I was trying to trouble shoot my SES for 5 months. Finally tried removing the wool. So far so good.

CEL fixed. The steel wool was overkill.
The graphite gasket was replaced with high temp gasket maker so it doesn't oxidize.
The rattle was fixed with the addition of the bracket.

As for sound it depends on what exhaust system it is connected to but in every case regardless of what it is connected to, the ART pipes are much quieter than regular resonated test pipes.

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.

Great to hear :tup:

Can't wait to see/hear the final results :tup:

Gratz!!

No true dual Exhaust (2.5") for twin turbo families?? :(

cant wait to hear it!

Its a hybrid of dual 2.5 and dual 3.0". And trust me, its far better for the turbo dyno curve.

I've seen what all dual 2.5" does and what all dual 3.0" does and neither provides the best overall performance in the 400HP-650HP range. They each have their compromises.

Having the 2.5" primaries on the XYZ tremendously helps the midrange and TQ for FI applications. I won't recommend 3" primaries unless you go to really high power. 700+HP.
Having the dual 3" past the collector provides the best HP.

It would have been cheaper and easier to manufacture the system all out of the same diameter tubing from front to back but that doesn't provide the best results on the dyno.


Having a progressively larger and larger diameter on the exhaust provides the best power results. FI or NA.

2.25" on the ART pipes.
Expanded to dual 2.5" on the XYZ primaries.
Expanded to dual 3.0" after the merge collector.


Small diameter pipes close to the engine increases scavenging but as the exhaust gas flows further and further away from the engine, scavenging has diminishing returns. Eventually it gets to the point where small diameter starts to create more pressure drop than scavenging and that kills HP.

It can't be too large and it cant be too small and it all depends on location.

That is why this exhaust has continually increasing flow area from front to back.
It dynos better this way.... and it sounds better too.

In for video/sound clip!

+1, might be time for a new exhaust.

x2!

Looks like you're just about ready to make a new thread dedicated to the new exhaust!!

Yeehaw!

^^ I agree.

My M370 and ART pipes are treating me well...I'm tempted to jump on a full motordyne train if the price is right :)

I just finished my third "fix". Now I removed the gaskets entirely and used only RTV so we'll see how that goes. I haven't yet removed the steel wool because my car was tuned with the steel wool so I'm confident my CEL is coming from the leak only.

When you put together a press release could you please expand on these a bit? It seems like you can mix and match, so it would be nice to know the pros/cons of each combination.