fuel flow - and cheat | FerrariChat

fuel flow - and cheat

Discussion in 'F1' started by maulaf, May 10, 2015.

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  1. maulaf

    maulaf Formula 3

    Feb 24, 2011
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    There has been rumours for a while that some teams 'cheat' or loophole around the fuel flow regulations permitting short bursts of higher fuel flow = increased power. Someone posted an article this weekend that the FIA has toughened up the fuel flow measurements to curb this and found teams were still finding loopholes... the usual race.

    I read elsewhere now that people suggest this affected Ferrari, hampering their performance at Barcelona. Does someone perhaps have reliable information on all this? If they design engines around such loopholes it could turn into a pretty mess if that is affected mid-season.
     
  2. Far Out

    Far Out F1 Veteran

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    #2 Far Out, May 11, 2015
    Last edited by a moderator: Sep 7, 2017
    I do not know how fuel flow in the car is measured, but yes, it is possible to cheat in that way in principle.

    Every sensor out there has certain dynamic boundaries. Attached you'll find a random picture of a low-pass step response to illustrate the behaviour: Imagine it would be possible to increase the fuel flow infinitely fast, like the blue line in the picture. It suddenly jumps from 0 to 10. The sensor, green line, will not be able to pick up the change that fast and will follow a bit slower. In the area where the blue line is above the green line, you're putting more fuel through than you measure.

    Now of course it's not possible to have sudden jumps in fuel flow, but all you need is to be faster than the sensor. This could be achieved by example by building up and suddenly releasing fuel pressure.

    Getting correct readings from such sensors is not easy even if you try your very best to get correct results (speaking from experience here :rolleyes: ). I find it totally plausible that it's possible even with the restricted ECUs to manipulate stuff there.
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  3. Fast_ian

    Fast_ian Two Time F1 World Champ

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    Thanks Florian! Very interesting.....

    Per the FIA, there is only one homologated fuel sensor right now. Remember the debate about a second coming along?.... Didn't happen.;

    http://www.fia.com/sites/default/files/regulation/file/LT%2045-On-Board%20Fuel%20Flow%20Meter.docx

    And here's the data sheet for the thing;

    http://gillsc.com/content/datasheets/gill-sensors-fuel-flow-meter-2014?v2.pdf

    Seems its measuring *internally* @ 1khz, but it's down to 100hz by the time it hits the CAN bus.....

    Could some quick 'dy/dx' give us an idea of how much go juice they could squeeze thru without setting off alarms? Assume 100hz ('plus smoothing' :eek:) and 10k rpm. ;)

    Cheers,
    Ian
     
  4. Igor Ound

    Igor Ound F1 Veteran

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    #4 Igor Ound, May 11, 2015
    Last edited: May 11, 2015
    omnicorse.it

     
  5. Far Out

    Far Out F1 Veteran

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    Thanks Ian for finding the documents! The key is in the FIA sheet:

    Will do some calculations later on ;)
     
  6. DF1

    DF1 Two Time F1 World Champ

    WOW! FAB report. Love it! :)
     
  7. Far Out

    Far Out F1 Veteran

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    *shamelessly patting myself on the back* ;)

    However, the report is not really clear, they talk about fuel pressures, but the kg/h numbers are a mass flow...

    Edit: Maybe Charlie meant that if the fuel mass flow is between 90 and 100kg/h, the pressure must stay constant.
     
  8. Igor Ound

    Igor Ound F1 Veteran

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    What I read is that they kept pushing fuel even during braking to have it in double amounts when straight back on the accelerator. But that was prior to China.

    This sounds more similar to the sensors issue Red Bull had with Whiting last year at the Australian GP
     
  9. Fast_ian

    Fast_ian Two Time F1 World Champ

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    And deservedly so..... ;)

    I knew you'd pick up on that! ;)

    I'm assuming (hoping?) it's more a function of Google translate than what he actually wrote.

    Here's what he (apparently) wrote;

    Edit; So another much deserved pat on the back for Florian! :)

    Cheers,
    Ian
    FIA clamps down on ?trick? F1 fuel systems | FORMULA 1 news | Motorsport.com
     
  10. Igor Ound

    Igor Ound F1 Veteran

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    Just read they were using expanding elastic tubes able to work as reserve pockets and accumulate extra fuel after the sensor's position, so releasing it when needed at increased pressure.
     
  11. Fast_ian

    Fast_ian Two Time F1 World Champ

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    Again, a great explanation.

    However, it's been troubling me a little - I think your blue line is more analogous to Charlie's digital feed - it may be a fine 'step', but it's still digital. Your green line however is more analogous to the 'real world', where changing physical stuff takes time.

    Ergo, I'd put the green line "above" the blue - more fuel without disturbing "Charlie data". ;)

    Cheers,
    Ian
     
  12. Far Out

    Far Out F1 Veteran

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    But then the fuel would have already passed through the sensor at normal supply pressure and had been measured properly. I'd place the elastic tubes upstream of the flow sensor so fuel could be accumulated under high pressure during braking. When accelerating again, the pressure could be released, causing fuel flow dynamics that would be faster than the sensor could measure.


