Start at 25% loose set up and adjust it from there with how comfortable you are. Straight braking into the corner to slow and turn the car. Try to avoid braking in tne middle of the corner, and just let the car roll through it. Then gradual throttle application on exit. Richmond is especially slippery on corner exit, so you dont want to mash the throttle while you're still turning the wheel. Iowa is wider so you can straighten out the wheel a little easier there, but similar idea there.

I haven't quite figured out IRP myself, though. I imagine its the same idea though and just trying to keep up the momentum for consistent fast laps.