressed nitogen to cool the engine an get rid of water pickups.

Turn fins - I have tried removing them all together along with seeing it on record boats. No substantial speed incease if any. Why? :unsure:

I think the hardware is almost a given. Myself, as many others, and proven again by Mr. Finch last weekend, it takes a certain size turn fin to keep the front of the boat in the turn. It takes a certain size rudder to intiate a good turn and keep the boat in the turn.

Let's narrower the focus here. If you could reduce the aero "drag" while keeping everything else the same, then less prop slippage=more speed with the same handling characteristics.

Here's a thought, how about not focusing on increasing SAW speed, but the turn speed. Without looking at the records I know the F oval hydro was at 99mph on bouy #1. If that speed could be maintained through the turn then the record would be 99 and not 72.

 

[Ron Zaker Jr]

faster than ever(2-3 mph gain

very interesting thoughts came up in my head reading this

but i just wanted to check one thing before i get into my maths

was it measured to be quicker or was the adrenalin flowing hard and

made the thought it was quicker?

68015[/snapback]

​

Tom,

It was quicker,no adrenalin rush.The boat actually drove better(much more free),the R's came up,and the roostertail laid down much closer to the water(we watched this for 4 laps). So I guess the question is,do we really need a "fullsize" sponson on the outside ? I tend to think we don't.

 

[Grimracer]

faster than ever(2-3 mph gain

very interesting thoughts came up in my head reading this

but i just wanted to check one thing before i get into my maths

was it measured to be quicker or was the adrenalin flowing hard and

made the thought it was quicker?

68015[/snapback]

​

Tom,

It was quicker,no adrenalin rush.The boat actually drove better(much more free),the R's came up,and the roostertail laid down much closer to the water(we watched this for 4 laps). So I guess the question is,do we really need a "fullsize" sponson on the outside ? I tend to think we don't.

68018[/snapback]

​

Ron good point and we have talked about this in the past. I still have that test sponson you made me.. heck let me take it out and try it this sat..

My concern with this is the lack of ballance in flight.

Pics and Vids if i can..

Grim

 

[Preston_Hall]

faster than ever(2-3 mph gain

very interesting thoughts came up in my head reading this

but i just wanted to check one thing before i get into my maths

was it measured to be quicker or was the adrenalin flowing hard and

made the thought it was quicker?

68015[/snapback]

​

Tom,

It was quicker,no adrenalin rush.The boat actually drove better(much more free),the R's came up,and the roostertail laid down much closer to the water(we watched this for 4 laps). So I guess the question is,do we really need a "fullsize" sponson on the outside ? I tend to think we don't.

68018[/snapback]

​

So the outward rear sponson must have been caarying the boat?

 

[Ron Zaker Jr]

faster than ever(2-3 mph gain

very interesting thoughts came up in my head reading this

but i just wanted to check one thing before i get into my maths

was it measured to be quicker or was the adrenalin flowing hard and

made the thought it was quicker?

68015[/snapback]

​

Tom,

It was quicker,no adrenalin rush.The boat actually drove better(much more free),the R's came up,and the roostertail laid down much closer to the water(we watched this for 4 laps). So I guess the question is,do we really need a "fullsize" sponson on the outside ? I tend to think we don't.

68018[/snapback]

​

So the outward rear sponson must have been caarying the boat?

68021[/snapback]

​

Preston,

We "think" that was the case along with the turn fin working correctly in the turns, and decent speed (around 60 on that boat at that time) Again he could not let off.

 

[Ron Zaker Jr]

faster than ever(2-3 mph gain

very interesting thoughts came up in my head reading this

but i just wanted to check one thing before i get into my maths

was it measured to be quicker or was the adrenalin flowing hard and

made the thought it was quicker?

68015[/snapback]

​

Tom,

It was quicker,no adrenalin rush.The boat actually drove better(much more free),the R's came up,and the roostertail laid down much closer to the water(we watched this for 4 laps). So I guess the question is,do we really need a "fullsize" sponson on the outside ? I tend to think we don't.

68018[/snapback]

​

Ron good point and we have talked about this in the past. I still have that test sponson you made me.. heck let me take it out and try it this sat..

My concern with this is the lack of ballance in flight.

Pics and Vids if i can..

Grim

68020[/snapback]

​

Mike TRY IT,it will either sink or swim,get a healthy launch.

 

[Preston_Hall]

faster than ever(2-3 mph gain

very interesting thoughts came up in my head reading this

but i just wanted to check one thing before i get into my maths

was it measured to be quicker or was the adrenalin flowing hard and

made the thought it was quicker?

68015[/snapback]

​

Tom,

It was quicker,no adrenalin rush.The boat actually drove better(much more free),the R's came up,and the roostertail laid down much closer to the water(we watched this for 4 laps). So I guess the question is,do we really need a "fullsize" sponson on the outside ? I tend to think we don't.

