Based on the discussion in this thread, Chase, I think you should probably just add some turbos. :tup:

Bringing up the GTR exhaust again, just as an example. It has two sets of cats and a "Y" pipe, etc... Hell, if it takes this much engineering to reduce the sound, just remove the SC. You built a race car and it comes with a certain decibal level... LOL

https://farm3.staticflickr.com/2867/...77688f_z_d.jpg

Sound level. Didn't notice any difference in power/boost at all.

Jeez, for those prices you might as well just buy another whole system! :confused:

I've got 2 Vibrant GESI 7530's. They are placed at the end of the downpipes close to the flange.

It hurt the wallet but I'm hoping to not have to replace these. Sounds good with a 3" exhaust, etc.

Sounds good. Send me yours :tup:

I built this a long time ago for my 350Z:

http://i137.photobucket.com/albums/q...ps38034bdd.jpg

http://i137.photobucket.com/albums/q...ps1df5f7db.jpg

http://i137.photobucket.com/albums/q...ps6b092cbd.jpg

The two mufflers in the rear were very large straight flow through design, and for that reason along with the turbo, the exhaust was as quiet as stock. This is with aftermarket equal length headers, and of course no catalytic converters.

I have since built this:

http://i137.photobucket.com/albums/q...pslijhbqjm.jpg


3.5" piping from where the OEM Y-pipe would end, splitting in to dual 3". This is all aluminium, and weighs in at 12lbs. It is of course louder, but not as loud as one would think.

Also did a single 3.5", which is a bit more rowdy :) it came in at about 8lbs :

http://i137.photobucket.com/albums/q...pscmtlm5ad.jpg

http://i137.photobucket.com/albums/q...ps1kc9x1em.jpg


Sound clip of the single 3.5" splitting in to dual 3.0"

http://vid137.photobucket.com/albums...psueffzhrq.mp4

Sound clip while on the lift single 3.5":

http://vid137.photobucket.com/albums...pscleukp0r.mp4

Love that first one, any clips of that one?

And for the size I was expecting a lot more noise for those last two. Nice work!

I'm waiting to finish rebuilding my SC, before I do another recording under the same circumstances of my pre-SC recordings for a reasonable comparison. Right now the car starts, but the SC is on my bench awaiting new seals & bearings hah.

Sorry, don't have sounds clips of the first one. It is basically stock sounding. With that exhaust, all you hear is the turbo.

Ditto. Got my new seals and bearings here just need to get to the R&R.

Maybe I need a 3" test pipe instead of 2.5

Or bring my car up a couple days before seb's dyno day in June and you can whip me up an exhaust like that one..

Dang Sasha. You should start a BP exhaust option with your kits, or others. Those look great!

For sure, I'd be able to help you with that.

Go full aluminium once you are out of the heat range of the turbo, I really like the tone on my own car. Dual 3" with 4 mufflers.

I also use 3mm wall aluminium tubing on the exhaust, not the typical Vibrant paper thing crap. It will last a very long time.


Yeah, I had a bit of a feeler for the aluminium exhaust, but there wasn't all that much interest.

But then my car will be too loud!

I thought I was understanding that the consensus leans towards turbos being generally quieter than s/c (although depending upon a host of variables), but in this thread it seems that turbo and s/c exhaust systems are being compared interchangeably.

If there IS a difference in sound levels between the two systems, how can the s/c exhaust be modified to reduce some of this additional noise? Maybe I'm in the minority, but I'd like to see some configuration that keeps the decibels to a manageable level. Seems like the cats are a key component to reduce some of the worst of the noise, but they should be repositioned downstream to avoid the worst of the heat? Is that right? Where would you place hangers, etc.? Will the sensors need additional cabling to reach? Other problems?

I found a suggestion on one website that recommended adding spiral inserts inside straight pipes to reduce excessive noise. Has anyone tried something like this?

I tried Googling the images of the exhausts of factory s/c cars, but that didn't really yield helpful results. Are factory s/c cars known to burn through cats?

There is definitely a difference in noise having turbos in the exhaust stream and its a very significant one. Exhaust sound, heat, velocity... energy in general, are soaked up by the turbo.

There is a lot of good discussion on this thread.. but for the sake of discussion we've probably overthought it quite a bit (which is healthy as it helps us all gain more knowledge....one of the primary purposes of this forum!)... I think if you just go with one of the quieter exhaust systems that follow the OEM design (allows for much larger muffler) and some resonated test pipes (or cats somewhere in the stream), you'll be fine.