Out of complete and honest curiosity, would it be physical/mathematically possible to have a tri-turbo set up? Like a smaller one that spools from 3-5k medium starts at 4.5k-6.5k and large 6k-9k
The compound setup like it tractor pulling uses the big turbo into the smaller turbo (It could be the other way around) to super compress the air. Like I said it may be the other way around.