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By Darr Hawthorne
Photos by Zak Hawthorne
8/8/05 |
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and get rid of some of the clunky ducting from the factory. We installed the K&N 69 Series Typhoon Intake on a 2004 Subaru WRX Impreza. The advertised improvement said the system would add up to 15 horsepower. The car came equipped with a turbo so improving the airflow should help it breathe.
 To make a real world test we headed to SoCal’s California Dragway in Fontana where coincidentally K&N was holding a Sportsman Tune-up for the Super categories. After going through tech we headed toward the staging lanes and onto the freshly prepped quarter mile. After three passes the best ET and MPH on the stock factory delivered set-up was 15.129 at 89.80 MPH.
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With minimal tools in hand we laid-out the instructions and replacement parts to add the K&N fresh air intake replacing the factory stuff. Removing the factory pieces was well documented in the printed instruction included with the new intake.
While still at the dragstrip, in just 40 minutes the K&N unit was installed and was working so we headed back to the starting line, but after two passes we found that the Subaru had actually slowed down almost two tenths.
On Monday morning I was on the phone with one of the sport compact techs at K&N to explain our dilemma. Something we’d missed, according to the helpful K&N advisor, was that the car’s computer needed to reconfigure the new improved airflow. He suggested we drive the car for 50 to 100 miles and then take it back to the strip to check the car’s performance.
 Since Southern California had one of the wettest winters on record and rain hampered action virtually every weekend on the dragstrip, almost 600 miles had accumulated before we could get back down a quarter mile. Upon returning to California Dragway on a similar overcast day with a comparable temperature, first we checked all the mountings, screws and brackets and everything was as installed. When we made it back the quarter mile, the elapsed times had improved by almost .008 and increased about two miles per hour.
 With the addition of the K&N Typhoon Intake you’ll probably feel better throttle response as we did, but you’ll also hear the turbo spool-up since the factory ducting and sound deadening is removed to clear the air path. That’s not a bad thing for a real gear head motor enthusiast. We’d already improved the exhaust with a factory STI hi-flow muffler prior to installing the K&N unit, but to really feel the potential of this new system it was suggested that we reprogram the onboard computer. Retaining the existing Subaru warranty prevented us from going any further. Still, we were able to go quicker and faster and retain the warranty, with just a bolt-on addition and that's a good thing.
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