Has anyone attempted to run a parallel twin turbo setup where one was a smaller, lighter turbo (say a 16g for spool-up purposes), and the other like a GT35r (more flow, obviously)?

 

That's called a sequential setup. This is more complex than a parallel or a compound setup as you have to have multiple valves in the piping to switch one to the other or to run both. I believe this was tried on the Supra and maybe a few others, but most of the Supra guys switch to a large single. It may have been two of the same size turbos or two different size turbos on the Supra; I don't remember, but the concept is similar.

In theory it sounds appealing, but I have never really heard of one that performed "so much better" than a simpler setup. But that's just me; maybe someone else has.

 

in the end what are you really trying to accomplish? bad *** daily driver? just get a smaller turbo and big cams to help along the top end. if you're going for racing... a single turbo is lighter as an assembly and would be preferable czu there's less stuff to break.