Firstly apologies if this has been covered as I couldn't find anything specific to my application.

I'm looking at options for ECU to support upcoming performance upgrades and noticed people talking about wideband, launch control, two step etc while retaining the OEM ECU in this case ME7.1.1 or swapping uptown ME7.5.C.

My RS will have the following:
- Manual Conversion
- E85 Fuel System: 2000cc inj, -8 feed -10 return, 3x E85 450LPH pumps, adjustable fuel reg
- Upgrade 4" SMIC
- K24 billet turbo kit

The above will make 800/1000hp when running 98/E85.

As E85 requires a lot more fuel, if the ECU (either 7.1 or 7.5) can provide real time map changing and then adjusting fuel trims would be ideal. However I'd be happy with the ecu being triggered by a sensor detecting e85 so the ecu can switch to the e85 tune and then adjusting trims via WB 02 if possible.

The option to go Motec in parallel to the factory ecu is always an option however I'd prefer a single solution if the motronic can meet the demands.

I appreciate all the experts putting in their advise and experience from undertaking same or similar setups.