Louder exhaust?

[gr8shot]

Sierra 18-2760

Curious if anyone has any experience with this exhaust bellows replacement? I'd like a little more noise out of my exhaust, but not ready to bite the bullet on $1000+ side exit systems or anything over the top like that. I saw a couple comments in a facebook group saying it's about the same as stock when going slow, but when you get on plane it's a bit louder since there's no exhaust running down through the prop anymore. Just curious on everyone's thoughts and if anyone has used this, or has any first hand experience? Thanks!

Will be going on my 99 sea ray that I just finished building a new 350 for.

 

[AShipShow]

What you've read is true in that its really only noticeably louder when you're on plane... However thats because theres a leakage path between the tube and the leg vs a bellows where its sealed off... Its only louder on plane because its out of the water at that point... At idle, everything is still under water.

 

[kenny nunez]

Exhaust noise.
My Donzi had 4” open exhaust through the transom and really loud. The guy I bought it from said the boat went 70.
I had to rebuild the transom and replace the gimbal housing so I also went back with the exhaust going through the drive using the short bellows. The boat still goes 70 on gps @ 5k. At normal cruise now it is possible to have a conversation.
And one other thing I noticed is the engine feels smoother since the exhaust pulses are balanced.

 

[Scott Danforth]

I would go with the tube you have shown. that will give you a bit more noise, however keep mama happy she isn't getting a headache from a V8 droning on while at cruise.

remember, if the Admiral aint happy...... no ones happy.

 

[62cruiserinc]

I have a 1981 Sea Ray 26' Sundancer with a replacement crate 350 engine.

The previous owner installed the device that you are asking about, which is called an exhaust tube (vs exhaust bellows which is the factory part).

I can't compare to the bellows because I never had one on the boat, but the sound is pretty good without being annoyingly loud. I have heard other boats similar to mine with bellows and they seem a little quieter (not on plane, at slower speeds).

For me, it's a good balance between some extra sound and not annoying people on the boat who don't care about engine sound.

It's certainly a lot easier to install than an exhaust bellows at replacement time.

Steve

 

[gr8shot]

As much as I'd love for it to pretty much scream all the time, we'd still like to be able to talk in the boat. But my wife is ok with a little more noise. She's been with me long enough that she has come to enjoy a little exhaust noise. Pretty much every vehicle I've owned, including her yukon, gets exhaust done. So only makes sense that the boat have a little more noise. I hear a few other boats go by and it sounds so good with a v8 cruising at 3k+rpm. And I can't hardly even hear mine and I'm in it!

 

[Scott Danforth]

I have been in sausage boats with twin 450hp 383 strokers and un-corked exhaust at 5500 RPM up to and MTI with twin Sterlings at 1200hp each running un-corked

when you need ear muffs to go for a ride, its a bit too loud.

I can tell you that the exhaust in my current boat cost more than building the motor did.....

so far, running on the trailer isnt too loud

 

[QBhoy]

All good fun for most of the time. I love it on my V8...but also love the fact I can turn it off too then most of the exhaust exits under water instead of the side exits. Useful for coming back to the marina late at night. Not everyone appreciates the sound really.
Ive never seen what you are thinking but will it make a mess of the transom with suit ? I know I get a fair bit of black out mine over the season and the occasional scorch mark to be cleaned too.
with my exhausts open I literally can’t talk to or hear what the guy in the boat next to me is saying and you can even feel the pulses in your chest standing next to it !

 

[achris]

.... I saw a couple comments in a facebook group saying it's about the same as stock when going slow, but when you get on plane it's a bit louder since there's no exhaust running down through the prop anymore....

It's actually the exact opposite of that.

The tube was introduced to allow the big block V8s to run with less back pressure on the exhaust system at idle. The exhaust was able to relieve out of the tube without being forced to push against the water column in the drive. Once the boat was up and planing, there was far less pressure from a water column (boat higher up, drive drawing less water depth), and the diffuser ring on the trailing edge of the propeller hub actually reduces the pressure even more, acting like an extractor system, pulling exhaust gasses out into a low pressure area.

As for being a 'bit louder'... Nah, I'd like mine even quieter, the quieter the better. If I want noise, I go to the drags. I go boating to get away from noise.

Chris........

 

[gr8shot]

As for being a 'bit louder'... Nah, I'd like mine even quieter, the quieter the better. If I want noise, I go to the drags. I go boating to get away from noise.

Chris........

Haha to each their own! I'm not young anymore, but not old yet either. For now I still enjoy the right amount of exhaust. I think wide open would be too much. But something more than the factory setup would definitely be nice for me.

 

[nola mike]

It's actually the exact opposite of that.

The tube was introduced to allow the big block V8s to run with less back pressure on the exhaust system at idle. The exhaust was able to relieve out of the tube without being forced to push against the water column in the drive. Once the boat was up and planing, there was far less pressure from a water column (boat higher up, drive drawing less water depth), and the diffuser ring on the trailing edge of the propeller hub actually reduces the pressure even more, acting like an extractor system, pulling exhaust gasses out into a low pressure area.


Chris........

But when you're trimmed up, there's not as much seal at the tube, so I'd think more exhaust gas would be exiting directly? Either way, I replaced the bellows with a tube on my 3.7. Not much of a difference IMHO. Thing sounds like a tractor at idle anyways...

 

[achris]

Trimmed up, not trimmed up, there's never much of a 'seal' on those tubes anyway.

Once running, with the much lower pressure in the drive exhaust cavity (caused by the low pressure area behind the prop) the exhaust will go that way, as opposed to trying to force its way though the water swirling around the top end of the drive. (ever looked down there when under way? There's a LOT of water being forced up into the gimbal housing.)

Chris....

 

[nola mike]

Trimmed up, not trimmed up, there's never much of a 'seal' on those tubes anyway.

Once running, with the much lower pressure in the drive exhaust cavity (caused by the low pressure area behind the prop) the exhaust will go that way, as opposed to trying to force its way though the water swirling around the top end of the drive. (ever looked down there when under way? There's a LOT of water being forced up into the gimbal housing.)

Chris....

No, I figured that section was out of the water on plane...

 

[gr8shot]

I've got to pull the drive and do a gimbal bearing anyway, I think I might order this and put it on while its easy to get to. I'm not that concerned about performance. Just want a bit more exhaust sound. The boat runs great as is, and makes enough power to bump on the rev limiter. And I don't really want to buy a new prop at this point in time.

 

[AShipShow]

Just wait until you have to do a bellows job... You're going to have to remove the bell housing to do the exhaust tube, at that point, might as well do your bellows and even shift cable.

 

[gr8shot]

Just wait until you have to do a bellows job... You're going to have to remove the bell housing to do the exhaust tube, at that point, might as well do your bellows and even shift cable.

The few people I've talked to that have installed them says they only take like 10 minutes to install, that its super easy. Maybe I'll have to get a little more information before I pull the trigger.

 

[achris]

The few people I've talked to that have installed them says they only take like 10 minutes to install, that its super easy. Maybe I'll have to get a little more information before I pull the trigger.

Don't need to remove the bell housing to install an exhaust bellows. Yes, 10 minute job to install the tube. About 20 minutes for the bellows, as you need to pull the bellows on with the special tool (instructions for building in the stickies, costs about $3) you need to pull and refit the drive....

Chris.........