APPLICATION: All current MX bikes
PRICE: $229.99 to $249.99 Let’s face it: modern-day motocross bikes are awesome right off the showroom floor. That said, it’s pretty rare to find an aftermarket product that provides noticeable gains across the board, no matter what the make or model. However, we were stunned by the FMF SST pipe when we first bolted one on our ’01 Honda CR125R test bike, and equally impressed when we installed one on our CR250R a few weeks later. Since then, we’ve tried out SST pipes on every one of our ’01 test bikes and¿with the exception of the Suzuki RM250 model¿have found that the FMF SST pipe is one of the best dollar-for-dollar modifications you can make to any MX bike, period. [IMAGE 1]Externally, the SST pipe looks just like the rest of the FMF pipe lineup, with the exception of the bulge in the stinger portion of the pipe. Is the stinger bulge the magic maker? Curious, we got Don Emler on the phone, and this is what we learned…
The SST System (which consists of an SST Pipe and SST silencer) was developed by the team of engineer Dave Simon, a pioneer inventor in sonic-wave technology. Simon’s history is broad, as he holds patents in the medical field, watercraft and motorcycle industry, plus holds the deeds for carburetion and fuel injection systems for both cars and motorcycles. Simon has built some of the fastest personal watercraft on the planet, injection systems for Formula One cars, and runs a movie company in his spare time.
A little over two years ago, Simon walked into FMF’s SoCal offices claiming that he had an idea for an exhaust pipe that would perform like no other before it. Simply put, the secret to SST is the patented shape of the exhaust system and its ability to increase horsepower by using the energy that flows through it.
As we suspected, Emler confirmed that the most noticeable element of an SST pipe is its various bulges and funnel shapes, such as where the rear chamber meets the stinger section. There are also differences in pipe diameters and silencer junctions, angles of the SST module, length and size of the rear pipe stamp and, of course, the silencer (both length and internal core size).
In layman’s terms, the SST exhaust system alters the sonic waves, back pressures and exhaust gas temperatures that effect engine performance and throttle response. The SST System creates a fast-moving, high-pressure “return wave” inside the exhaust, forcing packets of unburned, ready-to-go air/fuel mixture back into the cylinder on each piston stroke. By recycling and returning this potent ball of fuel in the cylinder, a bigger, more powerful explosion is created that increases horsepower and torque. The SST System also cools the exhaust gases quicker, allowing them to move at a higher rate and exit the pipe quicker, while also helping to eliminate high rpm exhaust gas clogging and unwanted “back pressure” that can limit rpm. The SST system also lowers cylinder temperatures, enabling the engine to run cooler, stronger and more consistently. The cooler operating temperatures also open up a whole new range of tuning possibilities.
Though we’ve tested plenty of traditional exhaust pipes that offer excellent performance, it is the SST lineup that¿on average¿is the most impressive.RATING: 9Call 310/631-4363, or visit www.fmfracing.com