MotorDyne Advanced Resonance Tuning Test Pipes - Tech - Modified Magazine

Test Mule
'10 Infiniti G37 6-speed manual
Engine 3.7-liter VQ37DE DOHC 24-valve V-6
Relevant Mods Stock.

Key Features
»Pipes alter exhaust harmonics for more performance and better sound
»Increase power without increasing noise
»Reduce rasp and droning that's commonly associated with test pipes and high-flow cats
»Replace factory catalytic converters and fit like stock

Proving Grounds
Resonance tuning - sounds like a bit of a gimmick when you first read it, huh? Air flowing through exhaust piping is all headed one way, and from what we've all come to know, the faster you can get it out the exhaust pipe the better. If that truly is the case, then welding on some tubes to the side of some test pipes seems a bit counterintuitive, but there's a lot more going on with the exhaust gases and pressure than most of us realize. Thankfully, someone by the name of Tony Collette, owner of Motordyne, has spent countless hours doing all the hard work and calculations for us to figure out that adding resonance chambers to normal test pipes will actually increases exhaust gas scavenging and power output. The Motordyne Advanced Resonance Tuning pipes work by altering the exhaust harmonics flowing through them by adding side chambers. These chambers also affect the sound output in a good way. Most test pipes add significant amount of noise, and on Z and G cars, they produce a lot of part throttle drone and raspiness. The ART pipes help eliminate those rather annoying byproducts, without sacrificing any of the power.

Results
Sean Church, owner of Church Automotive Testing, decided his brand-new Infiniti G37 needed some more power, and Motordyne's ART pipes would be the perfect bolt-on to unlock some horsepower while keeping the car sounding showroom stock.

The G37 shares the same powerplant as the 370Z, so it's already an impressive performer right out of the box, thanks due in part to Nissan wringing out nearly every last horsepower out of the 3.7-liter engine. Because of its efficient nature, making power with bolt-ons isn't as easy on this motor as with others, so it was doubtful if we would see the large power gains that Motordyne claims (15-20 ft-lbs). However, the ART pipes have been tested many time on the VQ35DE engine with great results so we knew they could perform - it was just a question of how well.

If you don't have a hoist to perform the installation on, then be prepared to curse and swear your heart out because of the cramped nature of the exhaust piping underneath the G37.

Getting to the three bolts that hold the factory catalytic converter to the header is a massive headache and requires lots of extensions and a swivel joint or two. Once off, the ART pipes provide for some more wiggle room, making for a quick install.

You don't have to worry about check-engine lights that are almost always triggered with the removal of catalytic converters because the ART pipes have extended bungs that move the 02 sensors from being in direct contact with the exhaust path. After checking for exhaust leaks, the G37 was bolted up to Church's Dynapack dyno, and after a few runs, the results were consistent enough to draw a conclusion. With the ART pipes and Sean's tuning, the G37 picked up 15 peak whp and 7 peak ft-lbs of torque. The dyno chart shows a nice gain throughout the entire rpm torque band and on the horsepower side, as the rpm climb so does the power. Sean also did a stock (no ECU tune or ART pipes) pull that resulted in 308 whp and 264 ft-lbs, which if you add tuning and ART pipes to the bone-stock G37, the result is a healthy 28 whp and 14 ft-lbs gain. That's not too shabby at all considering the excellent factory output of the VQ37DE.

On the street, the exhaust note is just slightly altered, nothing that any suspecting officer would pick up, though. There's no drone or resonance, either, so the power gains come with no ill sound effects, and the engine pulls extremely hard all the way to redline. All of a sudden, this G37 sedan is much faster than it looks, and more importantly, it's a blast to drive.

Art Pipes + Church ECU Tune
Gains Made
+ 15.2 whp
+ 7.2 ft-lbs tq
Before: 320.9 whp & 270.6 ft-lbs tq
After: 336.1 whp & 277.8 ft-lbs tq