If you have a huge turbo and a massive intercooler so that you have a good enough supply of the correct temperature of boost (ie as cold as possible) then you can keep upping the amount of power it can handle by retarding the timing more and more, but it will be horribly ineffiecent (due to the timing) and very laggy (due to the huge turbo)

Seems like a stupid way to spend your money when you can just fit some decent rod and pistons for not much more than a grand anyway.