Ask ten riders the first aftermarket purchase they made for their bikes and chances are nine of them will give the same answer: an exhaust system. It's hard to resist the howling whine of an engine at full song, and letting an engine exhale easier not only releases more of that wonderful exhaust note, but it can also free up some power in the process. The problem has always been that with the altered air/fuel ratio brought on by the new exhaust, reconfiguring of the fuel injection (or re-jetting of the carburetors for those with older bikes) to achieve a proper mixture has typically been required.
FMF doesn't think that needs to be the case. Its Apex line of slip-on exhausts is completely designed and manufactured in its Southern California headquarters to operate without any recalibrating of the motorcycle's stock fuel system. While relatively new to the street side of the market, FMF has been heavily involved in off-road competition with both two and four-stroke machines for over 30 years. The company isn't dipping its toes in the street scene though-they're hitting the ground running. In the AMA, the Corona Honda American Superbike team is supplied FMF exhausts, and FMF's other street offerings are pretty vast.
Curious as to the performance benefits of the Apex without a fuel-injection recalibration, we decided to test the Apex on our Kawasaki ZX-10R. The exhausts are available in two versions - a carbon fiber canister with titanium tip, or a titanium canister with carbon tip. A titanium mid-pipe comes with each kit. We received the carbon canisters for the Kawi. Installation was pretty straightforward as directions and all the required hardware is already included. Also included is a cone insert to quiet down the exhaust note and keep the neighbors happy.
First thing we noticed was the improved mid-range power. Of course, this was all according to our butt dyno. So a trip to our official Dynojet dyno was in order. Stock, our ZX-10R put out 161.7 horsepower and 75.6 ft.-lbs of torque. With the unrestricted Apex slip-on those numbers jumped to 164.0 horsepower and 76.5 ft.-lbs. Conversely, with the cone in the quietest (most restrictive) setting, both numbers dropped slightly to 161.2 and 74.8, respectively. Yes, less horsepower and torque than the standard setup.
While those numbers are significant, what's more significant are the dyno curves, as the application of said power is much smoother than before. Stock, the ZX-10R would have dead spots when getting on the gas-usually between 4500 and 5000rpm-a result of trying to make mother nature happy. Now the flat spot is gone, replaced with smooth and linear power delivery throughout the rev range. What's more, the Apex drops a hefty chunk of weight by ditching the stock cans; the Kawasaki dropping nine pounds, to be exact.
Though they may be new to the game, FMF definitely has brought its expertise from the dirt side to the street with the Apex series of exhausts. In all of our runs the power outputs have smoothed out considerably, making for linear delivery of power where you use it most. The Apex you see here retails for $549.99, though pricing varies for underseat and dual-exhaust setups.