Our friends over at Kooks Custom Headers are at it again. The 2011-current 5.0L powerplant found in the Mustang has been setting the industry on fire with its performance and power, and after careful examination of the marketplace, the team at Kooks decided that building a true, big-tube header to connect to the factory exhaust was the next step for their product line. Why are these important, you ask? Because as we move forward, it’s expected that Big Brother will continue to exert its influence upon the automotive aftermarket, clamping down on the performance parts that can be manufactured and sold to the buying public in the interest of emissions control.


True big-tube header performance in a small package - these are designed for the weekend warrior who doesn’t want to deal with emissions concerns.

The Super Street Series are a huge improvement over the stock pipes, with large 1 7/8-inch primaries and 3-inch collectors, with 3/8″ flanges for sealing superiority. In addition, the headers are constructed from 304 stainless steel, which provides rust resistance throughout the life of the product. These are designed to be a direct-fit replacement for the factory manifolds, bolt right up to the factory cat pipe, and will provide a proven 10-12 horsepower and corresponding torque gain throughout the powerband. No cutting or welding is required for installation - they bolt right in.

JDM Engineering just tested a set of these on a customer’s car and were impressed with the fit, finish, and dyno performance. JDM’s Jim D’Amore, Jr. explained, “With even a high flow catted mid-pipe, many of the 2011-up cars will still have a hard time passing an OBD-II emissions test even with proper tuning. Kooks now offers a cost effective way around this problem. The Super Street headers allow you to easily change your high flow mid-pipe, used for off road use, for a stock catted mid-pipe for every day street use. With proper tuning, your Mustang will not have issues when it comes to inspection time either.”


JDM Engineering tested the Kooks Super Street Headers on a 2012 Mustang GT. According to D’Amore, “Base line runs (run file 02) were done with a Steeda CAI, GT500 mufflers and JDM Tune. All other powertrain components remained stock. In run file 04, all factors remained unchanged with the addition of the Kooks Super Street Headers. On run file 05 the high flow H-pipe was added.”

Continuing D’Amore said, “Initial testing of these headers showed an increase of 10 rear wheel horsepower and 8 foot pounds of torque at peak, and an average of 14 rear wheel horsepower and 13 foot pounds of torque in the midrange. When combining the Kooks Super Street Headers with a high flow H-Pipe, JDM recorded an increase of 8 more rear wheel horsepower and 10 more foot pounds of torque at peak and even more (10-15) in the midrange power band.”

According to Kooks’ Chris Clark, “This is a new venture for Kooks that we are taking head on. We have been striving to make emissions-friendly exhaust systems for the last couple of years. It started with the introduction of our Ultra High Performance 49 State EPA Legal Green Catalytic Converters last year and is growing with the addition of our new “Super Street” series of headers.”

“The idea behind the Super Street series, is to offer a 304 Grade Stainless Steel header that is lightweight, produces horsepower and torque and will enable anyone to pass emissions,” continued Clark. “These OEM connections headers produced an average of 13 RWHP on a dyno and over 10 ft lbs of torque gain. They weigh 4 pounds less than factory manifolds and up to 8 pounds less than the competitors. They bolt directly up to stock cats, and we are finishing up our Off-Road X or H pipe that will connect to these headers.” With an expected retail price in the mid-$600 range, these are sure to be a winner.

JDM Dyno