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View Full Version : What is best fin profile in hydros ?



majuri
03-02-2006, 01:55 PM
I like big deep sharp and thin ( 4 mm, 3/16 inch ) ?

will350
03-02-2006, 04:06 PM
I seen fins in about every shape and cuts. Rectangular,tapered,Simitar in different styles. Leading edge cut on the right side,cut on the left side or center cut. I know someone who "shims" the front of his and not to sraighten it up to the boat. Thinner is faster but too much flex isn't a good thing either.
I "bend" mine( bottom in toward the boat) about 10 degrees or shim them.
I feel like it makes them hold on a little better. I don't run them real deep when it'd fairly smooth but in rough turn conditions I get them down.
I think you have to "play" with them to get what you like.
Will

Mark75H
03-02-2006, 09:35 PM
I agree, I do not think there is one fin size, shape or angle that is best. Like props they have to be tuned to agree with the boat, motor, prop and driver

I like big, deep 150mm (6"), I am using 6mm (1/4")

My Pugh's fin bracket was set up tilted in a little less than 10 degrees or so. I made a jig to make it perfectly aligned with the boat ... screwed up the use of the fin ... had to put it back to 10 degrees tilted, duh.

Master Oil Racing Team
04-28-2006, 09:09 AM
We tried different fin arrangements according to the size of the course, the width of the turns and water conditions. We couldn't always remember what worked best on the different boats and different classes so we made a cardboard template for our fins. With the fin patterns, we could duplicate one for a new boat. The template had different fin positions. We we got a new hydro, I would cut the fin's trailing edge, fit it in the template, then stamp a position mark on the fin and number that position. The positon setting was read at the lower right hand corner of the fin mounting bracket. We entered the fin and setting in our test book to be able to duplicate the setting we liked best for the course we ran.

Joe Silvestri 36-S
04-28-2006, 09:14 AM
Wayne,

I've found that fin shape, width and depth below the sponson can be different for every different kind of boat. I currently use something like the first fin you posted on my CSH boats. I've raced three different kinds of boats in CSH and the depth of the fin has been the biggest difference between all three boats. If one boat floats high, I needed more fin and vise versa.

Master Oil Racing Team
04-28-2006, 10:26 AM
That's right Joe. If you notice the modified fin had another hole in order to raise it up for less depth in a course with tight turns, when the full size fin would have had too much surface area. Up like that, it wouldn't tilt. At Lakeland we ran the modified fin at around No. 8 or so. Every boat handles a little differently, even if it was made by the same manufacturer and the same time. Since we always traveled with the fin up, we came up with the standardization so it wouldn't take as long to dial the boat in at the race site.