all piggybacks alike can certainly influence the close loop AFR to a certain degree but not overcome it

 

That's not true. The Greddy Emanage Ultimate can NOT in ANY WAY change the AFR your ECU shoots for in closed loop. The AEM F/IC has COMPLETE control over the target AFR in closed loop.

I do not know about the F-Con, as the tuning software and details are only available to authorized dealer$.

 

"Target AFR" does not = complete control.

The F-CON iS's AFR is 12-14 in boost then jumps back to 14.7 to 15.2 or higher in idle.

 

What about the AEM allows it to overcome closed loop? Is it the way it is wired in? Something else?

 

The AEM F/IC taps into the Nernst Cell line on the stock LAF (lean air-fuel) sensor. Since the stock sensor is current based, the AEM is able to alter its feedback to the ECU by injecting / shunting current from the circuit.

When I said complete control, I meant that you can adjust the target Air:Fuel ratio to whatever you want at any load / RPM breakpoint. The Emanage Ultimate cannot do this as far as I know, and the HKS may or may not be able to do this. The AFRs seen on stock HKS kits at WOT have nothing to do with wether or not they can control closed loop. The way to know that is to see what the AFR does while rolling onto the gas at LESS than full throttle while entering boost. If the AFR drops below 15.0:1 consistently and smoothly, it can control closed loop. If it stays up in the stoich range, then it can't / they haven't implemented it in the stock tune.