Exhaust sound question

[Donziweasel]

I have no idea why I started thinking about this now, maybe becuase it is winter and I am bored. Anyway, my 16C with 350 CID came with the quik and quiet exhaust (totaly switchable) and also came with the standard Corsa exhaust tips with mufflers. I wanted it louder, so I pulled them and tried to take to baffles off. They were welded in and I didn't really like the look anyway. I ordered a set of Livorsi tips with internal flaps. Here is the link, scroll down to Exhaust Tip Muffler Options 4 inch. I got the angled ones with flap. I have no baffles at all in them.

http://www.livorsi.com/catalog/flaps.htm#EXHAUST_TIP_MUFFLER_OPTIONS_-_4”_ONLY

Since I put them on, they level of sound is great, but the tone sucks. Idleing it sounds great, but on a plane it sounds more like a "rat tat tat" than a deep, throaty V-8 sound. Kinda annoying acutally. I found myself running in quiet mode much more than I would have liked. Any suggestions to get that deep throaty tone above idle without losing any sound level? Am I describing well enough so that what I said makes sense?

[MOP]

Do a search on mufflers, there have been a few good posts.

Phil

[mphatc]

There's some information on the Corsa website in the automotive section on their muffler technology . .this may help to will explain part of the difference.

It is my understanding that the sound technology they use is incorpprated in all their mufflers . .

Mario

[RedDog]

Mario and Phil - I don't think you read his post entirely. He removed his mufflers by replacing the tips with non-muffled ones having an internal flapper only.

Now to your concern, I don't know. I did the same thing you did but I like my sound. But then I have a big block :wink:

I do get a tap-tap at idle speed as the flapper rattles in the tip. As RPMs go up the flapper doesn't rattle anymore since the exhaust flow holds it open

[Donziweasel]

Red Dog, you hit the nail on the head. I know a big block would sound better, but I have heard small blocks that have a nice growl as well. My flappers are rubber and are silent. It is the tone of the engine.

[Walt. H.]

D.W,

You're in front of the sound you're leaving behind when you're on plane, you would be pleasantly surprised how nice and throaty your engine sounds if you can hitch a ride in someone else's boat and trail behind yours, or just stay drifting in another boat and have someone do a fly-by with your 16-C.

Hope this helps, cause I use to think the same about my SBC.

Walt

[kjly63]

I also have that tap tap tap sound when at idle with the metal flappers. Mine are Stainless marine. Has anyone come up with something to quiet this? (maybe a rubber ring or something) I get asked all the time if something is loose on the motor and is rattling around when at idle:frown:

Ken

[Donziweasel]

Thanks Walt H for the advice, makes sense. I could also get the Livorsi inserts, they promise a more throaty sound but you lose 5-6 decibles. I guess I would rather have a boat that might be a little quiet but sounds good vs a loud boat that sounds bad.

[Carl C]

I also have that tap tap tap sound when at idle with the metal flappers. Mine are Stainless marine. Has anyone come up with something to quiet this? (maybe a rubber ring or something) I get asked all the time if something is loose on the motor and is rattling around when at idle:frown:
Ken Even my rubber edged flappers make a little noise at idle but I've still had nothing but compliments on the sound. I'd like to hear it from another boat but I don't like to let others drive my boat because these are not easy boats to drive at first.

[Walt. H.]

D.W,

I doubt very much you'll think your boat sounds bad once you hear it going by away from you, unless you mean "bad" in a good way.:yes:

Ken & D.W. Like Carl said even the rubber edged metal internal flappers rattle, mine do too and yes at an idle with the engine cover open it sounds like something is grinding.:smash:
But hey! How long do you run it at idle speed compared to the other 99% of the time when it's running above idle.:yes:

Carl,
I'm sure you'll find 5-Donzi pilots at a gathering you would trust to do at least a straight line pass for you with your 22C, Hi-speed donuts will be optional.:crossfing

[Carl C]

Carl,
I'm sure you'll find 5-Donzi pilots at a gathering you would trust to do at least a straight line pass for you with your 22C, Hi-speed donuts will be optional.:crossfing You got that right and I'll do it. I'll bring the camcorder.

[Donziweasel]

It's not the flaps. They are internal and pure rubber. It is the tone of the engine. It is high and sharp vs. low and throaty.

[Walt. H.]

D.W,

The Livorsi link you posted states that all their internal flappers are made from no burn S/S, what you are seeing is the rubber coating.
But i'm not talking about the sound of the flappers, i'm saying to listen to the sound of your boat from behind as others hear it, when you do that you might just change your mind.

Its the same reason your engine sounds quieter as you get up on plane then the louder sound you hear when you're going thru the no wake zone, at speed you're moving so fast away from the sound of your exh you can actually hear more of the engine air intake humming sound coming out from under the hood/hatch and the noise of the wind hitting you in the face from over your bow.

With that said: I'm real Horny for a Hi-speed boat ride now,:yes: but living here in NY. thats not going to happen until mid May. Bummer!:mad:

Well a little Flat Bottom circle drag boat racing will have to do for now.
http://www.schoutenranch.com/clips/longbeach06.wmv
The video will play even though it says action cancelled.

[MOP]

You can do a fair amount tuning the sound with baffles, like I posted earlier do search on mufflers then you can PM a few guys to get their opinions on how their boats sound and which way to go.

[kjly63]

No complaint on the sound. has got to be in the upper 90's db range. NICE:wink:

[Donziweasel]

I know it says stainless steel flap, but bought mine last year and they are rubber. I played with them and "rolled" the rubber.

Walt, I am with you, ready to get back out on the water.

[Barry Eller]

Click on the link at the bottom of my signature. When at idle in neutral, the RPMS are high enough to keep my rubber flappers from hitting the tips. When in the water in gear, RPMS are lower and the camshaft profile causes the flappers to slap a lot. I can hear them over the no muffler exhaust of the 502.
But metal flappers would be a lot louder.

[RickSE]

Weez, also remember that your high elevation significantly lowers the compression and bark of your motor. My drag car sounds like a real race car in Phoenix at 1200' :wink: , once I bring it back up the hill to 7000' it sounds like someone drilled a big hole in each piston :yes: . Just no compression and compression is what makes the sharp bark.

[Cuda]

Are the manifolds stock Merc? I know when I put EMI's on my SBC, it had a MUCH throatier sound than the Mercs at idle, or running.

[Donziweasel]

Yeah, they are stock, I just can't afford a new $1200.00 set right now. Rick, you are right, I never accounted for altitude. Could definetly make a difference. I will try and notice the difference when I run at Powell, even if I have the 18 I am still planning on bringing the 16 as well. Did your dad order the 16? If so, did he go with the V-8?

[BigGrizzly]

I have CMI tips with a what is called a wave baffel. no ratta tata at all ihave hears what you are complaning about and thoes type of tips make it. Look to CMI to see it I won't be able to explain it