Dyno day. OFT Stg 2+ E85 Gruppe-s Uel
 

a

Mustang dynos typically read lower compared with dynojets, usually around 12-13%, so you'd probably have made around 168-170 whp stock and 186-189 whp on e85 with a dynojet.

That torque curve looks pretty good too. No more torque dip and you're making 90% of peak from roughly 2700-7400 RPM, which is a wide spread.

a

Those numbers will improve with all e85 and a little time for the tune to settle in.

12% gain, pretty low for E85, header, tune. Especially catless header.
OFT E85 is not flex fuel you are supposed to run tank down as low as possible.
It’s possible your E85 percentage was rather low, especially if it hadn’t mixed fully yet, and even after mixing 8gallon E85 (assuming its not low E85 % like a lot actually are) and 4 gallons of 91 is E60. Which is just out of the flexibility of OTS E85 tune, either case would cause you to run very rich on OTS E85 tune reducing potential power. Did you happen to record your AFR and or fuel trims on the run?

a