Flex Fuel/Fuel Mapping

Discussion in 'Mechanical - Engine, Gearbox, Exhaust etc' started by SteveKozy, Nov 19, 2020.

  1. Hi all

    Is it possible to run a flex fuel sensor to cope with changes in octane on the fly with a megane? Or even a switchable map (though less convenient)? Guess it would likely mean stand alone ecu.

    Got a bit of a dilemma and trying to work through it.

    Thanks in advance
  2. the ECU already allows for a range of octane level changes
  3. Thanks for the reply and sorry, i should have said, the car is not standard.

    It's a r26 running an rs275 engine and turbo on a mapped r26 ecu. So whilst I know it has knock sensor, i wasn't sure, with it being mapped, if those same allowances would be made?

    I've tried contacting the tuner but the company email bounces back an error. So doing some digging on my own as i am trying to plan a roadtrip and there are no 99ron pumps within 250miles...cutting it close.
  4. I think he means software that can detect fuel octane and switch maps accordingly?

    Or even just a manual way to switch maps accordingly?

    Either way, I don't think it's possible with original ECU, but you could run a boost control if that would help?
  5. You would need a half decent standalone with flex fuel sensor if you want to try something exotic.
  6. I've since found/been told, that with a mk3 rs ecu, a switchable map on the sport button is possible but alas i run a mk2 ecu.

    The car wont account for a change from 99 to 95ron fuel i don't think, hence my post. I'd be running a major risk of detonation i imagine? Would a boost controller work?

    So wondered how to cope with the issue of not having any 99 pump fuel anywhere near by, at any given point on this trip (or in the future). Surprisingly i thought more maybe had come across it. Seems not. Alas my trip is to the outer hebrides. Not many fuel stations running vmax
  7. Ideally what id like. I've used haltech and flex fuel in past in my stroked impreza. Just knew what the fuel was doing and ran accordingly.... Never seen and i can't find anything on, this being done in a megane though.
  8. If you are that worried about the fuel, why don't you buy some "Octane booster" to put in the tank when you fill up.

    Something like these, my car parts supplier also has stuff like this sure most do.
  9. Yes it will work, i have used it to restore bad fuel ( year old ) in the past
  10. Jobs a goodun'!
  11. Its one of the reasons i run fuel between 95 and 99 octane when i take it to be mapped, in the real world sometimes its not easy or convenient to get 99 all the time.
  12. I can assure you the absolute best octane boost is this stuff NF Octane Boost, will deffo up you 98 Ron to easy 99Ron perfect for places like Scotland and Spain where no 99.

    Attached Files:

    • NF.jpg
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  13. -Jamie-

    -Jamie- RSM Moderator

    Scotland isn't that bad for not having 99
  14. absolutely, awesome people, roads, food and scenery and as you would expect for a (thankfully) low population fuel stations are quite far apart and certainly don't cater for polluting tuned up boy racers expecting hi octane fuel
  15. I cannot wait to go. I love Scotland and never been that far north. The NC500 plus excursions is our tour.

    My mate from wick has done the route a bunch and just said to bear the fuel in mind. He drives a very hot impreza. So figured he'd know.
  16. -Jamie-

    -Jamie- RSM Moderator

    There's enough options for Super for it not to be a worry but I'd always take some booster just incase eb942672d81060442fd2dae281dacfbf.jpg 042a608a90e2a96a5ac58f72735fc274.jpg 40c815a79b28c736ced2a816e588731f.jpg e71335489b562dc8518c5d780c9caca9.jpg
  17. I don't imagine it's much different from wales where my folks live. About an hour away.
    Oh god I cannot wait! I hope it's as good as those of photos look??

    Octane booster is on the menu for after payday next week. Seems I can get some really good deals at demon tweeks or Roger Clarke.

    On another note. I'm glad you guys are more positive than some of the guys comments on pistonheads.

    1. Take another car
    2. Don't driver over 3000rpm
    3. Don't drive like a moron.
  18. -Jamie-

    -Jamie- RSM Moderator

    When are you going?

    I'd also recommend the NG booster, it's what I keep a few bottles of
  19. May 18th for a week.

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