Whiplash Sport 21 turn fin

[Raydee]

Guys I am having a issue with my Whiplash, the boat is pulling to the right. I believe that the turn fin is the culprit. THe fin is parallel to the sponson, the bracket is 90* and the bottom of the fin is straight with bottom of the hull. I am using a Blazer fin that is CNC hooked. If I pull the fin toward the front of the hull the hull drives perfectly straight BUT because of the angle of the fin it seems to be causing extra drag and slows considerably in the corners. I have tried to bend the turn fin bracket some but it really didn't make a big difference. I am wondering if going to a bent fin instead of the hooked fin might be a better idea for my setup? I am going to run the boat today with no fin and see if it goes perfectly straight.

 

[Raydee]

Well I put on a new fin with only a small bend in it and the boat ran perfectly straight today. The Blazer fin def held the sponson down better but the constant pulling to the right was killing me. I would much rather switch back to the Blazer fin if I can figure out why it is causing the boat to pull so hard to the right.

 

[tampa1330]

Well I put on a new fin with only a small bend in it and the boat ran perfectly straight today. The Blazer fin def held the sponson down better but the constant pulling to the right was killing me. I would much rather switch back to the Blazer fin if I can figure out why it is causing the boat to pull so hard to the right.

I had that same problem with my SS45. It was a hooked fin. It pulled hard to the right. It cost me about 5 mph. On my set up the fin had a negative angle and it was servely pulling the right sponson down causing it to pull hard to the right. Whenever I hit a wake the left sponson would jump and the right would just stay pinned to the water. My setup was a little more complicated to fix since it had been repaired at the back of the right sponson. I had to do glass work to get it right. but I just made sure that the fin was straight and the hook was paralell to the bottom of the boat. If there's any pitch upwards then it lifts and litch downwards it drags. Hope this helps.

 

[Raydee]

Yeah I tried pulling the fin forward and back and forward helped a lot but caused extra drag. I am going to take a better look at the hook in the fin and make sure it is perfectly parallel to the hull.