I would go to impaktrc.com and pick up one of those tekno-neu motors they have on sale right now.. you really have a few choices;
- 1515 1.5d is great on 4s (up to 50mph) but is capable of running 5s or 6s for pure insanity (this motor gets you fastest speeds but least amount of run time of the 4)
- 1515 1y is a nice racer on 4s, but can be slow for some bashers, drop in 5s or 6s lipo and again true insanity.. expect up to 40 on 4s, 50 5s, 60 6s (about 10mph less than the 1.5d) This motor will run a little cooler than the 1.5d and have slightly longer run times depending on your gearing.
- 1515 2d is a sweet race motor on 4s or 5s, this will be more like 35mph on 4s, 45 5s, 55 6s. This motor will run cooler yet and have the longer run times; you can over gear this motor a bit but at a cost of run time and temp.
- 1515 2.5d is a touch faster than stock (tons more torque) on 4s, w/ 4s 8000mah packs it will run a REALLY long time (~32mph), nice racer on 5s (~38-40) and getting a bit giggly on 6s unless geared down. This will run the coolest of all and have the longest run times of the bunch.
The 4s 8000mAH setup will get you the longest run time of any voltage unless you buy some really big (heavy and $$$) packs. A 6s 5500mAH setup would run longer, but a 6s 5000mah will
not - a 5s config would need 6500mAH or bigger packs to net a longer run time. That all said the tekno-neu 2.5d on 4s 8000mah packs will get you the speed you want with the longest possible run times & the MMM v3 is a great choice..