Originally Posted by Cudacharger

maslin- Still running stock servo and tracks like a bullet. Exotek turnbuckles and YR steering alum upgrades fix the wandering issues.

Originally Posted by fyrstormer

Every time I have had random left/right wandering while accelerating, it was because the chassis needed a rear swaybar to make the rear suspension squat evenly when the weight transfers to the rear during acceleration. Then, of course, it needs a front swaybar too, to counteract the oversteer effect from stiffening the rear suspension. I don't know if there are swaybars available for the RS4 3 Sport; if there aren't, the only other solution would be to install stiffer springs and accept the tradeoff of a harsher ride.

On the other hand, if it's wandering while cruising at a constant speed, that suggests it needs toe-in (or less toe-out) in the front. If it's wandering when coasting or braking, that suggests it needs toe-out (or less toe-in) at the front -- also a fix for super-twitchy steering. If the wandering is actually caused by the rear stepping-out, then it's the the *rear* wheels that need more toe-in.

All of this assumes the steering moves freely when disconnected from the steering servo, and the servo itself has no detectable slop. (some cheap servos do have slop, even if they have metal gears.)