ew928

Having experienced the rumble of my ex-Audi and it's rust-lightened Ansa muffler, I figured it wouldn't hurt to experiment with the
whisper quiet S4 stock factory muffler.
Had been in an RMB equipped S4 and found that a bit too vocal for my daily driver so I wanted to see what the factory boat anchor will do.




Sound files here:
http://homepage.mac.com/ew928/FileSharing89.html

How do you upload sound files directly? Guess I'm rennlist challenged.
The throttle blips were recorded around 2 feet from tailpipe.
Idle was recorded close to the single rear outlet.
Didn't have a nice microphone so I used the built-in mic of a Ipaq PDA. Not the best sound quality but hopefully the general aural experience comes through.
Can now actually hear the exhaust somewhat in the S4 cabin.

The holes are about 1/4" in size. Cluster of 2 per side now. Going to try making it cluster of 3 holes in triagular array.
Not sure if the factory muffler is a dual chamber exhaust. Might need to keep the holes symmetrical side to side.

Keeper of the 928 shrine was worried this might sound too raspy.
Hope it's not too ricer.

Nomex on. Hope I don't get shot out of the sky like the Red Baron for this. Guess I can always slip a Razo exhuast tip over the factory exhaust.

Did this just as a noise-maker. Probably lost HP with this mod.

Ernest (NYC)

AO

Still too quite for my tastes. But A for effort!

I'll help you mod it at SITM... Only one tool required: BEER!

Bill Ball

I'm surprised a couple of tiny holes don't just hiss or whistle.

Jim bailey - 928 International

Ernest when you mentioned this to me before your post I was thinking holesaw type holes these look more like condensation drain holes !

Mongo

That's because he's hiding the picture of him sawing the muffler off

ew928

I'm still working on it.
Wanted to be stealth just in case it doesn't pass the NYC inspection.
Figured a couple of sheet metal screws or muffler tape if I wanted to return to stock.

Jim B. Figured if I got hassled about noise by explaining they're drain holes for the muffler. It came that way, Ossifer. Really.
Now the S4 muffler will NEVER rust away.

With these I just put in 1 bit and keep drilling away.
http://www.harborfreight.com/cpi/cta...emnumber=91616

Gotta love Harbor Freight.

So Andrew O., you gonna swiss cheese the stock muffler?
Just curious what that and the cross-over pipe will sound together.

Ernest (NYC) I just turn up the computer speakers to make it sound louder.

urnotthesameina928

Hi Ernest here is an idea to think of..Supertrapp. You can then make it as quiet or as loud as you like. Lots of baffles to choose from. easy to adjust..or what I would think would look best an internal baffle in an RMB.. Dave

Jerome Craig

Just a thought... a hole in your muffler may be a good way to gas yourself as the exhaust is exiting directly under the car. Like I said... just a thought, winter is over and I have no idea how much traffic you sit in.

ew928

Hole in exhaust is about 4 inches forward of the main exhaust outlet.
The holes are below the rear bumper valance.

I guess if I sit in traffic with a light tailwind I would be in trouble.

Wonder what happens to those side-pipe exhaust guys?

Ernest (NYC)

Nicole

Hey Ernest: Porken would be proud of you!

How much weight did you save with this mod?

ew928

I was wondering why the back end was feeling a little light in crosswinds lately.
Wait till I start on cross-drilling the gas tank.

How much weight can I take out of the battery by cross-drilling the lead plates?
More surface area with holes in the plates . . .

Ernest (NYC)

Mongo

Why not cross-drill the battery?? That thing is so heavy

Weissach

How much louder is it in normal driving?? Do you like it? I might do it before i install an RMB

ew928

Can barely hear the low growl in the cabin. The S4 is well insulated.
That's with 4 holes.
If you've got a little time, get a set of the stepped drill bits and go at it.
Not sure if using just 1 larger hole/side will affect sound.
See what just 2 1/4" hole sound like and go from there.
RMB is only a phone call away if the sound displeases.

I was just worried that it might turn the muffler into one of those Fart cans and their
blat blat blat noise.

Ernest (NYC) Really nice low rumble on drop throttle.

Jerome Craig

Not a criticism mind you, almost lost a friend to C0 poisoning a couple of years back. Side exhaust are outside the body of the car.

Jerome