Mark Houlahan
Tech Editor, Mustang Monthly
August 30, 2012

K&N Engineering AirCharger Intake Kit

PN 63-2578
HP/TQ Gain: 20/26 (tested with air box lid off)
Tuning Required: None

K&N is the grand-daddy of performance air filters and they've been making high-flow filters, induction tubes, EFI filter kits, and more since 1969! Many late-model Mustang owners remember the days of dropping a replacement K&N panel filter into their Fox Mustang while removing the intake silencer and bumping the timing for a nice power boost. Today K&N still offers direct replacement high-flow cleanable filters for just about every Ford ever built, but now offer their 63 Series AirCharger induction kits. The AirCharger features a roto-molded induction tube in black textured plastic that is routed to a sealed air box like the AEM unit shown earlier. The K&N air box features a very slick carbon fiber lid attached with stainless button head fasteners, however there's no way to check the filter's condition unless you remove the lid. K&N also ditches the sound tube so there's no fitting to attach it to the K&N kit, a bummer if you really like the sound tube feeding your passenger compartment its aural delight. Naturally the filter used in the kit is a K&N cotton gauze oiled filter. Lastly, a silicone hose replaces the stock emissions hose for connecting to the induction tube.

To inspect the filter condition in the K&N induction kit you'll need to remove six button head fasteners and the carbon fiber lid to see what your filter looks like. It's a small price to pay to have a completely sealed air tract from the factory snorkel to the throttle body.

Roush Performance Cold Air Intake

PN 420131
HP/TQ Gain: 8-11/7-11
Tuning Required: None

The name Roush is synonymous with latemodel Mustang performance and every Roush Mustang sold includes one of their cold air intake kits designed to work with the stock engine controls or the Roush programming on supercharged Roush Mustangs. The Roush kit gets the nod for the fewest parts as all you'll find in the box is the injection molded heat shield, the injection molded mass air sensor tube, the Roush air filter, and a pair of speed nuts with mounting bolts. The reason being, Roush reuses the stock Ford induction tube, including the emissions and sound tubes as well for a really simple installation. All you have to remove is the factory air box lid and base, bolt in the Roush shield (which seals to the factory cold air snorkel to the grille), bolt in the mass air sensor tube, and slip the air filter on. The shield seals to the hood to insulate the incoming air charge from under hood heat while the mass air sensor tube is designed to match the stock mass air meter signal so that no aftermarket tuning is required.

Steeda Autosports ProFlow Cold-Air Intake

PN 555-3155
HP/TQ Gain: 38/36
Tuning Required: Yes

Steeda's ProFlow cold air kit starts off with a large diameter molded induction tube in black with a fine grain finish. The mass air flow sensor housing is a high quality CNC machined billet aluminum part with a built in velocity stack where the filter attaches for a smooth airflow transition. The billet housing increases the mass air sensor tube inside diameter to 95mm. The Steeda high-flow filter uses synthetic filter media that is cleanable and requires oiling. Shielding the Steeda filter is a powder coated metal heat shield that uses a plastic bolt-on base to seal the assembly to the stock cold air snorkel while a rubber seal takes care of sealing the shield to the hood. Black hose couplers with high quality clamps finish out the package. The Steeda kit retains all factory hose connections and you can delete the sound tube, however Steeda only supplies the plug for the induction tube itself. Steeda is another manufacturer that offers a package deal with their cold air kit and a SCT hand-held tuner.

Don't get ahead of yourself in the installation like we did and install the stock mass air sensor into the CNC tube before the tube is passed through the filter shield. The CNC tube will not clear with the sensor installed.

While Steeda makes their heat shield out of metal, this nifty “scoop” bolts to the bottom of the shield to allow the sealed off filter area to get the coolest air possible by reusing the cold air snorkel. Matter of fact, the Steeda part doesn't just butt up to it, but slips inside the snorkel's rubber seal.

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Pushing Electrons

As you've read through our guide, you've seen some entries that state tuning is mandatory and their instruction manuals even state to not drive the car without the proper tune, as a lean condition can result. You've probably noticed that the cold air kits that require a supporting custom tune also show higher horsepower and torque ratings. That's due to the performance improvements further enhanced by the tuner itself with timing and fuel changes. Even the no tune needed kits will benefit with the adoption of an aftermarket performance tune, it's just that they don't have to have one to be installed. Generally you'll see a 10-15 hp improvement with a cold air kit, while the remainder comes from the aftermarket tuning.

One of the most popular tuning products is the SCT hand-held tuner, shown here. The majority of the cold air manufacturers have worked with SCT to devise custom tunes so that you can actually buy your cold air kit and SCT tuner as a package deal (even Ford Racing does this on their '05-'09 cold air kits). You can also order a SCT X3, which has no pre-loaded tunes, and then have a custom shop dyno your car and create a custom tune based on your Mustang's modifications. If you'd like to know more, be sure to check out for more info and your nearest dealer.