    No, the principle has nothing to do with the way the signal is transmitted further downstream the signal path. The picture with the blue line was meant to illustrate that the sensor (green) can not follow a - hypothetical - instantaneous jump in the underlying physical signal. Nothing with digital 0/1 in there ;) In reality, the blue line would of course also not be a straight jump from 0 to the final value.
     
  13. Mulehead

    Mulehead Formula Junior

    Jun 6, 2012
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    The real problem is the FIA makes these rules and are surprised when people find a loophole. There should be only one rule if they want to go green just say to the teams you only have ten gallons to make you car get Thur a f1 grand prize race . Impo the fuel pressure and flow rate does nothing to improve fuel economy
     
  14. stever

    stever F1 Rookie
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    Remember when racing was about going fast?

    (Then there's this.......There are going to be speed limits at the 24 Hours of Nurburgring......racing has well and truly died; I'm reminded of it all too often.)
     
  15. maulaf

    maulaf Formula 3

    Feb 24, 2011
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    Thanks guys. This as interesting.
    How is measuring pressure additionally going to help? Because higher injection volumes would require higher pressure to overcome the pressure drop over the injection nozzle?
     
  16. ricksb

    ricksb F1 Veteran

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    "Innovation and ingenuity...something that must be squashed. Immediately"-FIA representative
     
  17. Mitch Alsup

    Mitch Alsup F1 Veteran

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    We have not seen 917 speeds (~250 MPH) at leMans for decades; all that chicanery.
     
  18. Mulehead

    Mulehead Formula Junior

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    I'm a f1 all my life I could tell you have the rules now . Impo who cares what the fuel pressure is or more stupid how it's measured how much does these rules cost the teams when all you have to say is you get 5 gallons of gas to race your leaf blower motor powered f1 for the race distance
     
  19. Igor Ound

    Igor Ound F1 Veteran

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    It's much simpler done downstream.
    You let the fuel pass through at the correct rate, even when you don't need it, by letting it fill up the elastic tubes instead without using it.
    When back on the accelerator you keep pumping fuel in at the same rate, but already have some in the system pressurised, waiting for an opening.
    Think about it as a water tap and a glass. You keep the tap open at the same rate but when you don't need the water in the sinc, you fill up your glass (elastic tube). When the water is needed again, you empty your glass, plus you have the tap going back into the sync.
    This is what apparently was happening prior to China.
    Not sure how they are cheatng again though.
     
  20. Igor Ound

    Igor Ound F1 Veteran

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    I think the theory behind the consistent rate is useful.
    If you could manage it as you wanted we would see races where at the start everybody pushes at max fuel to get to the first corner first and then the first position driver slowsright down just worrying not getting passed.
    Only overtakes would happen at the pits and even the drs would do little as the driver in feont could just burn more fuel and keep its position.
    At least now they kind of push for the whole race length
     
  21. Fast_ian

    Fast_ian Two Time F1 World Champ

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    All understood! (Really..... ;))

    However, does the sensor send 'actual' flow rates? Or does it send "arbitrary" numbers which are then post-processed by the ECU?

    With apologies for it;

    A. Not being a Florian level, labelled graph. ;)
    B. Being a PDF. Very limited drawing options on the iPad.

    Here's what I'm getting at; data sent to Charlie is a digital, hence stepped, feed as shown in black. We'll leave any hysteresis out.... Is the sensor itself sending, eg, "current flow is 90kg/h" or "current flow is "some number" which is then used by the ECU to calculate the actual rate?

    If the latter, then it seems to me we could squeeze more juice thru by "following" the green line...... We're "above" the rate reported to Charlie, but below the rate that would take us to the next step? Obviously vastly oversimplified - I'd guess some form of sine wave running at a +ve slope at about 45degs would be more practical, but I think you get the idea......

    Cheers,
    Ian
    PS - seems I've got to re-subscribe to add an attachment..... Coming soon.....
     
  22. Fast_ian

    Fast_ian Two Time F1 World Champ

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    #22 Fast_ian, May 12, 2015
    Last edited by a moderator: Sep 7, 2017
  23. kraftwerk

    kraftwerk Two Time F1 World Champ

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    Excuse me for cutting to the chase here, but is it illegal or not...or just a clever work round..?
     
  24. Fast_ian

    Fast_ian Two Time F1 World Champ

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    There's the million $ ($100MM?) question.......

    I could be *way* off base here - I'm sure Florian will be along shortly with his wisdom - but, once again, it seems to be a question of 'interpretation'.

    If I'm even in the ballpark with what they're doing (& I admit I may not be!) then the rates reported to Charlie are 'under' the limits, but if they can squeeze more fuel thru without going to the next 'step' they're getting an advantage without breaking the rule as written......

    Whether this yields a significant amount more fuel in is another question - Florian said he'd run some numbers and report back.....

    Cheers,
    Ian
     
  25. kraftwerk

    kraftwerk Two Time F1 World Champ

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    Cheers Ian, I get ya, so at min it's still in the air.
     

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