Muffler Wowes... Too Damn Loud
 

My 79 911SC has SS SSI's and a dual in dual out muffler that is entirely too loud, not only according to my wife but I have been driving the car for 2+ years now and have a serious headache and possible hearing loss...

Any suggestions for an ez swapout? Somethin a little less obnoxious without suffering in the performance area??

Thanks

Alex in NJ

1979 911 SC "worked"
1969 Lincoln Mark III (For Sale)
2001 Chrysler Minivan (Family Mover):p

What muffler do you have on the car?

I had the same problem. Put a Dansk sport 2 in 1out on last week. Now it has a nice pleasing tone that is not too loud. Anyone want to buy a 2 in 2 out triad??

Jeff

First try plugging one of the outlets and see how much that quiets things up. Could be a cheap fix for you. Give you chance to see if you really notice a performance drop going to a single out muffler.

I think there must be somethin' wrong with that fella!! ;)

:D

Jeff,

I feel bad that I have your original Dansk! But not so bad that I'd be willing to give it back...........

Call me when you have minute.

Cheers,
Jorian SmileWavy

Ya, there is, he CAN'T HEAR :)

Jeez, I didn't think I would get such answers...

Should I just drive with earplugs?

Mossy hard to give you better options until you tell us what you have that is too loud.

But no, ear plugs and muffs are not the best options.

How about those noise restrictor in the tail pipe? There was a recent thread on this.

John

Go back to stock exhaust and give me your "loud" exhaust! j/k

Mine is super stock quiet right now. Actually, that should change soon. Everyone has different taste, right?!

Should be able to put a stock 74 2into1 muffler on the SSI set up cheap.

I have a 2in/2out on an 85 carrera. I think it sounds just right, but the wife and neighbors disagree--ok it does set off car alarms when I start it up. I had a muffler shop make a cap for one outlet. It really makes a big difference- even the wife doesn't complain anymore. Less than 5 hp loss on the dyno- confirmed on 2 different runs months apart. You will get questions about what the cap is for- I usually tell people it is an aerodynamic aid that keeps the rear end of the car down at speed- I had one old guy tell his wife that he already knew that!
Again, cap off one outlet and see if that helps.
Gary

3.0 with SSI, 2in2out 70mm.

A month ago I was asking the same questions, I called the vendor and wanted to know what they could do, they even offered to (for a small fee) re-baffle the thing for me.

I have since bumped the timing and mixture to get better HP and man it really woke that motor up! Was <5BTDC now is ~12BTDC and on the plus side some of the really deep exhaust drone is gone as well. There is still plenty of sound and I like it, it suites the car.

I don't use the horn, I rev the motor instead! ;)

I just sold my other single 2in1out with 84mm tip, but only because it wouldn't fit proper, I am waiting for payment to ship. When I first switched over I liked it because it was quieter, but now I am happy. Some guys are not complaining about the dual out but I am sure it makes a diff if you have a 2in vs 1in.

Cliff

I had noise issues on a dual outlet.....I plugged on side...worked great. On the REALLYANAL tracks I used a reducer on BOTH tips and was able to get the DbA level to 88 down from 96.

If that is the case, could you partially restrict both exits as to have the same area of the one with the other capped? Maybe a tiny bit bigger and still have the same effect on the sound. In this way, perhaps the lost 5 HP could be restored. Maybe, if you found a sweet spot, on a long shot, you might get more HP than the original.

I would tend to use a washer with a big hole and a tab welded on it at right angles and shove it in there a ways. Catch the predrilled tab from the outside with a rivet. Multiples of these could be installed, if needed and keep from restricting the total area of the exit.

A little kitchen table theory: the further away from the heads, and depending on overall header and muffler design, the less the pulsing has to do with performance. So much exhaust turbulence is created in the muffler that you get nearly a constant flow of gases at the tail pipe at higher RPM. When this is the case, restriction can be avoided using the turbulence for the quieting effect.

The latest exhaust designs I've observed have a 3 (on each side) into 2 and into 1 configuration. The "1" being a straight pipe of designed length. Older designs were just the 3:1 megaphone or variants. The newer design is essentially what Gary has now.

But, for the sake of the argument, I'm going to consider the stock style muffler as the "1." It worked for a lot of cars from the early's to '73 (or '74?) So, my conclusion is that it's all in the final area of exit as much as it is how it gets there. And if you can make if quiet in the bargain, well, purrrfect.

EDIT: Well, there you go. While I was typing, Mike said it. He's good at that. Short and sweet. (No, not him, his words,LOL)

I didn't try any other tuning, as I open the 2nd outlet back up when I want to play, or go to the track. The tuning possiblities sounds like a good idea though. Darn you guys, I thought I was at least done with my exhaust, now I have things to think about again:)
Gary