a power fc is next to a standalone ecu. where the emu is more of a plug n play ecu. Hence why guys who have the emu usually upgrade to a power fc lol.
so with the power fc there is a few extra features. I had a a write up about the difference between the 2. But i cant seem to find it right now. If i came across it ill post it up.
The Power FC is a stand alone ECU..
And the Ultimate is NOT a plug and play, its a piggy back
And there is no way i would upgarde to the PFC from the Ultimate.
For starters there is no knock control in the PFC!
As for which one is better, it depends on what you want from the car, what your tuner knows best, and how deep your pockets are.
it allows u to see the knock sensor reading via the pfc commander so u can map it safer!
alltho i think there is a knock controller on pfc for starlets...
i think Aga has..
I use both.
they are both great unit.
if they were same price I would choose PFC.
I would choose PFC for the simple fact it is a real standalone.
now you might be surprised to hear EMU has more features than PFC. EMU has launch control, it has dual map in memory that you can switch anytime. you can control a fith fuel injectors or even WaterMeth injection. it would be able to automaticly switch map if your WI system fails. it will allow your ECU to retard timing if it reads knocks (if you don't want to, then a knock adapter is available). EMU has datalog included, it can autotune with a wideband
So do not underestimate EMU, it is a great EMS that has more features than PFC.
some might like it better as they need one of its specific features.
Now PFC is a stand alone, it is plug and play. it has more cells to play with in your map.
the knock reading isn't really a prob to me. it will display knocs level on commander, and will switch on engin check light if it reads any level considered as knock.
I think EMU is a great EMS to start with as it is very user friendly.
but a stand alone stay a stand alone. PFC is a cleaner approach just for this fact.
EMU is probably one of the best piggyback computer if not the best. while PFC is one of the cheapest standalone.
granted emu is the best piggyback you can have
BUT
a piggy back is just a piggyback, O2 feedback from the oxygen sensor makes it almost impossible to tune AFRs in closed loop with the EMU as the stock ecu will keep trying to get back to stoichiometric........simply put, no piggyback can even compare to the control granted by a standalone, once the value is set there is no fighting back from the stock computer....
also, ignition timing with a standalone is absolute whereas with a piggyback ignition timing is a function of adding or subtracting to the base map's (within the stock ecu's memory) original timing, so when running +6 deg in the emu, u only know ure adding 6 degrees of advance, u don't know what u are adding it to so you can never get a grasp of the actual timing the car is running
for some this may suffice but i prefer to know exactly what i'm dealing with