I'm undecided on this topic at the moment.
I have damage to the fins on my intake currently and was planning on replacing the complete intake housing. I do know that with one fin mostly missing and the other with a chunk out of it my boat cavatates bad when turning left (I have a hard time turning right being an old circle track racer ;) ). My boat does not have a forward turning fin currently so I don't know how that would affect things at this point.
Maybe when I'm ready to replace the intake housing I'll cut both fins off completely and go out for a test then try the same run with a new intake. Gonna be a little while before I get to it though.
I also would like to see some opinions.
So, what do you think?
Anyone cut them off and had it be BAD????
Seems like there are some mixed reviews. I have no practical experience to back this, but it seems to me that the pivoting axis would be well forward of the intake. Just imagine driving your boat into a turn and feel where the boat is "grabbing" and pivoting around. I think it's somewhere near the front seats, which would make sense. The pivot point should be where the turn skags are mounted, right?? Otherwise, the skags would be fighting the natural tendency of the hull in a turn. The boat would still want to turn where it does, and the skags would have to slide sideways or see a lateral movement. Kind of like turning a tight turn with a tandem trailer. The forward tire becomes the axis and the rear tire "slides" throught the turn.
There are 2 aspects being talked about. One is pump loading and the other is handling. I can see the benefit in tight turns where the skag could interfere with pump loading, and it sounds like some have had good luck removing them. Would be cool to see the results with and without the skags with an intake pressure gauge with back to back runs.
I still think the boat needs to have something in the rear to keep it from grabbing the skag and sliding out completely throught the turn into a spiin. Maybe just a nozzle rudder?? Somebody said it got very squirley when they removed them and that was with a small block. Very good thread, I've always wondered what would happen if they were removed, just never got the balls to crawl under the boat with a sawzaw ;D ;D ;D ;D
the pivot point moves at different speeds and different centers of gravity,
Think of your hull as a giant, blunt weird shaped fin.
Ive been thinking about this (never a good thing) and looking at the thread about rudders. On my boat the rudder made no difference, and I always thought it was because of the fins on the intake. In my way of thinking ( :screwy:) the hull should want to go straight (with no outside influences) and the intake fins will do the same. But the rudder (or thrust from the pump) needs to slide the back of the hull around to turn it (right/wrong ?) . So the fins and rudder are fighting each other, one trying to go straight and one trying to turn :-\.
I also remember there has been a boat at the circle races that used a fixed nozzle and a big V-drive style rudder. Does anyone know if that boat had fins on the intake ?
What I would realy like to know is do the intake fins realy do anything for the pump (loading) in a straight line. I do remember an old thread somewhere that the old circle boats would cut the outside fin off to help load the pump in the turns.
It just dosnt make sence to have two sets of fins (one beeing the rudder) that close together trying to do different things ??? . I cant imagine a boat other than a jet adding a fin in that location and expecting the boat to turn. But maybe I'm just looking at it wrong (wouldnt be the first time). ;D