Generally Speaking http://fpsspringpistols.com/racing-trucks/Redcat-Racing-Front-Upper-Deck/Redcat-Racing-FrontRear-Outdrive-Short/Redcat-Racing-Center-Diff-Mount Redcat Racing Center Diff Mount Every nitro engine even from the same manufacturer will probably tune differently, therefore you've to find out the uniqueness of 4ch rc helicopters his/her engine. http://fpsspringpistols.com/Redcat-Racing-Rear-Bumper-1-Pc/DHK-Parts-Lower-Suspension-Arm--rear-2-Pieces/Landing-Gears-For-DJI-Phantom-2-Vision-Drone-RC-Quadcopter best Landing Gears For DJI Phantom 2 Vision Drone RC Quadcopter All the models of these cars are very easy airsoft styles to use. http://fpsspringpistols.com/electric-airsoft-rifles/GG-M300L-FPS-420-Electric-Airsoft-Rifle/Electric-Javelin-Airsoft-Works-M933-Carbine-EBB-Rifle-FPS-460-Full-Metal,-Electric-Blowback-Airsoft-Gun best Electric Javelin Airsoft Works M933 Carbine EBB Rifle FPS-460 Full Metal, Electric Blowback Airsoft Gun If the spare parts of the helicopters are not widely accessible, then you will possibly encounter rc construction a series of problems in any case you have such a problem. http://fpsspringpistols.com/rc-helicopters/Mini-Parasaurolophus-Robosaur-RC-Toy/Attack-2CH-RC-Helicopter/Nano-Hercules-Unbreakable-35CH-RC-Helicopter-LS Nano Hercules Unbreakable 3.5CH RC Helicopter LS If not you might start spring airsoft guns a trend in your community by creating a club for girls. .