Honda's Fit-it isn't the enthusiast's performance dream car come true. But Honda fans have long taken cars perceived to have little dream value and extracted big things out of them. Of course, this almost always begins with the exhaust system, which is perhaps the most basic of all performance upgrades. Also earning a reputation for standard bolt-on fare, electrical ground strap kits have earned street cred in their own right. And while exhausts and grounding kits may not seem like they belong in the same sentence, they've both become target mods for new enthusiasts if for nothing more than their aesthetic values. The best part is that they provide honest performance gains.
Replacing the factory exhaust system is perhaps the most primitive of vehicle modifications. From high-end supercars to ghetto beaters, there is a high-performance exhaust for almost every car. But many who bolt on such systems never really understand what it is they're gaining and how those gains are obtained. To be sure, imagine that your engine is an air pump. It ingests air and fuel and exhales the used exhaust gases through the exhaust system, which includes the exhaust manifold or header, the catalytic converter, the exhaust piping, and the muffler. A free-flowing exhaust system simply allows all of this to happen more efficiently. However, Honda exhaust systems-and its vehicles for that matter-are designed for the masses, not for power-hungry enthusiasts. Quiet is better than loud; less emissions is better than more. The results often create a bottleneck, which impedes proper airflow. As a result, a high-flow exhaust system such as HKS' Hi-Power Fit exhaust doesn't just sound better, it actually makes a bit more power.
Electrical grounding kits like HKS' Circle Earth kit are a bit of a mystery, but they needn't be. Simply imagine your car's grounding system, and then improve upon it by adding several more grounding points. The results decrease electrical noise and can even smooth out an older car's idle and produce more power through a stronger spark.
Installing HKS' muffler onto the '09 Fit is easy-it is, after all, a muffler and not a cat-back system. With the stock exhaust removed, the HKS Hi-Power unit is fitted into place using the original hardware. But the Circle Earth grounding kit requires a bit more work. First, you must take into account the vehicle's components that potentially create the most electrical noise-like the distributor found on older Hondas or the alternator. But newer Hondas like the Fit feature a direct-fire ignition system instead of a distributor, which alleviates most of that noise to begin with. Ground straps can be distributed from the main unit to the valve cover, the alternator, and the body. Arbitrary points like the transmission body, cylinder head, fuel rail, and intake manifold are also good locations. HKS' kit includes plenty of wire, so be sure to leave enough slack for engine and drivetrain movement
For testing, we sent the Fit off to JDM Concepts in nearby Oceanside, California, where it was strapped to the Dynojet. Baseline runs using the OEM exhaust system were made and subsequent runs testing the exhaust and grounding system were made in 30-minute intervals to allow adequate time for cooling and to avoid heat-soaking.
HKS's Hi-Power exhaust system increased power by 2 hp throughout the powerband, and although the Circle Earth kit increased power slightly, actual gains are minimal on such newer vehicles. While 2 hp may not sound like much, keep in mind that such parts are prerequisites to the big picture. Pairing the Hi-Power exhaust and Circle Earth grounding kit with an intake system or an ECU re-flash will only realize larger gains and help contribute to the total tuning solution.