Graves Motorsports Yamaha R6 WORKS Velocity Stacks. This kit works on all 2008-2020 models (with stock, FTEcu tuning or Yamaha Kit ECU). Electronically developed and tested at the track on the Graves team race bikes these stacks smooth power and increase horsepower across the entire power band of your R6 specifically effective in the mid-range. Designed for the elite rider seeking top of the line performance, fit, finish and value. This part was developed using the same technology that has powered the Graves Racing Team to 30 Professional AMA National Championships including 9 Superbike Championship titles and 3 Side x Side Pro Titles (Pro Stock and Pro Mod UTV).