What transit speed of a servo is fast enough? Will be using it in a 4wd short course truck. Is .10 pleanty fast enough? whats too slow. And what spped should I use in a 4wd tenth scale buggy?

This doesn't apply to you but for throttle servos, faster is better. Give me all the speed they can make.

For steering servos, you need some speed but it doesn't need to be ridiculous. I would say .15 would be a good number for the slowest I would go. .12-.10 is plenty fast.

transit speed is more important for steering in an onroad car. the faster the better, gives a much more precise feel. offroad a bit slower is fine, offroad trucks dont react the same, and too fast can make them twitchy. .10-.12, as stated, is just fine. just make sure you get something with some torque to get those tires turned.

I run 10 and 12 and that's plenty fast!!!

I have .08 and it was a bit too fast, had to turn down steering sensitivity

Great the one I bought is probably way too fast .06, oh well like Dave S said I can turn down the Dual Rates. Is 306oz. of torque enough for 2wd short course truck? I found a Savox that I'm probably gonna get for my 4wd SC truck that's .10 speed with 555oz. of torque lol crazy. 150.00 bucks.

Thats all way overkill. 120oz in 2wd is more than plenty. I run a 200oz servo in a 1/8 truggy, so 555oz is crazy alright. Save some money and just buy what you need or a little above.

Yeah, my 4wd is pretty dang heavy and servo has 347.2 oz/in and it seems like overkill, I couldn't imagine 555

That's like 1/5th scale torque. I've yet to find anything on a 1/8th or smaller rc car that can't be done with 120oz/in.

I have .13 speed with 416 torque in my 1/8 buggy. Probably don't need all that torque but it should help make the servo that much more durable.

monster trucks need a lot more torque with todays wheel tire sizes. ive run 140oz/in in my savage, it takes the width of a 2 lane road to turn around.

I hope you have an esc with one hell of a bec.

I only have a little knowledge of a Savage so I could be wrong but I can't believe 140 oz isn't enough to turn the thing. There has got to be some other problem like a servo saver with too weak a spring (most likely) or bad linkage geometry or something. Either that or that 140 oz servo is really only putting out 80.

Or if you are using a 4 AA receiver pack, ditch it for something with more oomph.

in general go for the best you can afford. (that meets your needs) and look for a good balance for torque and speed

in smaller vehicles speed over torque
in larger ones torque over speed

A Savox with that much torque, I think BEC is out the window completely. Time for a receiver back.