I'm happy to report after 300 miles, my SES codes p2a00 and p2a03 has not returned after taking out the steel wool as suggested by Tony. Hope it remains that way!!

Tony. Is it safe to say the exhausts will not be ready for purchase by Jan 1?

Regarding the wool:

I was forced to do some custom fabrication to my ART Pipes, because they did not come with a bracket. Unfortunately, simply welding a bracket would not suffice, because the J-bung for the O2 sensor hung too low, thus it would not allow the OEM brace that holds the OEM cats to be used. So the bung was cut, angled upward, and rewelded on. I had noticed that the hole that feeds air to the J-bung was so, so sooooo tiny - roughly the size of an ant in width, which explains why ART Pipes can trigger CELs. Seriously, you'd be hard pressed to stick a grain of rice through it. That coupled with the enormous amount of wool stuffed into the bung made it clear why I started getting CELs.

Btw: Performance Motorsport did an absolutely astonishing job with the welding and fabbing. They TIG welded practically everything for me, and all of the cuts, bends, and etc. look damn near factory finish. The vibration in my shifter is now completely gone, and even though I still have a bit of an exhaust leak in the flex area of my exhaust, because there is more rigidity the exhaust leak isn't opening much so the leak has gotten a bit quieter and less annoying. Still, I'm awaiting on my new flex sections - someone from Invidia sent me a pair from a G37 sedan stupidly (they're completely different in size, length, and even design). I was so pissed when we realized it at the shop. And 370Z replacements won't be available for another 2 weeks.

Don't count on it ..

I'm so on the fence regarding the ART pipes. Can I please get some updates as far as CEL's, rattles, leaks and any other concerns that I should be aware of, also what has been done to resolve these issues if there could be a resolution. A big plus would be to hear from anyone that has them with my same exhaust system, sound and performance wise.
Thanks in advance,
TommyGuns

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.

^ Yes, absolutely.
Pictures, descriptions and specs on everything.

New week, new updates?

For some reason I can't get the video to imbed but here is the link.

Motordyne Shockwave exhaust system for the Nissan 370Z. - YouTube

Motordyne Shockwave))) Exhaust with ART test pipes for the Nissan 370Z.
Dynamic range test. Low throttle position 1 minute. Wide Open Throttle 30 seconds.

This is a close stereo mic recording of the exhaust system where high resolution, directional microphones are centered and aimed directly at the tips from 18" away.

You will notice the microphone is sensitive enough to pick up the subtle details such as gravel noise, road texture or even the license plate frame occasionally rattling.

The 370Z starts driving down the road quietly but as soon as it is down shifted and slammed WOT it opens up loudly. No rasp and no drone.

Drive by sound clips will sound substantially different and will be made as soon as the rain stops.:tiphat:

Here you go :tiphat:

Thank you for the imbed tip!:tup:

The clip here is a continuation of the clip above with a lead foot much of the whole way through.

[/QUOTE]

You need some driveby videos. That video doesn't do justice.

Edit: Ok, just now got a chance to watch the videos on my 17" MacBook Pro and they sound soooo much better than the iPhone and iPad that I watched them on 15min ago. However, I still think you need some driveby videos because at WOT it does sound raspy but I think thats due to the mic being right next to the exhaust. I'm sure it sounds 1000x better in person. Can't wait to see dyno comparos for Stock vs Motordyne, AND if you guys did a Fast Intentions vs Motordyne it would be awesome!

Sweet Update Tony! Nice video, quality is pretty sweet and the exhaust system sounds pretty sick. Looking forward to drive by videos and dyno test results! :happydance::happydance:

Think it's time for a new thread!

^this

Tony, are these helmholtz side branch resonators or dual ti straight pipe style? Sounds a bit different than the 350 tdx2...

Production has started as of today 12/12/11
 

Yes, the mic's may be at or near being driven into clipping. The microphones were placed further away on the back window but wind noise became a problem. The only place where wind wasn't a problem was just above the back bumper.

Drivebys will be made ASAP.

I have not made comparative clips or dynos against other manufacturers systems but it will surely happen (independently) once released.

It was a long weekend of testing, swaping, comparing, listening, evaluating and recording.

And here is what I found.

Exhaust system development started on the 370Z with the Shockwave exhaust system. This was the first system.
Then many, many other entirely different configurations were tried. One of the objectives of developing a new exhaust was to try something entirely different and based entirely on Helmholtz side branch resonators for sound control.

The basis for sound control exclusively with side branch resonators was an extrapolation of the effective sound control as seen with ART pipes.
ART pipes are about 1/2 the loudness of regular test pipes so by this reasoning, side branch resonators were tried on an exhaust system using only side branch resonators. This was tried but it was too loud.

Many different variations of Helmholtz sidebranch resonators were tried in different locations and resonator frequencies/sizes.

What I found was sidebranch resonators control act pretty much the same way they affect the power curve. For ART pipes (or side branch resonators) to be effective on the dyno power curve, the resonator must be placed as close as possible to the engine.

As the resonator is placed further and further away from the engine, it has diminishing effect on the power curve.... and the same follows for sound control. Side branch resonators have less effect on sound control as they are placed further and further from the engine.

So while it would have been a very different exhaust system, it just didn't have enough sound control. Many R&D prototype parts and configurations were tried. Forward facing resonators, backward facing resonators, different merge collectors, different resonator locations. I'll post pics of the prototype parts.

It was finally concluded that a glass pack based muffler was mandatory for sufficient sound control and tone. Then multiple variations of glass pack mufflers were tried. A full parametric experimental sequence of tests. All new mufflers and experiments with existing muffler designs by using them in different ways. Forward facing, backward facing, different muffler types and locations. The simple act of flowing a single in dual out glass pack muffler forward or backwards completely changes the sound even though it dynos the same.

Some sounded really good. Some sounded really bad. So more and more prototypes were fabricated and tested. There were 2 good contenders for comparison.

Then finally, another variation was tried on the original 370Z Shockwave exhaust where the muffler was packed more tightly. I found this has the effect of better sound control at lower throttle positions yet makes for a more progressive sound as RPM increases. So it only took a minor change to the muffler packing to achieve the goal.

This system also had the best throttle response

The final result is that the R&D came around full circle. Of all the systems tried the Shockwave))) with a small tweak to the glass packing has the best sound, dyno results and throttle response when all the prototypes were compared side by side.

It took a ton of fabrication time and $$$ but this is the nature of R&D.

Production officially started this morning.
I will start a new thread with pictures when a clean production part comes off the production line.

The Motordyne Shockwave))) exhaust system is modular. The clip above is the loudest variation.
Options will include HFC's built into the midpipes and a full dual 3" version.

Pics will be posted in the new thread.

Nice! :tup:

Tony are you taking volunteers for dyno comparisons?

As many as possible as long as they are fair and independent.

Are there plans for an exhaust for G37?

:yum:

Absolutely.

Cool, nice job. Such a wide variation of sound from light throttle to WOT. I'm interested to hear if the catted version smooths out the sound a bit. It has a very raw sound at WOT, similar to a race car or running open headers or something, which I'm sure many people love. But I'm hoping the catted version sounds a bit more refined.

ps. Do yourselves a favor, people, and stop listening to exhaust clips over a phone or laptop. Those things cant reproduce sound worth a damn.

I think it sounds amazing and I don't hear any rasp at all.

Can't wait for more. Sounds insanely good

I would love to hear the quieter versions of this exhaust.

Agreed- the current clip is a bit loud for my tastes, but the sound/tone itself is very clean.