I've seen this subject on here a few times now, and I think it should have its own thread. this is basically what I get out of it. I'm using the TC line of turbonetics for example because that information is what I have in front of me. what little bit of info I could find anyways ... not to mention, the number of choices and combonations is mind boggling. LOL.

Compressor sizes offered, TC58, 61, 66, 67, etc. Turbine trim, P, F1, and Q.

the compressor is going to flow X lbs at X turbine RPM. pick your compressor side based on your overall HP goals, and thats it. This is going to be our constant. The way that the turbine gets to said RPM is where we are left. Since I cant find any hard sizes, I'll just say the P is the "fastest" spooling, flows the least, and the Q is the "slowest" spooling and flows the most, with the F1 in between. Because of the design of the turbine wheel itself (pitch, size, blade shape), the A/R isnt as big of a factor with this particular manufacturer. Basically pick your trim. That said, I would like to see more information on the hot side than the manufacturers provide (which from what i can tell is next to nothing).

So, it seems to me, one compressor design can go from kinda soft on the bottom with a strong top end, to fairly snappy on the low end and out of breath quicker, only with a hot side change, within reason of course. Both of them are pushing the same amount of air, at the same turbo rpm, but one is doing it at 2500 engine rpm, and the other is doing it at 4500 engine rpm. does this sound about right?

- This all takes into consideration that you size the compressor side according to your end goals. if you do that then it makes the rest fall into place easier. In other words, nothing is going to help you if you stick a thumper on a ecotec haha.

 

hanging out for details !