I'm going to ask about the ultimate exhaust system, even though the site rules clearly state that there isn't one. I hope I can sneak this thread past the moderators.
One of the things that came out of my recent L6 turbo engine build, is that I really don't like the sound of my exhaust. This was once a track only car, and now it's going to get more street duty, so a change needs to be made to quiet it down. At the same time, I am planning on going full stainless and building the last exhaust this car will ever need.
Right now the car sounds like a glorified motorboat. (or Subaru) The current exhaust comes out of the turbo into a 2.5" mandrel bent downpipe, transitions to 3" and runs through a 3" round magnaflow (straight through) muffler. I've got about a 6" long tip on the muffler to route gases away from the rear of the car. It's loud, it's raw, it's fine for the car as a race car.
Video with current exhaust sound:
As a street car, I want to achieve something a little more exotic sounding, as well as quieter. For example:
I believe in order to achieve the sound I want, I am going to need to run dual functional tail pipes. I think running a different length to each side will create the harmonized sound I am looking for.
In my mind the system plays out like this:
2.5" mandrel bent downpipe off of the turbo
Custom SS "Y" from 2.5" to dual 2.25"
Dual 2.25" each into a 12" long resonator box in the tranny tunnel
One 2.25" pipe exits at the outside face of the box
One 2.25" pipe exits 8" into the box, making this path a different length than the other
[*]2.25" pipe runs to the back of the car, one exit on each side, each through a muffler.
[*]Dual tip exits from each muffler.
My rationale is that the staggered exit from the resonator box will allow the same pulse to split and reach the tailpipes at different times, therefore smoothing out the exhaust note to a degree.
By running 2 larger mufflers (than the current 1 smallish muffler) I should be able to control the volume a bit better.
The dual tips are more for show, but if I can stagger the paths between the muffler and each of it's tips, more smoothness should ensue.
Dual 2.25" is effectively larger than the 3" single I have now, and probably easier to package under the car as well.
I might be way off base with these assumptions, but I welcome any input those with experience on exhaust tuning or exhaust design may be willing to share.