Well i was more talking about maximum turbo flow. Like a smaller a/r would make the turbo spool faster to produce equivalent boost. But the trim would tell you what is the max min responses of the turbo. Like look at the tubonetics compressor maps.
Look at t3 "60"
at 1.3 pr (4psi) it will flow an efficient max of 17lbs/min = 246CFM = 6850 RPM <= waaay after you will ever shift
now look at t3 "40"
at 1.3pr it will only flow an efficient max of 10lbs/min = 145CFM = 4040 RPM <= after that it will be blowing too hot of air and would be practically worthless....
that's what i was talking more about... that should be correct... or i'm not getting the turbo talk at all <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'>