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Spectre Air Intake for the Jeep Grand Cherokee SRT8 6.4L 392 Hemi Adds Horsepower

Jeep Grand Cherokee SRT with Spectre Air Intake

Jeep Grand Cherokee SRT with Spectre Air Intake

The fourth generation WKZ Grand Cherokee is an authentic luxury vehicle that can take you to the country club, or up the side of a mountain. Thanks to some serious off road hardware, and its classy wood and leather veneer, this multi-function SUV can adapt to nearly any terrain or social setting. The 2012-2015 Jeep Grand Cherokee SRT8 on the other hand, looks, sounds and acts like a hooligan, no matter where you take it. To fit into the Jeep family, It's got a nice interior, some fancy gadgets, and a Selec-Trac AWD system. But this ballistic brick was designed to conquer the street, not the "great outdoors". In a straight line, the Grand Cherokee SRT can scamper to 60 mph in the mid-4 second range, and it has a top speed in excess of 150 mph. All of this ferocious velocity comes courtesy of a 6.4L / 392 Hemi V8, which pumps out a staggering 470-hp/475-hp (depending on the model year). However if you're reading this, you man have one of these blacked-out monsters sitting in your driveway. So let's cut the chit-chat, and talk about how a Spectre Cold Air Intake System can add even more horsepower and torque to your 392 Hemi.

Spectre Air Intake 9039

Spectre Air Intake 9039

Most engines have triangular heads and flat-top Pistons. The 6.4 liter Hemi engine has hemispherical shaped heads (hence the name "Hemi") with two spark plugs at the top, and huge valves on either side of the 'dome'. The top of the pistons are also dome shaped, so when it rises to compress to air/fuel mixture before detonation, that unique head/piston shape enables more pressure to build. Once the spark plugs ignite the pressurized fuel/air mix, more of the heat generated by the explosion stays inside the 'Hemi dome', which helps the fuel to burn more completely. This increased combustion efficiency allows the 392 Hemi in your Grand Cherokee SRT to create more power than similarly sized engines.

Those huge intake valves also help to improve horsepower output, because their size and precise location allow the air to swirl into cylinder, which helps the fuel and air mix to combine more thoroughly. One of the most effective ways to increase the horsepower in your Jeep Grand Cherokee 6.4L, is to lower the intake air temperature. You may already know that cold air causes fuel to burn hotter, due to its additional oxygen molecules. So the Spectre 9039 Cold Air Intake System is designed to collect and deliver a higher volume of cold, oxygen-rich air.

Engine Bay with Spectre Air Intake 9039

Engine Bay with Spectre Air Intake 9039

The factory intake on a 2012-2015 Jeep Grand Cherokee SRT8 collects air through a small hole at the bottom of the airbox, then forces it through a thick, surface-loading paper filter (dirt collects on the surface, often impeding airflow), and into a narrow plastic intake tube. As the air travels over the uneven surfaces inside the tube, it becomes turbulent, which causes it to heat up and loose some of its potency. The Spectre 9039 Cold Air Intake System does away with these power-robbing parts, and creates a smoother, more direct airflow path. To do this, the stock air box is replaced by an oversized high-flow Spectre Performance Air Filter. This reusable synthetic air filter is shielded from the hot engine bay air by a powder coated aluminum heat shield that uses a special rubber gasket to seal against the underside of the hood.

Once air passes through the depth-loading Spectre air filter, it flows to the engine through a large-diameter polished aluminum intake, which has smooth interior surfaces and mandrel-bent curves. This helps to straighten the airflow path, and significantly reduces air turbulence. The Spectre 9039 intake tube also has a fitting for the stock Hemi 6.4L Intake Air Temperature Sensor, so you won't have to make any fitment, or ECU software modifications. Thanks to it's carefully engineered design, the plug-and-play Spectre 9039 Cold Air Intake System can be installed in around 90 minutes, using just a few wrenches and sockets.

Features & Benefits of the Spectre 9039 Cold Air Intake System

  • Developed exclusively for the 2012-2015 Jeep Grand Cherokee SRT8
  • Increases horsepower & torque
  • Provides better throttle response
  • Improves engine sound
  • Aluminum intake tube reduces airflow restrictions and comes plumbed for factory IAT sensor
  • Reusable synthetic Spectre performance air filter
  • Designed to replace entire OEM air intake system
  • No modifications or ECU programming required
  • Entire system can be installed in about 90 minutes using simple hand tools

Spectre 9039 Air Intake Kit will fit the following vehicles:

Find all Spectre Jeep Grand Cherokee Air Intakes at If you're ready to get even more horsepower and torque from your 2012-2015 Jeep Grand Cherokee SRT8, then a Spectre 9039 Cold Air Intake System is what you want. In addition to this cold air intake system, we also have an entire catalog of performance parts for your Jeep Grand Cherokee SRT / SRT8. To check it all out, use the Search by Vehicle tool, or find a Spectre Performance dealer near you.

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