Ridiculously loud exhaust

doublestuff · doublestuff's Garage

There was a recent post with someone asking about putting a glasspack muffler where the cat goes on an SC, then exiting out the stock location.

Well, I tried that for about a week, but after the sound waves knocked over a few motorcycles and several cows dropped dead in fields as I drove past, I took it off again. Here is a clip in case anyone wants to try it. It sounds AWESOME, but to get the full effect you need to turn your speakers all the way up. Then press them against your ears as hard as you can.

http://www.youtube.com/watch?v=FDB7EbQeqAA

Jason

Talewinds · Talewinds's Garage

I tried that a few weeks ago with just a premuffler in place of the cat and no muffler. It sounded TERRIBLE. Loud, yes, I can deal with loud. But the audible quality was way beneath the character of the car. It just sounded like a 90' Buick Century with a broken manifold.
Besides, the engines in their more or less stock configuration require at least a little back pressure to perform well.
Heck, I'd have left it the way it was if the car had sounded even a little like one of those old mufflerless vintage race cars like a Carrera 6 or something, but it just sounded like *****.
Nice try though, now you learned what the answer to aftermarket exhaust ISN'T like I did.

jimbauman · 06-14-2009, 01:50 PM

BUT, did you notice an increase in HP??

doublestuff · doublestuff's Garage

Quote:

BUT, did you notice an increase in HP??

I don't think it made as much horsepower as my k&n sticker

Roc Doc · 06-14-2009, 02:24 PM

The thing is, that a flat 6 wants individual exhaust from each bank, unlike a v8 than can benefit from a X-pipe. So if you're running headers, the best thing would be mufflers attached right to the collector. I've heard the Hushpower mufflers with an LS motor and they sound great, and I think they might make a good choice for a 911...if they'd fit.

Ray 911s · 06-14-2009, 02:38 PM

I still need to finish this up and then apply some high-temp paint, but anxious to hear what it sounds like. Equal length pipe with scavenge/cross over in the middle. No mufflers, but hopefully long enough to produce a little pressure.

EarlySport · 06-14-2009, 03:41 PM

Many years ago I put a flowmaster muffler ( 2 chamber 3" in and out ) in place of the cat on a 3.0SC. I deleted the rear muffler, and just ran a tailpipe from the flowmaster straight out in the factory position. It was ridiculously loud. I cut the muffler apart and inserted a number of mesh sheet panels and steel wool packing - this made a huge difference and it actually sounded pretty good.

While I can't say it made a measurable difference to power, it saved about 30lbs of weight from the very rear of the car..

I have built a similar system on my current IROC project - using a stainless twin pass muffler. This may actually be too quiet for me ( like OEM loudness levels ), so I might substitute the twin pass muffler for a single pass. In this case I have a tailpipe that bends it way to a twin centre outlet tailpipe. Again - a big weight saving from the OEM system.

Dantilla · 06-14-2009, 04:04 PM

At yesterday's autocross, I was told once again that I my '73 was the best sounding car there- This time by a GT-3 owner.

Just SSIs and a Triad West 2-in,2-out muffler on a stock 3.2.

JohnJL · 06-14-2009, 04:43 PM

Yep, SSIs or even bursch's into a flowmaster 2-in-2-out sound good to me and I get compliments on it all the time. Too loud for the Targa tho.

signature65 · 06-14-2009, 09:36 PM

I love the raspy 911 sound.....sends shivers dowm my spine. I have a stock muffler with the guts cut up and twin tips added......sounds awesome...loud yes....

Porsche-O-Phile · Porsche-O-Phile's Garage

Quote:

Originally Posted by Ray 911s

I still need to finish this up and then apply some high-temp paint, but anxious to hear what it sounds like. Equal length pipe with scavenge/cross over in the middle. No mufflers, but hopefully long enough to produce a little pressure.

Is that a Manta?

criv911 · 06-15-2009, 05:21 AM

I have a Fabspeed muffler bypass, and I love the sound. I don't think it's too loud. I get compliments on the sound all the time. I wouldn't want to drive across country in it, but I can listen to music just fine. Maybe I'm old and the hearing is going. Does anyone know if the cat quiets the sound more than a muffler in that position? When I did this I was going to replace the cat with a magnaflow. I bought the muffler, and it's still in the box. I was afraid that I would go through all the work and not like it as much.

Mattcamp · 06-15-2009, 07:26 AM

Quote:

Originally Posted by criv911

I have a Fabspeed muffler bypass, and I love the sound. I don't think it's too loud. I get compliments on the sound all the time. I wouldn't want to drive across country in it, but I can listen to music just fine. Maybe I'm old and the hearing is going. Does anyone know if the cat quiets the sound more than a muffler in that position? When I did this I was going to replace the cat with a magnaflow. I bought the muffler, and it's still in the box. I was afraid that I would go through all the work and not like it as much.

My friend....your hearing is not going but it's already gone.

I ran a muffler bypass for about 1 day.......holy @$%^!!!!

It sounded like a drag boat. Way too loud to enjoy, and I like loud.

Ray 911s · 06-15-2009, 03:54 PM

Porsche-O-Phile, it's not a Manta. I'm not sure what brand it is. Not worth anything, so a good subject for experimentation.

criv911 · 06-15-2009, 04:36 PM

I don't mean to argue,but I really don't think it's that loud. Harley's are way louder, so are ricers. Does the cat do more to quiet the sound than a muffler? I really don't like a really loud car!

jasonlee · 06-15-2009, 05:11 PM

I had my car in the shop a couple of weeks ago, the owner calls me and says, we love the way your car sounds, mean and loud. I am running a Bursch cat bypass, and a Flowmaster 1 in 2 out, 3.0 SC. Loud enough to set off car alarms, but the Harleys in my city are louder. Wife doesn't care for it much, but my 5 your old son and my daughter love it.

Boomtown Rat · Boomtown Rat's Garage

I love how your camera shakes and shudders (first scene, in your garage?), when you rev a bit.

I've got a custom (one-off), 1 in 1 out, that has little to no filler in the secondary muffler, plus a cat-bypass on my 3.2 Targa. I just changed from the stock secondary muffler and cat to this "solution" a few weeks ago. Increase in HP is noticeable! Breathing freely from 4200 all the way to 6300 rpm. Problem is I got pulled over and cited in Lugano a week after installling it. Not quite as aggressive as yours, but too aggressive for the authorities here...

ruby911 · ruby911's Garage

I recently posted about putting a muffler in the hole where a recently removed cat was and eliminating the Porsche muffler behind the bumper - but my question was about a Carrera.

Regardless, what you guys are showing here is exactly what I was asking about.

Doublestuff - I could not imagine what it sounds like in person, but in your video it sounds pretty damn good!

earlysport - do you have any sound clips of yours?