It looks like the race series we compete in (1.8T Audi TT) may require restrictors on turbo cars from next year, so I've got some learning to do

I appreciate the turbo and engine behaviour will be very different, and the turbo spec is likely to need changing to work properly, but am trying to find some accurate technical articles to learn more.

We don't know yet what size restrictor etc, or indeed if it will happen, but some reading up won't harm

Any suggestions welcome. (apart from "take it to the professionals and pay them lots of money to get it right", as that's not the way we work )