I'm running a sequential FAST box but don't have a cam synch, so it's not running in seq mode. It idles smoother and more consistent than the carb did as is. I'm running 37# injectors on a 383, ran for 2yrs NA and with the oversized (for NA, almost done with the turbo install now) injectors never caused any trouble at idle. Seq is definitely not a necessity in my experience.