DLL is best for tuning, as y8s has pointed out. Used correctly, it's consisent. The absolute numbers are going to be a little different and I can certainly understand how the shape of the curve might change compared to a chassis dyno. Look at it as a tuning tool and it's a good one.

hey thanks for reminding me. i took a quick screen cap of a log done on a dyno to compare to the dyno(jet)'s output. I spent 30 seconds getting the peak power to the same value*.

DLL:
http://y8spec.com/dyno/20070512_DLL.gif

Dynojet:
http://y8spec.com/dyno/dyno20070512_8-10psi.jpg

*Just noticed a MINOR error though. I used the 8psi DLL graph at the 10 psi power level. You can mentally correct for that.

PS never listen to the muscle car guys fuel tuning advice. I did that for run 4 after increasing boost ~2psi.

PPS the difference between run 1 and 2 is letting the hydra autotune. note the fuel curves!

PPPS here is the screen cap of the data portion of the datalog:

http://y8spec.com/dyno/070512_dyno003_log.gif

Matt