NefMoto

I want to know if its worth looking into making it so that the alternator only charges the battery during cruise and engine deceleration. That could free up some HP during acceleration. I know the newer Mercedes do this. Can this be done with me7.5? I don't know where to look in the FR for this type of thing.

How would you do this without a clutch on the alternator similar to what the AC compressor uses?

Some cars already have PWM/ECU controlled voltage regulators.   ;)

oh, I know that, but not this one. lol

In theory, perhaps a relay could be connected to the alternator output terminals, and wired to the AC compressor clutch cutout?

Stupid thing to do. If you disable alternator you will at best get slightly above 12volt to fuel pump and ign coils when these really make use of high voltage. (during high boost and rpm)

it was explained to me by my buddy ( a Benz mechanic) that it doesn't disable the alternator, just maintains enough load to power the car without adding the load of charging the battery during acceleration. during deceleration the load on the alternator to charge the battery + maintain the load required for proper function of the vehicle works as a brake to slow the car down when in gear via parasitic drag from the alternator under load.

As far as a stupid thing to do...Mercedes has already implemented this idea on their production cars.

Well then, a relay to the battery then?

for?

run the AC compressor cutout line from the ECU to a relay that disconnects the battery, or switches to rectifier circuit that only allows current to run FROM the battery into the bus.

Then the alternator will not have the extra load from charging the battery.

I never said MB's solution was stupid.
Forget it and instead raise boost by 0.001 PSI :-)

I was thinking the voltage reg would be the "relay"

it already controls whether or not the battery gets charged.

I want to know if there is a map or something to tell the voltage reg what to do or if a function could written into the software file.

like what Drehkraft  said above.

Seriously, a 150A alternator running at 14V gives out 2.1KW or 2.8 HP, you really going to notice that?

In a N/A motor, yup :)

but yea, in boosted applications, doesn't seem like much.