[wetpee]

Short stroking will give a little bump in cycle time as well as lessen the risk of premature engagement of piston and sector gear. In my 12:1 build, I SSd 3 teeth and used a guarder SP110 which put me right at 1.1j (350 FPS on .2g) If you go this route, the safe way is to only remove teeth from the pickup side of the gear to maintain timing of piston release with nozzle extension. If you want to nitpick about efficiency, however, you could probably remove one tooth from the release side and be fine. The gear is balanced to account for those teeth being there so removing a tooth from the release side helps it stay closer to being balanced which will minimize wobbling. In either case, proper shimming will keep the gears from wobbling excessively. This method of SS might require shortening your tappet spring to help the nozzle make it all the way forward before the piston releases. Common practice for DSG building.

 

[wetpee]

Overspin in semi is also a concern on weaker springs with high discharge batteries without a torque motor or AB mosfet. I would opt to stay away from AB as much as possible but it may end up being a requirement if you're not keen on custom modification of your parts. Short stroking will also help mitigate overspin. The Maple Armouries RIFs are running 13:1 gears on a ZCI High Torque motor (22TPA) without an AB mosfet out of the box. Not sure if they are short stroked or what spring is in it, but mine shoots around 370 on a .2g with zero issues on an 11.1V LiPo. I'm sure the spring is at least a 110.