Motordyne ART Pipes (TEST Pipes w/ a twisty twist)

[tollboothwilley]

Take a look if you haven't yet...

http://www.motordyneengineerin...d=121

Some serious gains over normal test pipes and of course over stock.

[RED_DET]

What are the gains, I don't see any info?

[tollboothwilley]

In my early days as a rocket scientist designing the R-4D-16 dual mode rocket engine for JPL there were all kinds of challenges in ensuring the performance and reliability of our rocket engines.

One of the greatest challenges was designing an injector to produce smooth and stable combustion of the fuel and oxidizer in the combustion chamber. There were occasionally these acoustic instabilities (tangential modes) in the combustion chamber that could be excited and start a run away condition that could quickly destroy the engine. To address this problem I used Helmholtz resonators inside the rocket engine to damp out the acoustic tangential modes. A tangential mode is basically a shockwave that would spin around the inner circumference of the combustion chamber analogous to a supersonic tornado at 20K Hz. Not unlike detonation, this tangential mode would scrub off the boundary layer, radically increase the heat transfer into the chamber walls and result in a catastrophic failure.

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 shockwave.

The R-4D-16 rocket engine design was (is) very successful and is being used by nearly every branch of the US military for Hydrazine / Nitrogen tetroxide liquid bi-propellant propellant systems. Many are in space flight now.

I co-authored a paper on the rocket engine and submitted it to the American Institute of Aeronautics and Astronautics (AIAA). The paper was published and ended up winning "Best Propulsion Paper of the Year" at the 2001 AIAA Joint Propulsion Conference. After studying the application of Helmholtz resonators in depth I began to see how they could be used in a range of different applications. Particularly in automotive. If you have ever studied the science/art of header design it becomes clear that it is all about the interaction of acoustics and engine dynamics. Headers are a way of resonance tuning acoustics to the engine.

By this same reasoning, a Helmholtz resonator could be designed to operate in phase or out of phase with the engine at any given RPM. By transferring the science of rocket propulsion based Helmholtz resonators to the automotive sciences, Advanced Resonance Tuning can be made to enhance performance on essentially any kind of reciprocating engine.

These can be used on a fully modified exhaust system to make additional power. Traditionally, if you already have an intake mod, 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. :biggthumpup:

This is Motordyne's debut of the patent pending <FONT SIZE=""3"">Advanced Resonance Tuning</FONT> <FONT SIZE=""1"">(TM)</FONT>. ART is a new way of enhancing the power curve on any engine.

They're not headers. They're not test pipes. They're ART pipes!

$660/pair



Dyno testing shows a very usable 5-6 HP (or ~50%) improvement over regular test pipes. A clear improvement for the road course racing power band. 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.

Although these ART pipes are designed and tuned for power they happen have a very pleasing effect on the sound. I normally prefer to let independent dyno testing define the performance but I knew you would really want to see this.

Let the independent reviews begin!

[LuckyLuke]

Is it street legal?

[tollboothwilley]

not in california...no test pipes are street legal in CA

[Joey666Crack]

I can only assume they are not legal in any state that requires hydrocarbon testing.

[tollboothwilley]

Some states vary from county to county. You can pass emissions testing with some fooling as long as they don't do a visual/sniffer test.

[pae9132]

anybody else running these yet? seems like they were forgotten about on here but it seems like such a great mod. i'm putting mine on this weekend!

[tollboothwilley]

let us know your thoughts. every person I have seen that has them posts great reviews.

I wish I didnt have HFC already...or else I would have gone for these. They make the exhaust sound crazy exotic too.

[awdjdmtalon]

For those that keep asking. These are not street legal. It is illegal to remove a functioning emission device. Replacing your converters with these is the same as replacing them with test pipes.

[pae9132]

well i have had these in a few days now and the difference is amazing....i dont have a before and after dyno but it feels like a completely different car...and it sounds great...no rasp....i DID have test pipes (titek) and these blow those away.....

[jmcole13]

Whats this so to the engine lights? i have an 09 g37x and i dont want to void warranty/ turn on lights?

[pae9132]

they have not thrown a CEL for me or for anyone else that I have read a review from...