Also want to add, right now I am running a used Buschur TBE with Magnaflow muffler and high flow cat. The double magnaflow setup is quieter than running a HFC by a pretty good margin.

I got another exhaust idea!




I really want to do Option C but I dont have a welding machine.

I've actually narrowed down what annoys me about exhaust sounds. Its the deep bass sound. So my goal is not to just quiet the exhaust but to remove the bass or turn the sound to a higher pitch/tone.

What do you guys think?

Other than the actual split section, dual 2.25 should flow same if not more than single 3" ? I'm not just hoping the actual split doesnt hurt flow too much.

 

Why not try an offset magnaflow ? It should reduce the noise quite a bit more than a straight through design....

 

If your getting at the RRE stealth using an offset muffler, well I had that exhaust and it was not quiet.

I'm becomming a little skeptical for oval style mufflers, offset or center. With 3" piping there is limitted space left for the vertical cover for sound suppressing material. Although the horizontal ends might contain more material the vertical upper and lower portions lack. But round mufflers keep a constant width all around.

I've been looking into the the Audi S4 B5 exhausts. I really like how the crossover mufflers sound. Although we have different motors with our I4 vs their V6, I would like to try an almost true dual setup with one split center muffler and a rear cross over muffler.

The way I see it is that if I cut the exhaust from a 3" to a 2.25-2.5" then the smaller diameter would change the tone as well as make it quieter. I know the split section might hurt flow, but as long as its slightly (a couple hp) I dont mind. I'm gonna look around for the best splitter/reducer.

Remember the first page showes how to make a quiet 3" catless exhaust. Now I want to change the tone/sound!

 

dont forget that option c will be significantly heavier due to the additional piping. according to my calculations, the volume of an arbitrary length (L) of piping at 3.00" OD and .065" wall thickness will be .599 * L cu in. Multiply this value by the density of the material to get the actual weight. On the contrary, the volume of an arbitrary length (L) of piping at 2.50" OD and .065" wall thickness will be .497 * L cu in. Since you have dual pipes, the volume will be .994 * L cu in. The weight will then have increased by 1.66X from a single 3" setup to a dual 2.50" setup. For example, a single 3" pipe that weighs 20 lbs would be equivalent to running dual 2.50" that weight 33 lbs. I dont mean to rain on your parade but are you willing to increase the weight of your exhaust system to sacrifice for a few decibel lower in sound?

 

The TI that i have is so LOUD with test pipe. With the muffler in place of tesr pipe seem to quite down a lot

 

Which muffler are you using?

 

Here is some exhaust info if you care to read: http://www.vaglinks.com/Docs/Misc/Mu...t_Section3.pdf

 

nice work!

 

i love the OP's original exhaust i think its honestly a perfect balance of sound/quiet. good job for doing all the guess work on what works to quiet it all down.

 

+2 Very quiet

 

Thanks for the info but yes I wouldnt mind increasing the weight a little.

I have the buschur 3" downpipe which is a weight saver right there. And then I dont have the the stock cat but a muffler will be in its replacement, another weight saver. I think I will go with a dual 2.25" piping. The addition of a dual 2.25" will probably weight more than a 3" probably same if not less than the stock exhaust. So in the end although I will be weighting more than a 3" setup, I would be same if not less than a complete stock turbo back exhaust.

Thats pretty nice how you got a widebody to fit in there. I wasnt sure if it would fit but looks like it did. Is that 9" wide body?

Thanks for the interesting find. Seem like the widebody compared to a 6" dia 14" long round makes about 1 db peak difference at 240hz. I wonder then what would happen if it was a 7" dia round muffler. Just from an assumption point of view the 7" round like Buschur uses would quiet better.

Thanks for the kind words guys. But one thing the video/sound I posted doesnt show that clearly is the bass. Its still on the deep side and I wont to make it less deep sounding. Actually I want it to sound more like like a high revving high compression motor or maybe even like this b5 S4 : http://www.youtube.com/watch?v=P9g9l8dMnAc

Love how that s4 makes a prrr's . I understand we have totally 2 different engines but maybe I can manipulate the exhaust waves to change the tone.


Also another way to look at it. Larger diameter pipe = deeper sound with lower frequency maybe split into dual smaller diameter piping I'd get higher frequency higher pitch sound. And with 2 mufflers deaden the sound more and especially with one muffler having an crossover inside.

I have no data to back any of this up, just gathering some info here and there, common sense, very slight physics and a lot of guessing with a touch of hopes and dreams.

 

I'm no engineer, but I don't think dual 2.25" pipes are not going to flow as well as a single 3". Cross-sectional area aside, you have to consider the frictional losses with the increased surface area of the pipes.

 

It's a Magnaflow 3" had to cut inlet and outlet a little bit

 

Well the increase in friction could have some good effects as well. They could keep the exhaust gas hotter = faster.


Is that a 14LX9WX5H case?

 

Don't think so. If anything, the heat is going to be bled off through the increased surface area. Think of the way rear mount turbo kits just use super long IC pipes in place of an actual intercooler.