ok I did some looking and can't find a thread on this anywhere. I got any from R/C and now they have high voltage servos. What are they for? In what application are they required.

HV servos have higher torque numbers than a normal servo that runs on 6v. Mostly used in 1/8th scale.

So they just have higher torque and/or faster speed? I heard something about burning out non HV servos on Lipo. What difference does that make?

7.4 lipo receiver packs deliver more voltage than a non HV servo can handle. IIRC, if you run standard servos with a lipo receiver pack you need to use a regulator, HV servos can handle the full voltage of the lipo and don't need a regulator, which is why HV servos are rated at 7.4v not 6v like a standard servo.

Ok that makes sence. I suppose that either the esc or the reciever in an all electric setup steps down the power going to the servo then?

exactly, the esc steps down the voltage to 6v. Can't say for sure what guys are doing with 1/8th electric setups to get 7.4v to the servo, some esc's have and adjustable BEC I would guess, or they use an external one.

BEC~ battery eliminator circuit

what application are you looking at using HV servos for?

Just didn't have them when I was racing before so I wanted to know about them. Thanks for the info.