This highlights Ducati's improvements to the intake system from the older chassis to the 916/748.
As a comparison, here are two different 748s 'out of the box'. Pretty close actually.
The first 748 I tested was getting the cams timed, after I adjusted that, I thought I'd install the Arrow slip-ons to see what kind of improvement they would give.
The slip-ons do enhance the power in the dip around 8000 RPM and at the top of the curve.
The next chart shows the change in performance with the fairing off, to eliminate the inlet screens as well as the inlet duct opening restriction.
The 'ram air' title is a little deceiving, as the dyno cell has only about 90 MPH air velocity. It does show that the inlet system restrictions at those points aren't the worst of the problems.
Finally, the drop-on test of the Arrow intermediate system. The red trace shows the final run with cams timed and the intermediate system. The Arrow intermediate system installed before the cam timing (green) compares favorably with the stock baseline run (blue.)
In this case there is a considerable gain with the intermediate system. The owner (John Behr) has commented about the distinct loss of low-end power. I'm still working with the fuel injection map to see if that is the cause.
Once again, the cam timing changes seem to help in the areas where the power-band is dipping (8000 RPM) or dropping off.