JD's New Turn fin set up

[Mike Hughes]

JD like how well my 1/10 91 winston was turning in the corners. He asked for one of my turn fins. Just finish it up today.

 

[user 21992]

Mike, that's an awesome idea, and like the install !! I don't know anything about 1/10 scale, and have to ask, why is the turn fin mount on the left sponson. Do you race counter clockwise, making left turns ??

 

[Mike Hughes]

Mike, that's an awesome idea, and like the install !! I don't know anything about 1/10 scale, and have to ask, why is the turn fin mount on the left sponson. Do you race counter clockwise, making left turns ??

YES

 

[SayMikey]

Is that a 17 degree bend?

 

[Duke Mordja]

Mike,

Does the turnbuckle support provide noticeable change to turning characteristics? I would assume yes - otherwise no need for it.

What would expectations be if added to a boat that turns well (well enough for me) already?

 

[DON MAHER]

Just an small but important point you may consider. The way the fin is mounted to the bracket will cause lift when the water comes up and contacts the bottom of the bracket. It would be better to have the fin on the inside of the bracket to help eliminate lift!

 

[Mike Hughes]

I have no issues with lift Don. The design is built specifically so I can adjust lift and anti lift depending on how the boat handles.

The bracket turnbuckle does 2 things Duke. It is there to adjust and true the fin to the center line of the boat. It also helps the bracket to stay in place. You have a big fulcrum there with a big fin 4" from transom and a little 1" foot print on bracket. Over time the bracket will crush into the back of sponsons and loosen up the bolts. At which point it starts to tear up the sponson transom more.

We have some rules in ERCU that don't allow hooked or bent fins in the water. It needs to have a straight leading edge. I always want to be able to adjust fin to help the ride.
Mikey, I don't know. I just matched to my fin on the 91 that works good. I would say it is about that.
Mike

 

[Mike Hughes]

As a side not, structual angle is not 90*. It is 89*. So there is no way unless You mill it that it will be true to the center line of the boat. That is also assuming the back of your sponson is 90* to the center of the boat. Both of which I would bet are not on most boats. We have been doing it this way for 20+ years. It came about when the Mutt 2 started into production. There have been a few nationals won by Eric and Mark with this setup.

 

[Duke Mordja]

Thanks Mike.

I see how this can help a TON. Looks like a good winter project for some of my boats.

 

[Mike Hughes]

Here is how I check. Clamp a piece 3' piece on angle to the turn fin. Now measure to some point on the boat. You will be surprise on how off it can be even when it looks good. Some boats don't have anything like a sponson edge/air trap to pull measurement from. Make a mark half between sponsons. Then make a mark half way on transom. Draw a line. Done. Measure from there.
Mike

 

[Jerry Dunlap]

The turn fin Mike created is on my 1985 BOAT with a rear wing. The BOAT is fast, but had a tendency to flat spin in a tight turn. And if you want to win in ERCU 1/10 Scale you need to be able to corner. After seeing how well Mike’s Winston cornered, I figured I needed to try a new turn fin.
JD

 

[user 21992]

Good job Mike, and great info. THANK YOU FOR SHARING !!

 

[LohringMiller]

When you get into the big stuff the setup gets really heavy duty. Below is the turn fin on a gas sport hydro.

Lohring Miller

 

[Timbo Whalen]

JD like how well my 1/10 91 winston was turning in the corners. He asked for one of my turn fins. Just finish it up today.

View attachment 297466View attachment 297467

Similar setup to what the big boys run..... the great Chip Hanauer explains it well in the video below-

 

[Mike Hughes]

The big hydros did not run big turn fins for the longest time. Hence the reason they called them skid fins. They spent more time sliding thru a corner. The first boat that really started using this fin setup and running a barn door for a fin was the 2001 Elam Plus. Saw that boat run at San Diego. It ran away from the fleet in the corners. We had been doing large fins for some time and I always wondered why they never went down that road until I saw the Elam Plus.
Mike

 

[Timbo Whalen]

The big hydros did not run big turn fins for the longest time. Hence the reason they called them skid fins. They spent more time sliding thru a corner. The first boat that really started using this fin setup and running a barn door for a fin was the 2001 Elam Plus. Saw that boat run at San Diego. It ran away from the fleet in the corners. We had been doing large fins for some time and I always wondered why they never went down that road until I saw the Elam Plus.
Mike

Hanauer explains all that, and makes the comparison.

 

[Mike Hughes]

Never watched the video. Just my personal experience. Been building turn fins for a long time now.
Mike