A lot of the games are currently getting throttle mapping to RPM wrong. In Assetto Corsa if you put 20% into the throttle in neutral the RPMs will climb to red line and the throttle position just determines how quickly that happens and its because they aren't doing this correctly.
Is this not more so a modern<->old car neutral ethrottle thing? I haven't driven a cable operated throttle car but on bikes 20% will probably hit limiter.
I'm gonna try it after work.
The only precision revving in neutral I've done is for emissions testing a couple times but the throttle tube was barely rotating to keep it at 4k. It was still at that point where the cable just gets tensioned past the freeplay and it was kinda tricky to keep it there since very small movements would move 0,5-1k RPM.
PS: Treating 20% as 20% throttle tube rotation, not necessarily linear to how much chooch you get due to how throttle bodies open.
As a side note, BeamNG.Drive has the most accurate throttle response and audio response of any driving game I've ever tried. You can almost feel the car pull vacuum (or build boost).
You also need to simulate load on the engine even in neutral. With no load, the speed genuinely would rise to red line at a rate controlled by throttle position.
