Running With No Muffler

[brit_hunsicker]

Just talked to my dad, who knows a good amount more than myself in both fields. He said no way would he do it. He said yeah it is likely to work okay for a while but over time he said it wouldn't hold up. Too hot and if the impeller failed, you'd start melting the PVC. Guess I should look for a fiberglass or stainless alternative.

[CanadaNautiqueGuy]

I'm installing a FAE and was wondering if I could get rid of the muffler. The FAE doesn't have a back flow flap. Is that an issue if I take out the muffler?

[a0128]

Thanks for the suggestions and photos! So I guess my real question is, does anybody know if PVC will withstand enough to be used as exhaust piping? If so, it's a done deal. I can whip that together in no time. I personally don't see any issues, but somebody out there may disagree.

You will need to use CPVC pipe. It has a max working temperature limit of 200 F.

[Nordicron]

I'm installing a FAE and was wondering if I could get rid of the muffler. The FAE doesn't have a back flow flap. Is that an issue if I take out the muffler?

I'd be worried about that! I know I'd never take my muffler out unless my FAE had a flap which it doesn't right now.

Does anyone think there is much benefit performance wise removing the muffler though?

[TRBenj]

Minimal to nonexistant performance increase on an otherwise stock boat. Big increase in sound volume. Reversion is not a concern ether way, even without mufflers or flappers.

PVC is a bad idea. Stainless tubing or all hose would be the most straightforward.

[Treybizttu]

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The reason I chose to replace my muffler wasn't due to volume or performance but based solely on the fact that the stock muffler was almost smashed flat and I didn't really want to pay what they wanted for a new one. It just so happened that a Y pipe popped up for sale before I found a used replacement muffler.

During my search someone posted this video and I was sold....


https://www.youtube.com/watch?feature=player_embedded&v=jpdTlUTukU4

[core-rider]

I'm installing a FAE and was wondering if I could get rid of the muffler. The FAE doesn't have a back flow flap. Is that an issue if I take out the muffler?

I'd be worried about that! I know I'd never take my muffler out unless my FAE had a flap which it doesn't right now.

Does anyone think there is much benefit performance wise removing the muffler though?

I don't understand why the FAE would need a flap. It is underwater all the time unlike a normal thru-hull exhaust and is pointing downward instead of straight out the transom. I don't really understand how water could move up into the FAE like it could into an open thru-hull without a flapper. The reason water flows into an open thru-hull is because it is above water when the boat is on plane. When slowing down water behind the boat will flow into the open thru-hull because it is now moving faster than the boat. With the FAE underwater all the time and pointed down I don't see the same potential for water flowing into the engine.

I've been wrong before though.

[xrichard]

I'd be concerned about water entering the FAE without a flapper. The opening is not pointed down--it is more of a 45 degree angle. Even if you're not concerned with water entering when you're coming off plane, you might be concerned about it when backing up....especially if you had to back up with some speed for whatever reason.

[TRBenj]

Water will not revert into the engine without a flapper, fae or no fae. The only way for this to happen is for water to come in with such force that it is able to rise higher than the exhaust risers on the engine. This is not going to happen. It would require a very large wave approaching from the rear whose peak is higher than the transom, and the boat would have to stay low (not rise up with the wave when it hit). You are going to have other problems if this happens- like a flooded or sunk boat. Backing up will not do it. This is an irrational fear.

None of my flap-less vintage cc's with log manifolds (no risers) have ever experienced reversion. I do back up from time to time. Lol.