Cost. A single turbo like the ones I have picked out would have perfect response for the rpm range I’ll be in the entire time on track. A 2.6-2.7L spooling a twin scroll 35R or 40R would be perfectly fine. I’ve been doing research, trust me. Another thing is due to the decreased traction I have, I’d rather have a little lag so the car can get up to speed before blowing any sort of rubber off. The twin setup would just light them up.