Quickshifters do not generally retard the ignition on upshifting they cut it for approx 50-60 milli seconds, if you want clutchless downshifts as well as upshifts without a slipper clutch take a look at .: Flat Shifter - Performance Gear Shifting & Automotive Products :.
graz
clutchless up shifting
Hi,
i use a bit of kit called a Flatshifter on my bike it enable`s full throttle or partial throttle clutchless up gearshifts and clutchless down shifts works as smooth as silk i got it from FlatShifter Performance Gear-Shifting and Automotive Products...