DYNO PORT TORQUE: Don’t let the design fool you! The Dyno Port Torque pipe barks up top. On the stock YZ, the DP pipe felt much like the FMF/SX silencer combination, but with a better midrange hit. On the piston-equipped bike, the DP exhaust produced a hard-hitting powerband similar to the FMF/SX combo, but with a tad more on top. Definitely a solid performer.
DYNO PORT MID-TOP: This was without a doubt the most specialized pipe of the bunch. Low-end power was seriously enhanced on both machines. Midrange was about the same as stock and–as advertised, top end was off the charts. Perhaps on wide open, sandy tracks, the Mid-Top pipe would be favorable, but we have no such tracks in our Southern California testing locale.