Engine noise reduction

[Lukeskywalker]

I have a 2018 23lsv. I was wondering if anyone has ever but any type of sound insulation to reduce the noise of engine? Any tips? Thanks

[Ronnie]

@Slurpee

[dalt1]

At what Speeds and conditions do you feel it is too loud? I have the same boat and just had a friend aboard that has the Supra SA450 with same engine, He commented how mine was so much more quite than his due to the surf pipe. We made a 15 mile one way cruise to restaurant with easily conversating all the way there at 24 mph and 3500 RPM. He said you couldn't hear at those speeds in his Supra. Always wondered why everyone said the new M engines were so much better? Have not been in an M/5 equipped boat but have no issues with mine. Now when foiling behind it at 24 mph and making a turn and the surf pipe comes out of the water it does sound like a Nascar for that brief moment but only behind the boat don't notice it inside. 

[Leftlane]

Agreed - also have an 18 and don’t think it’s crazy loud.  I also have the surf pipe and it clearly helps.  

[Slurpee]

So the 2017 and newer 23LSVs using the Raptor engine were produced with a nod towards sound insulation. 2016 was a noisy year.   When Ronnie and I measured his boat in 2017 against me 2016 it was almost as good OEM as mine with the MLV.

Fancy marketing aside noise is attenuated with decoupled mass. Like foam sandwiching heaving boards or mass loaded vinyl. 

I wrapped my entire 2016 engine bay in 3/4 of an inch of mass loaded vinyl and foam. Extensive sound measurements. It helps for sure. And most boats that folks comment on as quiet do Indeed have mass added for insulation. 

There are two other very important considerations as well. 

1) Engine RPM. If you fall for the myth of a low pitch prop is necessary or are forced into one due to altitude, then your engine is going to turn more RPMs. That’s more mechanical pieces moving faster and they will be louder doing that.  Regardless of what actual energy output is demanded from the motor. The best thing you can do for your boat is test several props and learn how to weight your boat. You should be in the 3000’s for about everything more or less. 

2) Get a surf pipe. Added it to my ‘01 and OMG. Beat the Silent Tip Turn Down Exhaust by magnitudes. The STE were better than nothing though. 
 

 

Edited July 3, 2022 by Slurpee