How wide should the sponson ride pads be

[Jim Caldwell]

on a 70 mph 18 to 20 pound sport hydro???

 

[FloridaScaleBoater]

on a 70 mph 18 to 20 pound sport hydro???

Is this a gas sport hydro?

Could you be a little more specific? Scratch built, production hull, size of hull,

Already built boat? Is CG where it should be?

 

[Terry Keeley]

on a 70 mph 18 to 20 pound sport hydro???

How much air you gonna trap underneath?

 

[Jim Caldwell]

It's fine at that speed ,except when i hit a 2"wake and it pulled the turn fin side while going straight and flipped.

It currently has almost 4" ride pads.

 

[Hydro Junkie]

I have to agree with Rick, more information would help you get good information as your posts so far give us nothing to go on other than the boat's weight and approximate speed. The size of the boat, including tunnel width would help out considerably

 

[Jim Caldwell]

39 3/4" x 22" with a 12" tunnel, again it is fine at 70 mph( Eagletree data logger with 10mhz GPS) and it corners great.

The problem appears to be the sponson surface area when it hits a wake.

What is the ride pad wideth on a gas sport hydro??

 

[Terry Keeley]

It's fine at that speed ,except when i hit a 2"wake and it pulled the turn fin side while going straight and flipped.

It currently has almost 4" ride pads.

Don't quite understand, "it pulled the turn fin side".

Whatchu talkin' 'bout Willis?

 

[Dasboatman]

Hey Jim,

You are asking for help, and providing little useful information. The sponson bottom on my 49" 20 pound Classic Thunderboat is 4 inches but that's only a small part of the hull design. Have you considered sponson angle, sponson depth, height of the center section nose above the water, and a few other items. Could your turn fin be tucked under so much that it's acting as a hydrofoil when it is at a negative angle causing the bow to stuff and the hull tumble down the lake. Under any circumstance, this isn't fine.

Rick and Terry would be more than happy to help you but without data, they would only be guessing. Pics similar to these would give us a much needed clue. CHEERS !!! Bob

 

[Jim Caldwell]

Thanks guys, I have found my answer on another fourm.

 

[brad nichols]

And the answer was????

 

[Jim Caldwell]

2.5" to 3.25 at this weight and speed. So I will cut them down form 4.00" to 3.25 to start with 3.5 AOA and we will see.