Very loud exhaust on SX drive

Finally made the switch from MerCruiser to VP for my bowrider. Have twin 280s on my cruiser and love them. New boat has a 4.3 with the SX drive. Problem is that I'm now by far the loudest boat on the lake, and everyone is complaining. Is there a way to bypass the rectangle exhaust ports on the lower end of the drive (see photo) to divert the exhaust and sound through the prop like a Merc?

Once the boat is on plane, it is essentially open exhaust as the ports are above the cavitation plate. Note, the bellows are in great shape - clamps are tight, engine is sound, no issues anywhere other than the loud exhaust. Thinking of selling the boat already if I can't address this... There are a handful of articles out there about this, but no real cure. At idle in the water it sounds identical to my Merc 4.3.

Thanks VERY much in advance.

Chris

VP 200 series drives ( I know, you have an SX) have undersized exhaust ports for V8s and as such, I changed over my 280 drive thru cav plate exhaust system to thru the transom with mufflers...ended up using fiber glass Centek "mini's" that were plumbed as follows...
4" exhaust port (engine's exhaust elbow) to a 4"to 3" right angle adapter... muffler(s) to a 3 " right angle out the transom at the corners.... 3" bronze exhaust ports..... flaps on exterior are essential. Quieter at speed and also much less back pressure... got another 400 RPM out of engine.

Re: " Once the boat is on plane, it is essentially open exhaust as the ports are above the cavitation plate"..... on 280 and later 200 drives this is also a design "feature"....

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Christo 604 said:

Finally made the switch from MerCruiser to VP for my bowrider.
Good for you! You will not regret it!

Have twin 280s on my cruiser and love them. New boat has a 4.3 with the SX drive. Problem is that I'm now by far the loudest boat on the lake, and everyone is complaining. Is there a way to bypass the rectangle exhaust ports on the lower end of the drive (see photo) to divert the exhaust and sound through the prop like a Merc?
You would lose some performance if you were able to.

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Once the boat is on plane, it is essentially open exhaust as the ports are above the cavitation plate. Note, the bellows are in great shape - clamps are tight, engine is sound, no issues anywhere other than the loud exhaust. Thinking of selling the boat already if I can't address this... There are a handful of articles out there about this, but no real cure. At idle in the water it sounds identical to my Merc 4.3.
The "thru transom" exhaust w/ mufflers may be your best bet.

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