My opinion on the 9volt mods from watching them on YouTube is they are too fast for the tracks and this is why I never tried one. If you are looking for additional speed with little modification I would recommend replacing the motor unit with a Tamiya Power Dash or the like. Simple and easy.
![[Image: 7071.gif]](https://www.allsmileys.com/files/sweetim-texticons/7071.gif)