Quick question regarding engine pulsing.

[Søren Holm Pedersen]

Hey!

So I have a question!

So I saw a video a year or so back of an amateur enthusiasts car in which said enthusiast had installed a sort of engine pulsing system. It would be idling but every 0.5~-1~ second it would rev up something around 100 to 300 rpms but always returning to idle before getting revved again. This is an automated system he turned on with a switch.

The same system is heard in the Mazda 767b, albeit somewhat faster than per-second intervals of the revs, as per demonstrated in this video:

.

So my question is as follows: What is this system or function called in motorsports terms? I'm really keen to finding out but I can't for the life of me find the video which said what this was, nor can I find anything by googling something in the lines of "race engine surge" or "race engine pulse"

Any ideas?

Thanks,
Soeren