Pad help for Dateline Bikini (Similar to Sidewinder 16 )

[spybot]

Hii guys I have 1980 Datelin Bikini a copy of the super 16 sidewinder.
I have seen the pad design on the web see the attached pics.
I need help in getting the design details of this pad and or how can i get the formula for building a pad like this.
at present when i hit around 40 i get really bad chine walk. Hopefully this pad will sort this out.
I am also considering adding a jack plate to the 85hp i have on the back. the engine will be rebuild hopefully to 15 spec as far as im aware they are the same block and heads but with diffrent carbs and some sort of filler block on the crankshaft. I will even consider porting the engine if i could some help modding this that would be great.

 

[CrazyFinn]

I would build a flat pad on the bottom, with sharp vertical sides to meet the existing bottom (or maybe even slanted in very slightly at the top). Make the edges as sharp as you can, and extend the pad slightly beyond the transom - taper the top "forward" to meet the transom. Make it least an inch high at the sides, where it meets the hull. Build it up with glass - if needs to be thicker, you might want to core it with some wood. Takes a bit of courage to carve up the bottom of a perfectly good boat, but if you want more speed...

A flat pad will give you more lift at top speed, and therefore a higher top speed. You want the boat completely out of the water, just the last few inches of the pad skimming on the surface. The boat is easier to push through the air than it is through the water... Kinda like skipping a flat stone across the water. The sharp edges reduce drag. A Vee pad rides smoother, is a bit more forgiving, but doesn't go as fast.

The sharp, slightly angled sides on the pad will give you better cornering - less likely for the back end to skip out on a hard corner (it actually "digs in" on corners).

This is what we did in our racing days running Critchfields, VooDoo's and other smaller V-bottoms before we switched to tunnel hulls. It makes a big difference.

 

[spybot]

Hey CrazyFinn i will take all this on board. How far beyond the transom should i take it ? Maybe an inch or so ??
I think i get how you mean by tapering the top forward like the feathers on an arrow ?? Sort of at an angle going into the transom ?