I've not heard, but normally more power means more fuel !
They are a very basic engine with very little in the way of easy added power.
I believe Whipple also do a ECU tune.
If you find out any more information I would also be very interested.
If you want power the Whipple Supercharger is the only way forward for an add on. But at $12,000 its a big outlay. They claim over 120hp gain though !