Difference between AU XR6 and Fairmont/Fairlane Ghia

[Fairlane Al]

Does anyone know if there's a difference between the ECU in an XR6 and a Fairlane with the VCT engine?

I know the Fairlane has the power/economy button as opposed to the adaptive shift the XR6 has, but is that the end of the differences in the computer? The 4kw difference between the XR and the Fairlane is I am told, due to the quieter exhaust which shouldn't really come into things as mine has a full sports exhaust system.

The reason I ask is I feel that compared to my brother's XR6 ute, which is only just a regular XR6 and a friends XR6 VCT that I have driven, the Fairlane is not quite as quick off the mark and gearshifts are much slower, softer and smoother as opposed to both the XR's I've driven which felt much firmer and quicker to shift, almost as if they're shift kitted. Both of those are Series I cars and mine's a series II, which I would expect means mine should have more power if anything? I almost universally run mine on 95 or 98 octane fuel as does my brother, my friend I am not sure of.

Mine's stock except for a 2 1/2 inch exhaust and Genie extractors, my mate's has Pacemaker extractors, they look like 4499s and I believe it's running a 2 1/2 inch exhaust and my brother's is running stock manifolds and what I am told is a 3 inch catback but I suspect it may actually be a 2 1/2 inch. I doubt this would make much of a difference and it doesn't really explain the gear changes either.

If there is a difference in the computers, is it possible to transplant an ECU from an XR6 into my car or do I need to get it retuned?

Thanks, Alex.