The 13.5 is just ABOUT the same speed as the Titan 12T motor, just with a tad more punch. The 13.5 is what we are using at our local, it keeps things pretty even with the box stock guys too. If you want something a bit faster I would go with a 10.5. Just keep in mind that the EZrun motors that are higher than 8.5 all have a 380 sized rotor and will get burnt up in a Slash. That's why I went with the 8.5T, because it has a 540 sized rotor. Now if you want to use the EZrun ESC and another motor like a Tekin Redline, or a Trinity Duo (these are motors that work both sensored and sensorless) then you can use any motor they make up to a 5.5t (EZruns Spec limit per the manual)

Jay