What is IMRC?
What is intake manifold runner control?
A lot of the info here is general modern mechanics, but some of it, including pictures, points more specifically to the Audi C5 platform S6, because this thread is a side note to the “C5 S6 V8 power build” thread in the A6/S6 section of this forum. Since this is an often misunderstood or unknown topic, I hope this thread will one day show up on Google when searching for “what is imrc?”. I’m gonna break it down for everyone - the DIY guy, the service tech who hasn’t seen it in a long time, and the guy who doesn’t know much about cars at all. I hope there’s lotsa useful info here for you, regardless of whether you drive an Audi or something else.