Raceseng Revo Idlers-FRS/86/BRZ

We've meticulously refined how our parts are anodized to insure the best UV resistance against color fade while maintaining all its anti-corrosive and tarnishing properties. The brilliance of our black and clear finishes can be seen and will be easy to maintain. Our "R" is post machined, not laser engraved or pad printed, machined because its what we do best.

The harmonic balancer has the sole responsibility to retard or lessen the resonant frequencies that occur during the normal operation of any internal combustion motor. The crank is like a tuning fork for musicians; when the firing cycle hits each cylinder, its like a flick to the tuning fork. So when you see the term "harmonic", it is a literal description of what is occurring to your crank. Your crank is actually flexible, believe it or not, if it wasn't, your engine wouldn't last more then 10,000 miles. It flexes on a microscopic level to absorb the explosion from each cylinder, this flex is precisely what creates an engine's natural frequency. Some vehicle's frequencies are more violent then others due to the architectural layout of the cylinders. For example, a V6 or V8 will have higher resonance because the downward thrust of each cylinder travels through the center-line of the crank in a non-linear pattern; this actually has the ability to amplify the frequency, depending on your RPM. Compare this to an I6 or I4 and you reduce the harmonics due to the linear pulse of the cylinders approach the crank from a single direction. Finally the Flat-4, with force traveling through the crank to opposing cylinders, the frequency is reduced by its own operation. We're not saying that the frequency is completely eliminated! We're saying that of all the engine formats available, a flat-4 is the best candidate for a lightened crank pulley.