Back when Ferrari ran their engine in the LaFerrari mule, I commented on what appeared to me to be a striking silence as the car was cornering.
this article at Omnicorse.it describes two initiatives from Ferrari's engine team.
The first talks about how the team cuts off fuel to the engine as they go off throttle - yet they still manage to lube and cool the piston chamber without the flow of fuel. This would be a significant fuel saving and very difficult to copy.
The second is to do with the use of the exhaust and getting "free" power (outside the 33 second allocation) by dropping the engine below 7K and using the turbo ERS-H, bypassing the batteries and directly powering the ERS-K unit.
These are unsubstantiated and pure speculation at this stage. There was definitely something in terms of sound when off throttle when they ran the engine in the LaFerrari mule. Also there is clearly a different sound that the Ferrari engine has on downshift/off throttle that everyone confirmed at Jerez testing. So something is going on there, but exactly what??