Originally Posted by FD Pilot
Well, KM seams to know more about this than I do. I set mine up like the pre-production Vyper Scott Stoops flew at AEF Jan 2009. As I recall the recommended setup for the Vyper when it first came out was the Torque 2814/820 or Omega 130/870 with 4S and the Torque 2818/900 or Omega 103/1030 with 3S. Since I was replacing my Aspera with the Vyper I went 4S with a Torque 2814/820. I've since switched to an Omega 130 to save a few grams an move the CG back. Now it seems the tide has changed and 3S is preferred according to KM. Just remember with 3S you will need a 55 amp speed control and more current capable batteries. A 45 amp ESC, which is perfect for a 4S setup, will not be big enough.
speed and weight... 4S has excess, that's all. You can drag it all back to samey-samey with smaller packs and smaller props, but in the situation of the original poster is that they already have 3S 2200 packs. 3S being more than enough, makes the recommendation a no-brainer.