2010 Honda CR-Z - Project CR-Z - Exhaust Flow Upgrade - Honda Tuning Magazine

Our Project CR-Z build has touched on a little of everything, including aero, braking, interior, custom fabrication and (very slight) power improvements. With just a few months left before our loaner goes back, we stumbled across one of the most simple and effective naturally aspirated power upgrades one could possibly imagine for the little 1.5L. Power Rev Racing, or P2R as it’s known, has developed a section of piping that essentially frees up a bottleneck in the factory exhaust system. As most already know, the main catalytic converter sits just inches away from the exhaust side of the engine’s head, tied directly into the exhaust manifold. However, a second catalytic device is also used further down the exhaust path. Removing this portion of piping you’ll quickly see why it’s such a restriction. The accompanying photos show just how puny the piping actually is, and that’s where the P2R “downpipe” comes in.

Utilizing larger-diameter piping and a smoother exhaust path, the aftermarket piece opens up the factory restriction, and the result is more usable power and torque. Keep in mind that the main cat is still in place, and you won’t be blowing plumes of pollution through your local neighborhood, nor will you have to yell to your passenger due to excessive noise levels. Although the exhaust tone was sharper and overall a bit louder with the new piping, it isn’t overpowering or annoying. As we pulled into the office parking lot, our cigarette-sucking coworkers weren’t aware any changes had been made as we drove through rows of cars looking for a parking spot. Additionally, you CR-Z owners won’t have to worry about the infamous check engine light, as P2R has included a bung for the factory O2 sensor. No lengthening or modification is necessary; it screws right in and you’re good to go.

On the road, the difference is noticeable from the moment you begin to accelerate, even in “Normal mode.” Transitioning onto the freeway is much better (aka safer) with the additional midrange torque, and the CR-Z finally feels like it can get out of its own way during homeward-bound traffic sprints. In “Sport mode” the car’s immediate torque curve on the bottom end is noticeably enhanced, and there’s absolutely no doubt the upgrade is effective, with dyno results to confirm this. Those who have spent any time with the CR-Z are well aware that after the “assist” falls off in the midrange, the car falls completely flat. However, with the new downpipe there’s now a solid feel in that 3,500–5,000 range that was basically a wasteland previously. Installation requires only basic hand tools, but we’d highly recommend using a lift to make your life much easier. We were lucky enough to score a few hours of time on the lift at Raceline Development, and Elton Lo even grabbed a wrench to give us a hand. With the car still very new, we probably could have used the factory flange but contacted Vibrant Performance for a replacement just in case. As usual, Vibrant had our part in stock and ready to ship immediately. The company carries factory replacement and aftermarket and performance products for anything you can possibly imagine.