Graves began development on the ADSD™ system due to increasingly strict sound regulations for competition world-wide. The goal was to exceed the exceptional level of quality and performance of previous generations of Graves Motorsports exhaust systems while complying with all regulatory bodies in regards to decibel levels.
The average ADSD™ sound reduction over a conventional-style exhaust is 2.5db, while maintaining horsepower increases of 12-20%. The secret is in the two-chambered header pipe, specifically tuned to divert returning exhaust pulses, avoiding power-robbing turbulence near the exhaust port and reducing sonic amplification.
This system has been extensively tested by the Graves Factory Supermoto Team and was used by Brandon Currie to sweep the 2008 AMA Supermoto Lites Championship and on Mark Burkhart’s 2008 Moto X Games race winning machine.
2007 - 2009 Yamaha YZ450F 98 DB @ 4000 RPM
2008 - 2009 Yamaha YZ250F 98 DB @ 5000 RPM
2008 - 2009 Yamaha WR250R 95 DB @ 5000 RPM
2008 - 2009 Yamaha WR250X 95 DB @ 5000 RPM
MSRP around $800