I did some dynoing on both ACN 91 and VP 101 unleaded.
Even after multiple pulls, there was very little power difference between the two fuels. With the early pulls on 101, the ECU attempted to advance timing slightly, and ended up sending knock and sent the advance multiplier down, actually resulting in lower numbers on 101 for quite a while, before getting back up to 91 levels.
Also, on 91, 4 pulls were needed to stabilize the output; the ECU was dumping a ton of fuel up top initially. Each successive pull resulted in the ECU dumping fuel later, until it wasn't dumping fuel at all.
This is the same dyno all the CSG Ace header dynos are performed on; a 2013 dynoed about 165whp here.
I'm tempted to see how long the power carries with a higher redline...
