I don't know how valuable this info will ultimately be. As Goran stated, there are too many variables that are not listed.
A buddy of mine recently went through an extremely thorough tuning of his 930 engine which ran well at the time. Being a perfectionist he knew there was more. In the end he picked up ~40HP and dropped his lag 600RPM - all by tuning the ignition and fuel.
RarlyL8 Motorsports / M&K Exhaust - 911/930 Exhaust Systems, Turbos, TiAL, CIS Mods/Rebuilds
'78 911SC Widebody, 930 engine, 915 Tranny, K27, SC Cams, RL8 Headers & GT3 Muffler. 350whp @ 0.75bar
Brian B. (256)536-9977 Service@MKExhaust Brian@RarlyL8