So I'm watching the OPA race this past weekend and I notice that most of the big boys that are running #6 drives all have this tube that starts right above the prop, through the drive and up above out of the water. Does anyone know what that's for? I assume it's specific to surface drives but I just haven't seen it on any other type of setups and can't really think of how that would benefit these guys. Anyone want to school me on what this is used for?

As I recall, it's used to ventilate the prop to help them get the RPM's up to come up on plane better.

YUP,

you got it, you cant believe how many times I have been asked this same question in the pits, but then again, I was one of the askers many years ago

So it's really used to help the whole shot when the green flag drops or is it something that all surface drives would benefit from?

They're there to help the boat get up on plane. Alot of surface drives have them, #6's, Arnesons ect....

It is utilized for less horse power but bigger boats. It allows the props to aerate a bit and spin more freely. I rigged a 377 Talon with 525EFI's with 6 drives. Boat was very slow to plane 25-30 seconds. Installed the aerator's, planing time is half now.

I see a lot of boats that just use rubber tubes that are hose clamped on, and then you see Fountain that uses nice chrome tubes... The chrome tubes look way more badass... and finished.

yes, no and kind of.....

The tube in question is known as an airation tube. It allows the propeller to suck air from the surface which causes the prop to lose its "bite" in the water and slip. This allows the engine to rev up into its torque curve and roll the boat over onto plane without lugging.

Most of the big HP surface drive boats turn very big props meant to run with barely half a prop in the water. It takes big torque to turn them when fully submerged ( off plane ) "Airating" the props takes a large amount of load off the drivetrain when the props are still fully submerged.

Think of it as slipping the clutch to take off in a standard trans car in 5th gear. Once your rolling along at highway speed, the car has plenty of power to accelerrate.

You mean like this?



This is one I did on my old black hawk drive. It allowed a stock 500efi to plane off with twin 31 pitch props. Without the airation tube, the boat would not plane with anymore than two passengers and NO fuel load. With it, planing with full fuel and 6 onboard was easy.

It's a special holder for a purpose built NOS bottle which aides in propeller aquaspectamonix.