Sport hull blowoffs

[Scott Schneider]

I am suffering from random Blowoffs of my large gas sport hydro.

All was well upto @65mph, but now at 68/70 boat runs really nice on the water, then out of the blue it KITES !!

Strut & prop adjustments have cured this, but at a cost to speed & overall handling <_<

****

My Question ?

Inside sponson edge "Air fences" ... Basicly thin vertical strips that are attached to nose of boat on sponsons inside edges, and go back onto top deck to @ boats CG. Their height @ 3/4 to 1" above decking.

Idea is to keep air that starts between sponsons and get split with some going under hull, some over .... So air that go's over the top decking is getting held from spilling outward by the Fences. (creating higher downforce)

Seen them years ago on boats & run them myself on .21 sport hulls, but don't see them being used much ??

Is this a valid trick to get more downforce without screwing with the optimum strut/prop combo ?

Actuall photo of Air fences here: http://p086.ezboard.com/fjimsrcboatdockjim...cID=22360.topic

Thanks.

Scott

 

[Mark Anderson]

They very well could do the trick for you. They hold the air on the deck. Temporarily attach them and give it a try.

 

[Dennis Whitt]

How about making some simple canards to mount on the front booms.A couple of pieces of lexan and 4 nose wheel clamps would make some adjustable canards.That would pull some of the air from the bottom and redirect the air over the boat.

 

[SayMikey]

How about making some simple canards to mount on the front booms.A couple of pieces of lexan and 4 nose wheel clamps would make some adjustable canards.That would pull some of the air from the bottom and redirect the air over the boat.

PUT A PIECE OF RADIO BOX TAPE ABOUT 2 INCHES LONG AT THE BASE OF THE RUDDER HANGING OFF THE BACK ABOUT 1-1/2 INCHES. IF THAT CURES IT GET A LONGER RUDDER

 

[Brian Blazer]

In my opinion, there are three major things that contribute to blow offs:

1. Too much angle of attack

2. Too much air compression

3. Too wide of sponsons.

Brian