Advanced Resonance Tuning (ART pipes)
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MOTORDYNE-MY350Z SPONSOR
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In my days as a rocket scientist at Marquardt designing rocket engines for JPL there were many challenges in ensuring the performance and reliability of the rocket engines.
One of the greatest challenges was designing an injector that could produce smooth and stable combustion in the combustion chamber. There were occasionally these acoustic resonances (tangential modes) in the combustion chamber that could start a run away condition where it could quickly destroy the engine. To address this problem we used Helmholtz resonators inside the engine to damp out the tangential acoustic resonances. A tangential resonance was a shockwave that would spin like a tornado inside the combustion chamber at 20K Hz. Much like ping or detonation in a internal combustion engine, this tangential mode would scrub off the boundary layer and radically increase the heat transfer into the chamber walls and result in the engine overheating.
Helmholtz resonators were the solution to these tangential waves. By properly tuning the Helmholtz resonator to the frequency of the tangential mode you could either magnify or eliminate the destructive shockwave.
After studying the application of Helmholtz resonators in depth I began to see how they could be used in a range of applications other than rocket propulsion. Particularly in automotive.
If you have studied header design it is clear their function is all about using exhaust acoustics to increase scavenging. ART pipes do the same thing but in a different way. Headers use 1/4 wave resonators to make power. ART pipes use Helmholtz resonators to make power.
Traditionally, if you already have an intake, headers, test pipes with a full catback exhaust and tune, that was the end of the line. There was no more left to gain. ...But not any more.
This is Motordyne's debut of the patent pending Advanced Resonance Tuning (TM).
The plot below is without exhaust cam phase tuning. The ART pipes respond very well to cam tuning.








Regular test pipes always result in a large loss of low end torque. Compared to test pipes, the ART pipes produce a large gain in low end torque that is clearly felt and can be very usable for auto-cross or powerful launches in drag racing.

The plot below is a Horse Power comparison of ART pipes Vs Stock catalytic converters.

The plot below is a Torque comparison of ART pipes Vs Stock catalytic converters.
One of the greatest challenges was designing an injector that could produce smooth and stable combustion in the combustion chamber. There were occasionally these acoustic resonances (tangential modes) in the combustion chamber that could start a run away condition where it could quickly destroy the engine. To address this problem we used Helmholtz resonators inside the engine to damp out the tangential acoustic resonances. A tangential resonance was a shockwave that would spin like a tornado inside the combustion chamber at 20K Hz. Much like ping or detonation in a internal combustion engine, this tangential mode would scrub off the boundary layer and radically increase the heat transfer into the chamber walls and result in the engine overheating.
Helmholtz resonators were the solution to these tangential waves. By properly tuning the Helmholtz resonator to the frequency of the tangential mode you could either magnify or eliminate the destructive shockwave.
After studying the application of Helmholtz resonators in depth I began to see how they could be used in a range of applications other than rocket propulsion. Particularly in automotive.
If you have studied header design it is clear their function is all about using exhaust acoustics to increase scavenging. ART pipes do the same thing but in a different way. Headers use 1/4 wave resonators to make power. ART pipes use Helmholtz resonators to make power. Traditionally, if you already have an intake, headers, test pipes with a full catback exhaust and tune, that was the end of the line. There was no more left to gain. ...But not any more.
This is Motordyne's debut of the patent pending Advanced Resonance Tuning (TM).
The plot below is without exhaust cam phase tuning. The ART pipes respond very well to cam tuning.









Regular test pipes always result in a large loss of low end torque. Compared to test pipes, the ART pipes produce a large gain in low end torque that is clearly felt and can be very usable for auto-cross or powerful launches in drag racing.

The plot below is a Horse Power comparison of ART pipes Vs Stock catalytic converters.

The plot below is a Torque comparison of ART pipes Vs Stock catalytic converters.
Last edited by Hydrazine; Nov 30, 2012 at 10:02 AM. Reason: updated
Thread Starter
MOTORDYNE-MY350Z SPONSOR
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EDIT: Dynos!
Onagao
https://my350z.com/forum/intake-exhaust/476102-independent-review-motordyne-art-pipes.html
Arnold K
https://my350z.com/forum/intake-exhaust/481447-art-pipes-installed-review-thread.html
Silencer 0
https://my350z.com/forum/intake-exhaust/477389-independent-review-of-motordynes-art-pipes.html
Clark Crawford
https://my350z.com/forum/intake-exhaust/484271-art-pipe-z1-pipe-dyno-comparison-race-car.html
https://my350z.com/forum/intake-exhaust/483977-art-pipes-test-pipe-dyno-comparison.html
James
https://my350z.com/forum/intake-exhaust/503150-motordyne-shockwave-art-317-hp-272tq-to-the-wheels.html
<o>Dark9T Dynos
</o>https://my350z.com/forum/intake-exha...g-307-8hp.html
Rubidium Dynos
https://my350z.com/forum/9411380-post623.html
https://my350z.com/forum/intake-exha...-pipes-32.html
<o>
</o>
Onagao
https://my350z.com/forum/intake-exhaust/476102-independent-review-motordyne-art-pipes.html
Arnold K
https://my350z.com/forum/intake-exhaust/481447-art-pipes-installed-review-thread.html
Silencer 0
https://my350z.com/forum/intake-exhaust/477389-independent-review-of-motordynes-art-pipes.html
Clark Crawford
https://my350z.com/forum/intake-exhaust/484271-art-pipe-z1-pipe-dyno-comparison-race-car.html
https://my350z.com/forum/intake-exhaust/483977-art-pipes-test-pipe-dyno-comparison.html
James
https://my350z.com/forum/intake-exhaust/503150-motordyne-shockwave-art-317-hp-272tq-to-the-wheels.html
<o>Dark9T Dynos
</o>https://my350z.com/forum/intake-exha...g-307-8hp.html
Rubidium Dynos
https://my350z.com/forum/9411380-post623.html
https://my350z.com/forum/intake-exha...-pipes-32.html
<o>
</o>
Last edited by Hydrazine; Oct 13, 2011 at 08:36 PM. Reason: Dark9T Dyno
Let me be the first to post: extraordinary!
Looking forward to the independent dynos. I cannot believe there is that much torque down low to be had over test pipes. 
I am sorely disappointed that I cannot take advantage to see what this would do on a FI setup (because of my custom 3.5" piping)...
Looking forward to the independent dynos. I cannot believe there is that much torque down low to be had over test pipes. 
I am sorely disappointed that I cannot take advantage to see what this would do on a FI setup (because of my custom 3.5" piping)...
Last edited by rcdash; Feb 9, 2010 at 07:32 PM.
Very interesting, I studied this concept a while back when working for an exhaust company and was actually explaining it on another forum just a couple days ago.
What car/engine/mod combination were these tested on to yeild the gains shown?
What car/engine/mod combination were these tested on to yeild the gains shown?
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Well done!
i would love to hear what they sound like on the car they look very interesting when will they be available for sale i don't see them on your website what would the cost be on them also
Thread Starter
MOTORDYNE-MY350Z SPONSOR
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They are significantly quieter than regular test pipes and they cut drone. They also add a very, very deep, but subtle, harmonic to the sound. The note is so deep, its approaching infrasonic.
wow they look sick, i am actually looking for test pipes/HFC for my 06 rev-up. I got AAM y-pipe w/ agency power exhaust. what is the pipping becuase my y-pipe goes from 2.5 to 3 inches. Will these pipes throw check engine lights?




