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Tps VE and flex fuel

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Hi i am planning to run flex fueling on an s54 bmw engine which has been turbocharged. The engine still retains its ITBs and has active double vanos. I plan to tune the engine using VE based fuel tables with throttle position as the load axis, load=map as equation load source. Will this cause any issues?

What ECU are you using? What flex fuel support does it have?

Provided the ECU offers sufficient flexibility in the flex fuel strategy, this should present no issues. Assuming the VE table is accurately tuned, the ECU doesn't really care if you're using TPS or MAP as the load axis. In my experience ideally you'll want either a second VE table or a trim table that you can blend in as the E% varies. While in theory you should be able to get away with a single VE table and just define in the ECU how the fuel properties change with E%, my experience is that this rarely deals with the changing fuel characteristic completely and will leave some remaining fuelling error.

That is good to hear! I will be using a maxxecu. It has VE based fuel tables with a lambda target table. It supports flex fuel and the ethanol percentage can be used as a table axis. There are plenty of extra fuel,ignition and boost tables so i think all should be well.