Great news on the exhaust.
After fabricating prototype, after prototype, after prototype and testing every single one of them on the street and the dyno I finally came up with a configuration that is a superior design than the 350Z TDX2 system.
There were many new concepts tested. Some were wildly different using side helmholtz sidebranch resonators exclusively. Most of which didn't pass the sound quality test.... but with enough experimentation I began to see the patterns of what the 370 liked and didn't like.
What I did find is that much of what I already figured out in prior development testing still held true but just required a little modification.
The different merge collectors at different merge angles and merge distances from the engine. All re-mapped and dyno tested on the 370. ...The results were the same as what I found before.
Total merging of the exhaust gases merged at the proper angle and merged close to the engine (but not too close). So once again, the XYZ pipe is a critical element to optimum power and sound. What is different now is the XYZ module line up has 2 new options.
1) Straight pipe module
2) Resonator module
3) HFC module
and now
4) A new muffler module
5) A new muffler module with a built in HFC.
The new 370Z exhaust configuration is slightly quieter than its predecessor the TDX2 for normal everyday daily driving but it really lights up at high RPM WOT. And its not just loud, its sounds excellent when loud. So I would sum this one up as having a more progressive sound than the TDX2. Quieter at low RPM yet louder at high RPM.
I like this one.
I am going to do one more set of tweaks to the muffler to do a little more experimentation on the sound but either way, it will either be the one I have on the car now or a slightly quieter muffler.
This has been an exceptionally long, costly and challenging development project but it came through. All prototype experimentation will be concluded Tuesday.