68018[/snapback]

​

So the outward rear sponson must have been caarying the boat?

68021[/snapback]

​

Preston,

We "think" that was the case along with the turn fin working correctly in the turns, and decent speed (around 60 on that boat at that time) Again he could not let off.

68022[/snapback]

​

Ok. let's go a little further. Obviuosly there needs to be an outside sponson. How about a narrow sponson mounted to the tub with no boom tubes.

 

[Ron Zaker Jr]

faster than ever(2-3 mph gain

very interesting thoughts came up in my head reading this

but i just wanted to check one thing before i get into my maths

was it measured to be quicker or was the adrenalin flowing hard and

made the thought it was quicker?

68015[/snapback]

​

Tom,

It was quicker,no adrenalin rush.The boat actually drove better(much more free),the R's came up,and the roostertail laid down much closer to the water(we watched this for 4 laps). So I guess the question is,do we really need a "fullsize" sponson on the outside ? I tend to think we don't.

68018[/snapback]

​

So the outward rear sponson must have been caarying the boat?

68021[/snapback]

​

Preston,

We "think" that was the case along with the turn fin working correctly in the turns, and decent speed (around 60 on that boat at that time) Again he could not let off.

68022[/snapback]

​

Ok. let's go a little further. Obviuosly there needs to be an outside sponson. How about a narrow sponson mounted to the tub with no boom tubes.

68025[/snapback]

​

Preston,

I am concerned about launching.I have tried little ski like outside sponsons on normal booms and spacings,and the launch is "ify". Mike is testing something a little different ,we'll see what happens. I keep thinking about control line speed racers,they are very a-symetrical.

 

[Speedway]

What about a Carbon Fiber Hydo-foil? No weight and can carry a load 4000 times its weiagh If tuned.

faster than ever(2-3 mph gain

very interesting thoughts came up in my head reading this

but i just wanted to check one thing before i get into my maths

was it measured to be quicker or was the adrenalin flowing hard and

made the thought it was quicker?

68015[/snapback]

​

Tom,

It was quicker,no adrenalin rush.The boat actually drove better(much more free),the R's came up,and the roostertail laid down much closer to the water(we watched this for 4 laps). So I guess the question is,do we really need a "fullsize" sponson on the outside ? I tend to think we don't.

68018[/snapback]

​

So the outward rear sponson must have been caarying the boat?

68021[/snapback]

​

Preston,

We "think" that was the case along with the turn fin working correctly in the turns, and decent speed (around 60 on that boat at that time) Again he could not let off.

68022[/snapback]

​

Ok. let's go a little further. Obviuosly there needs to be an outside sponson. How about a narrow sponson mounted to the tub with no boom tubes.

68025[/snapback]

​

Preston,

I am concerned about launching.I have tried little ski like outside sponsons on normal booms and spacings,and the launch is "ify". Mike is testing something a little different ,we'll see what happens. I keep thinking about control line speed racers,they are very a-symetrical.

68026[/snapback]

​

 

[Ron Zaker Jr]

What about a Carbon Fiber Hydo-foil?  No weight and can carry a load 4000 times its weiagh If tuned. 

faster than ever(2-3 mph gain

very interesting thoughts came up in my head reading this

but i just wanted to check one thing before i get into my maths

was it measured to be quicker or was the adrenalin flowing hard and

made the thought it was quicker?

68015[/snapback]

​

Tom,

It was quicker,no adrenalin rush.The boat actually drove better(much more free),the R's came up,and the roostertail laid down much closer to the water(we watched this for 4 laps). So I guess the question is,do we really need a "fullsize" sponson on the outside ? I tend to think we don't.

68018[/snapback]

​

So the outward rear sponson must have been caarying the boat?

68021[/snapback]

​

Preston,

We "think" that was the case along with the turn fin working correctly in the turns, and decent speed (around 60 on that boat at that time) Again he could not let off.

68022[/snapback]

​

Ok. let's go a little further. Obviuosly there needs to be an outside sponson. How about a narrow sponson mounted to the tub with no boom tubes.

68025[/snapback]

​

Preston,

I am concerned about launching.I have tried little ski like outside sponsons on normal booms and spacings,and the launch is "ify". Mike is testing something a little different ,we'll see what happens. I keep thinking about control line speed racers,they are very a-symetrical.

