cobra marty

Hey everyone, We all have some great ideas. So what are they? Post any new ideas or thoughts related to boats. I'll start;

Small adjustable trim tabs on the steps of stepped hulls. Would help get on plane and then retract up flat.

tomcat

Hydraulic Jacking Extension Box

I've mentioned this before and so have others. Seeing as how propshaft position is so important, and setting it high for speed compromises other things, why isn't there a hydraulic jacking extension box with about 4" of travel? I know a good setup man with a season of racing trial and error can get it right for most conditions, but I'd rather push a button and watch the speedo. Rather than fixing the drive at a compromise position, you could go 2" down for planing and cruising, and 2" up for speed.

Hydraulic Tunnel Extension Flap
(air flap on the bow, not tunnel tab at the stern)

We focus a lot on the design of the running surface in a cat, but the aerodynamics of the wing (the deck and tunnel roof) must be just as important at high speed. In T2x's history of cats, the idea of air flaps was proposed in the '60s. Was this ever done?

I picture a sliding flap that extends the deck, filling in the tunnel roof between the sponson tips, moving the center of lift forward slightly and increasing lift at lower speeds. Trim it back at higher speeds to reduce the need for negative trim on the drives. Once again a good setup man would have the boat balanced for known racing and load conditions, but I'd rather push a button. Even if it didn't work, it would be worth about 10 mph at the dock.

yahoo

The hydralic lift you are talking about has been done, The stainless marine boat had one on it at one time.

Something we talked about for supercat:


Using air cooled radiators to cool the motors.

No water pick ups on the hull 3-5 mph, constant running temp(lean out the motors), smaller water pumps(Nascar type) additional HP.

The weight was an issue, but Team Yahoo was already to light.

There were other ideas, just ran out of time.

Curtis

mama tryed

hey Cat ,ole bud,,,, I like your style!!

Ron P

I am suprized that more boats don't fee air to the steps. A step is supposed to airate the bottom, but where does it get the air? I believe Mr Technology was the first boat ever to have side inlets for a plenum of air to feed to the step. With out a way for air to fill in the void created by the step, it would actually create a vacuum. Think about it, kinda like an airplane wing. Now all Phantoms have holes on the side just above the chine, usually below the waterline.

Now I am seeing Fountain raceboats and every Outerlimits will air fed steps. It is worth a few extra miles per hour.

Next time you look at a step, see if there any holes drilled into it?

NASTY HABIT

what about some sort of forced air induction under the hull... more air less friction... ?? maybe thru the hull bottom..air inlets near the bow with jets downstream before the steps.....

Ron P

I believe there was one boat made by the name of Axiom that had a bottom like a knock hockey board (thousands of tiny holes drilled into the bottom) and a blower to generate air bubbles through the holes. Never heard about the boat after one article in Powerboat many years ago.

I believe that one hell of a blower would be needed to create positive air pressure in the system as the water rushed by at 80mph. Seems like a better idea to have the air sucked through the holes by the water.

NASTY HABIT

maybe it threw a belt...... down she goes...... that is the therory with steps correct.. ? creating a vaccum pulling air in the sides....the water pulling it under the hull.....

Ron P

I could never understand how air will be sucked sideways all the way to the keel as the boat is going 80 mph over the surface. Seems better to bring the air to where it is needed. Rather than have it fights it's way across the stream.

NASTY HABIT

considering the amount of hull actually making contact with the water at speed...it couldn't take much air to lubricatre whatever was making contact with the surface...depending on the surf conditions....