Originally Posted by Dave H

Not sure on the on road thing, imagine a touring car could load up the steering quite a bit due to high traction and cornering speeds, and 4wd, but I’m just speculating, don’t know.

I don't have a short course, but imagine 2wd SC would be fairly similar to a stadium truck, suggest looking for at least 140 oz-in or so, would expect 200 or so to be plenty. Little advantage in having way more torque, but it probably won’t hurt anything.

For speed I would suggest 0.10s or quicker for both of your cars. Some will disagree, concerned about making the car darty, but for me more speed has always been helpful. With one caveat, this can get complicated to explain, but some servos have very hot feedback tuning in an effort to improve performance with a given motor, and are twitchy & noisy just sitting, they tend to overshoot slightly under a quick input. I don’t care for that, prefer a smooth response without overshooting.

Good questions, in my opinion a good quality fast steering servo with enough torque is the single best and most important hop up there is. A fast car isn’t much good if you can’t control it.