68026[/snapback]

​

68028[/snapback]

​

Speedway,

Please explain

 

[Speedway]

Ok, A Hydro-foil is basically a wing that uses Water as a medium for lift as opposed to Air. Same principal that the water rushing over the swept surface creates Lift. The Hydofoils can carry immense loads while creating low drag and weigh benefits. Come to think of it, They could also be used as steering implememts. The drag that IS created by these is so insignificant, Its all but eliminated. By Calculations; A foil for a rigger (2 i guess) would need a lift area of 2-3 squared inches and would weigh in total for both less that 10 grams. Thats for a full size 2 motor rigger

http://www.hydrofoiling.de/shop/ss_pro.jpg

http://images.google.ca/images?q=tbn:5Pw-A...r/hydrofoil.jpg

http://mss.scdsb.on.ca/Water%20Strider/hydrofoil.jpg

 

[Grimracer]

Can you say TURTLE...

OUCH..

This needs to be looked at.. thinking about it it looks like a gyro would be needed to manage the AOA

COOL IDEA..

Grim

 

[Ron Zaker Jr]

Ok,  A Hydro-foil is basically a wing that uses Water as a medium for lift as opposed to Air.  Same principal that the water rushing over the swept surface creates Lift.    The Hydofoils can carry immense loads while creating low drag and weigh benefits.  Come to think of it,  They could also be used as steering implememts.    The drag that IS created by these is so insignificant,  Its all but eliminated.  By Calculations;  A foil for a rigger (2 i guess) would need a lift area of 2-3 squared inches and would weigh in total for both less that 10 grams.  Thats for a full size 2 motor rigger 
http://www.hydrofoiling.de/shop/ss_pro.jpg

http://images.google.ca/images?q=tbn:5Pw-A...r/hydrofoil.jpg

http://mss.scdsb.on.ca/Water%20Strider/hydrofoil.jpg

68031[/snapback]

​

Very wild,Iget it.

 

[Slideblues]

Check this one out, Pics of a R/C version too.........

http://www.hydrofoil.com/gallery.htm

 

[Preston_Hall]

Hydrofoils................hmmmmmmmmmmm

I don't know about cornering but the SAW should be good. Since the foil is under water then the attitude of the boat will remain constant. The foils would also act as a rudder and turn fin which would eliminate these two items from current designs. But are they efficient? I mean, you don't see them widely used.

It shouldn't be to much trouble to attach a set to the bottom of a tub. But it seems as though the intial drag would be too much for us to overcome. In comes the 2 speed transmission?

I have always liked the transmission idea. If you have never seen what they use in the cars then you should. There is nothing to it.

 

[Slideblues]

Seems like there is a club in Germany that runs R/C Hydrofoils, cant remember for sure, Maybe some of our Euro friends can chime in with more info,

Gene

 

[Speedway]

They arent widly used Commercialy (for Cost an NRE's) but from a personal consumer standpoint, It's growing. They have peddle powered hydro-canoes that go 20 Mph! The figures have a Foil as being well over 1700 percent more efficient than a "V" type hull. They are actually easy as all hell to make ! Maybe just a Foil or 2 on the front of a rigger to achieve a nice angle and have the back push? Just a thaught

Hydrofoils................hmmmmmmmmmmm
I don't know about cornering but the SAW should be good. Since the foil is under water then the attitude of the boat will remain constant. The foils would also act as a rudder and turn fin which would eliminate these two items from current designs. But are they efficient? I mean, you don't see them widely used.

It shouldn't be to much trouble to attach a set to the bottom of a tub. But it seems as though the intial drag would be too much for us to overcome. In comes the 2 speed transmission?

I have  always liked the transmission idea. If you have never seen what they use in the cars then you should. There is nothing to it.

68047[/snapback]

​

 

[Glenn Quarles]

Hey guys, back to the part of the thread talking about streamlining the booms. Here are my best guesses, I know round booms are VERY draggy (is that a word?) and that changing their shape a little can cut down on their drag a lot. BUT I don't know how much the boom drag adds to the overall drag of the boat...I have to leave that to the guys with more sophisticated testing equipment than I have to figure out. My take on the pros VS cons is that they are easy to fix, don't make the boat do anything weird and may give another mph. Back in the mid 90's I figured out a way to streamline them that is simple and light (you know how anal I am about weight) and have done it on every SAW boat since.

I simply use a piece of balsa trailing edge stock (cut the width down so the thick part is the same as the dia of the booms) and thin heat shrink tubing like is used on battery packs and heil blades.

The fairings (I don't call them wings because they are not there to provide lift) are very easy to set where you want them. I set them straight, but even if they get moved they just set themselves in position when the boat gets moving fast enough. I have used tape to hold them in one position or another, but haven't really noticed they affect the boat to much.

I have four pictures that I will try to post to help show what I mean.

Glenn

 

[Glenn Quarles]

Here is the next picture of our .12 boat. Notice the weight of the boat in the background.

Glenn

 

[Glenn Quarles]

Here is the next picture of our .12 boat. Notice the weight of the boat in the background.

Glenn