Project G37 Sedan Fast Intentions Exhaust

Project Infiniti G37S: Part 3: Fast Intentions High Flow Resonated Cats and Exhaust

by Aaron LaBeau

Exhaust upgrades have been a huge disappointment for me over the years.  I can say without a doubt that the dollar to satisfaction has to be the worst or greatest depending on how you like measuring disappointment.  I’ve either had exhaust’s that sound great but make no power or make power but beat your eardrums to death with droning at cruising speeds on the highway.

As listed on the product info sheet all flanges are welded on the inside and port and polished (shown below).

After pouring over forums and websites the only company I kept seeing the words ‘you won’t regret it’ for the G37 was with Fast Intentions.  While there are others in this market that make a great product it seems with exhausts you need to make the choice of compromising comfort in terms of interior noise for that last bit of horsepower.

Behind the scenes at Fast Intentions for the exhaust assembly.  As true craftsmen they take their time and as such this kind of work takes time.  From order to delivery was a 6 week process but delivered in that timeframe as promised.

Fast Intentions hand builds all of their exhaust systems in house at their shop in Simi Valley, CA. Stating that their cat back exhaust system is the ‘premier upgrade for all G35/37 owners’ they are effectively throwing down the mic.  Their goal with this system was to enhance the sound that Infiniti created from the factory by making the exhaust note deeper, smoother and louder.

Their X-pipe is designed to increase low end torque and maximize power throughout the entire RPM band.  The exhaust note is quiet at idle but people will know the car is modified.  Startup now has its own unique growl, skip to the end of the article if you must.  At wide open throttle it really comes to life in an aggressive way without being abusive to the ears.  When it came down to ordering the exhaust I was impressed by all the options available and considerations Fast Intentions made for the G owner.

Fast Intentions offer variations between manual and automatic and RWD or AWD in their options having to do with the various pipe shapes and sizes as the exhaust is routed.  An option of 2.5” piping over their standard 2.25” piping for forced induction applications is also available.  Finally, and most importantly, their X-pipe is offered straight through, or with 12” or 18” resonators.  For those of us who daily drive our cars this last option is super important.  Eyeballing the comparison between the stock exhaust and the FI exhaust it looks like they kept the resonator as close to the factory location as possible.  Infiniti certainly did their homework in terms of reducing NVH and FI smartly followed this template while increasing exhaust flow.  The FI system is a true dual exhaust system unlike the original Infiniti exhaust that merges 2-1 and then splits back out to dual at the factory X-pipe.

The stock exhaust while comfortably quiet; didn’t have the performance sound we wanted so off it went.


  1. in the videos were the cars non resonated or 18in resonator, im looking to buy one and am just concerned the 18inch resonator will be to quiet and the non resonator will have to much drone and lose the deep sound. if you could get back to me thatd be great thanks.

  2. We got the 18″ resonators on the 2.25″ exhaust. The resonators are shown on page 2 of the article. I love the exhaust. It’s quiet enough when I’m cruising around on surface streets or on the highway but there’s nothing quiet about it once your over 4k RPM’s. On cold startup my neighbors definitely hear the car. It’s the perfect compromise in my opinion compared to other louder exhausts that sound great when you’ve got your foot stuffed on the go fast pedal but make you hate the car when you’re just driving normally.

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