Let me see if I read this correctly... using my D15B7 at 1493 mL displacement I came up with this:

6500 RPM = 0.12 m^3/sec
3000 RPM = 0.05 m^3/sec

The 15G chart uses m^3/sec so I converted my lb/min results to that so I can graph it, using a 162.04 conversion factor.

I concluded that at 12 PSI @ 6500 RPM that I am toards the top (at the 1.8 pressure ratio line) of the middle efficiency island of peak efficiency. At 3000 RPM I am just entering the right side of the chart, at 0.05 m^3/sec.

Is this a correct reading?

I re-did calculations at 15 PSI at 7000 rpm and concluded that I am towards the edge of the 75% island still. Would this mean that 15 PSI should be a fairly good setting for the Greddy 15G kit? I had always heard that it doesn't do much over 12 PSI... but this doesn't seem to be the case.

Even 20 PSI is still in the 73% island at 7000 rpm, towards the top right edge, although it looks like turbine RPM is getting very fast but I'm still well within the chart. Is there anything else telling me to stop there with the 15G?