Cam help

I was at a car show, and this guy was letting this car idle and it was idling smooth, and then he reached inside and said, I have a cam that I can switch profiles with a switch and he flicked the switch and all of a sudden the car it sounded like it had a big monstrous cam in it. And then he lifted the hood, and he had a little electric motor and he had a little string that was jerking the throttle and blipping the throttle and going blip... Blip....blip....dlip...
If I would have walked up and that little motor would have been on... I wouldn't have known....