260 sonic porpising
 

hello,
new to forum,i have a sonic 260 prowler,just purchased in summer of 08,496 mag 22 bravo 1 4 blade. i have a problem with the boat porpising at all speeds but wot unless i use the trim tabs. any thoughts ideas would be greatly appricated,thanks

My old sonic did the same thing. Had to use the tabs or it would do it. I have been told there was no fix it was a design problem. I loved the boat just not real fast but rode great in rough water. Nice user name.

i guess your prowler was a 2003 did u do any performance mods i was thinking about a supercharger but was concerned about the porpising. yes nice name.

porpising
 

I do not own a sonic however have been in and owned many boats. One boat in particular had simular thing going on. My problem wound up being the drive height position. The drive was actually installed from the factory about a 1/2 inch higher than other makes. An experiment from the factory I'm pretty certain. What at least helped noticably was an intimidator 3 blade prop. It's similar to a clever type prop. At least see if you can try one before purchasing one as I would hate to see you waste the money if it didn't solve your problem.
http://www.hydromotive.com/int_3.html

Good luck and be sure and keep me posted.

John

i tried a mirage plus 23p 3 blade which helped but seemed to list the boat to the port side not sure why it would do that. i could run without tabs but could only trim drive very little before i would need to use the tabs,thanks for posting

porpising
 

Sounds like you might be on to something though. The mirage is what I noticed my problem with the most. If you are able to try an Intimidator get the 24 pitch. You'll lose a little speed at lower RPM's as your mirage however it will pull harder and probably a little more top end. They are not as efficient as a mirage.
John

i will start my search for that prop worth a try thanks

prop search
 

No problem. I hope this helps for you. Don't worry about it though just go have fun. I am not looking at your first post at the moment however does this still happen if you have your drive tucked in?
Regardless I'm certain you'll see some results with the right prop.

Take care and good luck.

John

I haven't tried it on a sonic, but sometimes a nose cone on the drive can settle down a loose boat. It turned a chine walking 25 checkmate convincer into a boat with perfect manners, and it was only a 55mph boat, which is well below the speeds nose cones are recommended for. Perhaps you can swap drives with someone for a day to try it. As you've discovered, different props can help too.

Call Brett at BBlades. He can help with the problem. You may need to try and add some lead ballast to the farthest forward compartment. I use 150# of lead in my Spectre to calm the porpoise. Maybe you could test by getting a buddy to ride up in the v-berth as far forward as possible. http://www.bblades.com/