Through hull exhaust

[jjt98]

What are the advantages and disadvantages of through hull exhaust?

Are they a lot louder? Do they give you more power and better gas mileage?

 

[180shabah]

Re: Through hull exhaust

There is no power advantage untill you get up around 400hp.
Are the louder? Absolutely.
If not installed propperly, you risk water intrusion - bye bye engine.

The only advantage for most, is it sounds cool - for about the first 20 minutes.

 

[Snobike Mike]

Re: Through hull exhaust

Advantage - They are Louder
Disadvantage - They are louder.

 

[Utahboatnut]

Re: Through hull exhaust

Advantage is you have a loud boat(I think thats an advantage?)
Disadvantages are they are expensive, more possibility of water back thru engine(BAD) no power gain until a 383 stroker and above no mileage gain at all, two more holes in the transom.

 

[Philster]

Re: Through hull exhaust

The advantage: If you have a twin-engined, 35-foot Fountain powerboat with Twin 500HP EFI Mercury Racing engines running through Bravo XR drives, you get to have an exhaust that can accommodate massive amounts of exhaust gases and water rushing out of engines pumping out over 500 HP each while you run offshore at 75 MPH.

The disadvantage: If you have a regular ol' boat or basic performance boat, the sound gets annoying in-shore, and there isn't much performance boost if you are running manifolds (maybe zero HP).

If you invest 4 grand in headers, you get a few more HP.

 

[jjt98]

Re: Through hull exhaust

How hard is it to convert a through hull exhaust to a normal below the water exhaust?

I'm looking at used 20' ski boats and several that I'm interested in have through hull exhausts. I would prefer not to have this type since it sounds like the only difference is the boat is louder. I don't want to be labeled as the noisy guy on the lake!!

Would this conversion be worth it or should I just look for boats with normal exhausts?

 

[Kev144]

Re: Through hull exhaust

Leave them. I guess if I were an old grouch or what have you, i wouldnt like em. I run a outerlimits boat from work with tripple 1075 mercs running at over 150 mph. It sounds awesome on these motors or even on a 350 chev. Some still have silents choice where you can switch it from thru-hull to quiet.

 

[180shabah]

Re: Through hull exhaust

If the boat already has it, are the tips below the waterline? If so, the difference in sound is minimal.

FWIW - it would be cheaper to add mufflers, than to move the outlets.

 

[ringmaster72]

Re: Through hull exhaust

Thru hall is great. Nothing sounds better than a hi perf. motor humming at 4500-5000 rpms across the water.

 

[H20Rat]

Re: Through hull exhaust

Thru hall is great. Nothing sounds better than a hi perf. motor humming at 4500-5000 rpms across the water.

depends if you are the boat owner or the rest of the lake that has to hear it.

 

[haulnazz15]

Re: Through hull exhaust

depends if you are the boat owner or the rest of the lake that has to hear it.

Or the operator/passenger trying to have a conversation.

 

[smokeonthewater]

Re: Through hull exhaust

Thru hull can be obnoxious Nothing is more irritating than any motor with no muffler humming at 4500-5000 rpms across the water.

Fixed it

I actually went as far as buying a set of 4 pneumatic cutouts before deciding I want my exhaust QUIET..... the ONLY time loud is cool after the fiirst day showing off is idling away from the dock..... Imagine how stupid you'll feel thundering down the river with your hair blowing anouncing to the world how bad you are and then a little bass boat jumps your wake and quietly flys by you like you're standing still..... Then another quiet boat shows you what's up and another and another...... Everyone and their brother will be racing you whether you want to or not.
To do it right costs big $$$$ for mufflers and still opens holes for possible water intrusion

 

[Utahboatnut]

Re: Through hull exhaust

If the boat is an inboard ski boat that has them already I would leave them alone, see how it is then decide if you want to add mufflers or not. Usually the ones that come standard that way are not nearly as loud as adding them on later.

 

[jjt98]

Re: Through hull exhaust

Thanks everybody. How much do mufflers run in case I need to go that route? It will either be a 5.0 or 5.7. Are they hard to install? Will mufflers decrease my power?