Formula Silent thunder help
 

Hi, I got a 89 242 with that fun killing swim plate. Does anyone know if its an empty box with sound dampening shapes inside? Or are there pipes or exhaust hoses in there. I want to do surgery to it but kinda want to know what I'm getting into . Thanks

I think you just remove it and put on some rubber flappers on the back. Mine came with it already removed. if you google it, i think others have removed them.

I don't want to remove it in case I sell the boat. I want to rework the crap inside hiding the sound

it’s just a hollow box with water inside to silence the exhaust...if you were to remove it, it will expose pipes on the transom. Put some flaps on them and go boating.

This. Just a big empty box that holds water to dampen the exhaust. Buddy of mine opened it up, best thing he ever did.

If its just a hollow box. Couldn't I just cut out the baffle inside the tips and put flappers over those rectangular tips? Or redo them with round tips and flappers ? The platform is useful and suits the boat.

only the bottom of it comes off when you unbolt it.

actually on my old 311 we just took a hole saw and put some measured holes in it, gave it a great sound, was still usable and the water in it drained out more quickly..

if it's like my 272 there are some little baffle plates sitting in a few inches in from the tips. I just took a long sawzawll blade and cut them out. I think they are just glued in so you could probably even just knock them out as well. worked perfect for me, just gave me a little more noise but not full on flapper tips. other option is to just drill some holes in the bottom of the platform although I've heard people say if you get to wild with the size of them you can get some funny vibration noise at speed.

There is not going to be a significant increase in sound for YOU inside the cockpit with that platform still attached no matter what you do. Even when I had a newer 382 with the molded swim platform and straight exhaust under it, the sound wasn't that loud unless you were standing on the dock. The reason is the sound exits below the platform. Other boats that exit above the platform leave a much louder sound signature in the cockpit.