Modifying early 911 muffler, Opinions needed Options

[dion9146]

Hey guys, thought I'd ask the 914 crowd for an opinion....I know, that can be dangerous.

Check out this thread I started over on the bird board. I'm looking for a nice, lower rumble using a stock early 2 in, 1 out muffler. I do not want to modify it like the early 2 out sport style, Yes, that's too loud for what I'm looking for. I'd like to stop setting off car alarms in my client's parking garage.....

So before I start cutting, I wanted to get your opinions on what and how much I should cut. (IMG:style_emoticons/default/sawzall-smiley.gif)

http://forums.pelicanparts.com/porsche-911...ons-wanted.html

Thanks,

Dion

[dion9146]

Good feedback Ron. But if you also look at the suggested mods to the solid divider cuts in the original article when installing the 2-out sport pipes into the lower chamber, it makes no sense at all. Why even modify the upper chamber when the exit is welded shut, and all of the exhaust pressure is entering AND exiting in the lower chamber?

That's why I got creative with the spraypaint brush. (IMG:style_emoticons/default/smile.gif)

[pcar916]

Good feedback Ron. But if you also look at the suggested mods to the solid divider cuts in the original article when installing the 2-out sport pipes into the lower chamber, it makes no sense at all. Why even modify the upper chamber when the exit is welded shut, and all of the exhaust pressure is entering AND exiting in the lower chamber?

I agree until after a little totally theoretical noodlin', I figure they cut on stuff until either the back-pressure readings were matched to the carbs or, less likely, they were trying to keep the same approximate volume in the canister so the timber was what they were shooting for.

The later sounds more like Ferrari than Porsche, but a smaller cavity will definitely sound different. The original muffler resonated out lots of the pulses and kept drone to a minimum. The 2-out sport muffler definitely has a 4000 RPM drone in a 2.7L motor. I don't know about the current 3.6L. I have SuperTrapps now anyway so my 2-in 1-out has been in the attic for the last 11 years.

Frankly, the sport muffler on a 2.x Liter Porsche motor is one of my favorite sounds in the whole world. No matter what I do I'll never achieve it with this 3.6. I can't even experiment anymore. An auxilliary oil cooler is in between the pipes now.

The way you have it drawn may be the bomb. Be sure to let us know! (IMG:style_emoticons/default/driving.gif)

[Brando]

ITBs and a dual-in dual-out DANSK muffler will give you that sound.

Of course, you're not just modifying your exhaust for the sound of it, right? You're doing this to get some performance gain? Most anything is an improvement over stock.

The later sounds more like Ferrari than Porsche, but a smaller cavity will definitely sound different. The original muffler resonated out lots of the pulses and kept drone to a minimum. The 2-out sport muffler definitely has a 4000 RPM drone in a 2.7L motor. I don't know about the current 3.6L. I have SuperTrapps now anyway so my 2-in 1-out has been in the attic for the last 11 years.