After being convinced that the turbo on my mini is too big, I have a question: is 10 psi from a T3/T4 .57 trim the same as 10 psi from a Garrett TII turbo? I mean, is the same amount of cfm getting into the chamber?
I understand (now, anyways) that the .57 trim is not the best turbo for an 8-valve. But what I can't understand is why at 15 psi with a Mitsu turbo (stock) the mini pulled pretty well, but with this .57 trim at 15 psi it feels like an n/a. It seems to me like the cfm would have to be the same in that both compressors are feeding enough air to creat 15 psi of back pressure. Is this right?
What am I missing? Keep in mind that I am not a turbo guru, which is why I am asking. I am reading "Maximum Boost" for the third time and get a little bit more each time I read, so don't flame me. I just need to know why! This turbo came off of my Miata, and it dyno's 263 rwhp at 19 psi. Granted, it took a while to spool, but when it did it pulled like a madman. I took it off of the Miata with about 5000 miles on it, and I put it on the van. But this van ain't pullin' at all (well, very slightly).
How are the boost levels different? Thanks!

-Les