i got a turbo from someone, and it's supposed to be a t3/t04e .57 a/r. thay being said, it's a homemade turbo and has no marks on it anywhere that say what the trim or a/r are. how can i tell if it really is what the guy say's??

 

a homemade turbo?? thats new to me.....

 

i've no idea where the parts were bought to put the turbo together, but that's what I'm guessing. There are absolutely no markings on the turbo anywhere. So, is it possible to figure a/r from the outside dimensions? I know a/r is area/radius, but is that of the compressor inlet, the inside of the turbo housing, or what. Trim is based on what size wheel is in it, correct? So I'd have to take it apart to figure that out.