remapping ECU for low octane - Horizons Unlimited

**Chris Scott** · #1 3 Jul 2004

Not a BM specific question but there was nowhere else to put it - maybe you can help.

Not quite sur what I am talkiing about but - Octane booster/etc apart - on bikes with the right sort of electronics is it possible/viable/sensible to re-map your ignition electronics with laptop/software to retard ign for low octane fuel (like KTMs and 11xxGSs can do, sort of).

Or best just to leave it alone - the smarter ECU will work round the worst of the pinking?

Just a hypothetical question.

thanks

Chris S

**Frank Warner** · #2 5 Jul 2004

Some EFI systems have "knock sensors" - these will retune to suit the fuel used as well as the engines state of ware.

I think the R1200GS has one. But not the R1100 motors .. and I don't think the R1150 have one either.

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Few and far between would be OEM EFI systems with externally programable maps.
The motornics do not have an externally progarable map so you cannot tune these with an external pc. Some have alternate maps - you get to select which one but that is about it. An alternative is to change the engine position sensor position changing the timing. Similar to altering the timing on a vehicle with a distributor and points. Same princile applies to any EFI systems without knock sensors.

People are making their own EFI system to have programable maps - see http://www.jefferies-au.org/My16M/index.htm

PS EFI systems can suffer from heat vapour lock. Ask any early bmw K bike owner who has been in warm places with low fuel levels and a dirty petrol filter ...

[This message has been edited by Frank Warner (edited 04 July 2004).]

[This message has been edited by Frank Warner (edited 05 July 2004).]

**Chris Scott** · #3 5 Jul 2004

Thanks Frank - good answer.

Chris

**bmwjack** · #4 7 Jul 2004

Do you know anyone that has used these boxes?

Quote:

Originally posted by Frank Warner:
Some EFI systems have "knock sensors" - these will retune to suit the fuel used as well as the engines state of ware.

I think the R1200GS has one. But not the R1100 motors .. and I don't think the R1150 have one either.

-----

Few and far between would be OEM EFI systems with externally programable maps.
The motornics do not have an externally progarable map so you cannot tune these with an external pc. Some have alternate maps - you get to select which one but that is about it. An alternative is to change the engine position sensor position changing the timing. Similar to altering the timing on a vehicle with a distributor and points. Same princile applies to any EFI systems without knock sensors.

People are making their own EFI system to have programable maps - see http://www.jefferies-au.org/My16M/index.htm

PS EFI systems can suffer from heat vapour lock. Ask any early bmw K bike owner who has been in warm places with low fuel levels and a dirty petrol filter ...

[This message has been edited by Frank Warner (edited 04 July 2004).]

[This message has been edited by Frank Warner (edited 05 July 2004).]

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Jack
Rockhampton, Australia

**Frank Warner** · #5 8 Jul 2004

Suggest you contact him - see the site for details. They are not for bms, nor for the inexperienced!

[This message has been edited by Frank Warner (edited 08 July 2004).]