Will the gear stick take off? Barnz, the synchro is designed to brake the driven element to match speed. Removing the engine load reduces the requirement to brake and if the duration of the spark cut is the same/slightly longer than the time it takes for the synchro to align BEFORE the braking portion of it function occurs it's possible to shift without a clutch Not point discussing dog/straight cut gears as a dog clutch is designed to shift under load (basically has larger "windows" of alignment hence can be forced through under load) and a straight cut gear can also be using in synchronised applications the simple fact is cut spark slightly before and during and after the shift to given the synchro time to align and engage and you can shift without reducing throttle input/engine RPM and thus retaining boost on the shift. "Under Load" probably isn't the best way to describe it, also im not suggesting it will do wonder for the longevity of the box but it is doable.