Alot will depend on compression and timing too. In my turbo buick 15-16 on 93 and with race gas I've seen people put 24-26. Granted thats for a motor built for boost and a tune thats low on timing. Also, depending on the car you might want to add timing with the race gas. Some cars will like more timing than more boost.
I really don't know enough about alky to even consider switching and trying to tune it at this point, other than I'd have to dump a lot more fuel in it which means bigger injectors. And bigger injectors means switching to a low impedence driver and I'm not really wanting to go that route yet.