Repost from NAGTROC - Armytrix Valvetronic Exhaust - I took the plunge!
 

Here is the review from one of our customers purchased Armytrix GT-R R35 Cat-back Valvetronic Exhaust

What the full set sounds like..?
Nissan GT-R R35 with ARMYTRIX cat-back exhaust, Start-Up, Revving, Acceleration - exhaust SYMPHONY! - YouTube

Original post: http://www.gtrlife.com/forums/topic/89028-armytrix-valvetronic-exhaust-i-took-the-plunge/
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Hi folks, I’ve been debating a variable volume exhaust for the last little while and finally decided to bite the bullet. I perused the usual suspects - Agency Power and AAM - and they both make quality pieces, but I was quite intrigued by MEGTROC Admin ‘Q’s post about Armytrix. I checked out their youtube clips and website (www.armytrix.com), and after speaking with them on multiple occasions, I decided to take the plunge on their variable volume catback exhaust.

As a complete set they offer catless downpipes, a resonated catless midpipe, and the variable volume exhaust. Given that I already have GTC cast iron downpipes, and a Cobb catted midpipe (I can’t stand the smell otherwise), I decided to go with the variable volume exhaust alone. I know a lot of you run similar bolt-on setups either with or without a catted midpipe.

It’s remote controlled with hydraulic actuators, and what I like about it is that irrespective of whether the valve is open or closed, it flows through all 4 tailpipes (you can see in the photos below). Also, you can select open, closed, or have it automatically open at a set RPM level, which I think is a useful feature.

I ordered it from them on August 12th, and it arrived August 13th. Yeah, that was pretty darn awesome.

I’ve taken some pictures of it sitting in my living room (forgive the rug) and will take more pictures and videos/sound clips when I have it installed this Wednesday. I'll give a full review of the exhaust sound and performance once I have it on there, so hopefully it’ll be helpful for others considering variable exhausts as well.

https://www.6speedonline.com/forums/...ine=1396243254
https://www.6speedonline.com/forums/...ine=1396243254
https://www.6speedonline.com/forums/...ine=1396243254
https://www.6speedonline.com/forums/...ine=1396243254
https://www.6speedonline.com/forums/...ine=1396243254
https://www.6speedonline.com/forums/...ine=1396243254
https://www.6speedonline.com/forums/...ine=1396243254
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Hi folks,

Well the exhaust is finally installed, I did it at the local Nissan dealership who did a great job. First impressions are positive! Again, this is with catless GTC downpipes and a Cobb catted non-resonated midpipe. By the way, when I refer to "stock exhaust" below, I mean the stock catback portion along with the aftermarket downpipe/midpipe, and not an entirely stock exhaust.

It's definitely a much different sound than it was before - much more of a lower pitch rumble quality, that extends through the first three or 4000 RPM. It's has a nice growl/rumble to it, a more low frequency "solid" sound, something of a cross between a boxer engine and a V-8 is the best that I can describe it. After that it turns into the typical high-pitched GT-R wail, but with a bit more rumble to it. I found the stock exhaust has more of a boominess across all frequencies and a bit of a drone. To me the Armytrix sounds more "refined". With the exhaust valve is closed, it's definitely quieter than stock, and no drone at either city or highway speeds. It'll definitely keep anyone with sensitive ears happy.

Volume wise, even when open I think it feels a touch quieter than the stock exhaust at lower rpms. That could just be a function of the supression of the louder more "droney" noises. At WOT at higher RPMs it certainly feels as loud if not louder than the stock exhaust. I used to wear earplugs in the car, and now even with the exhaust open, I don't feel the need to. I think it's to do with the "cleaning up" of the frequencies and boominess of the stock exhaust. Overall I'm very happy with the sound. I haven't had a chance yet to try the Auto feature, but will do so tomorrow. The switches seem to work perfectly, it's a vacuum actuator, so hopefully that will bode well for the longevity.

Here are some pics of the installation taken by the mechanic. I'll be doing some videos over the weekend that hopefully will give a better sense of the sound.

https://www.6speedonline.com/forums/...ine=1396243254
https://www.6speedonline.com/forums/...ine=1396243254
https://www.6speedonline.com/forums/...ine=1396243254
https://www.6speedonline.com/forums/...ine=1396243254
https://www.6speedonline.com/forums/...ine=1396243254

Customer video feedback: Armytrix catback valvetronic exhaust revving and flyby exhaust sound! - YouTube