Grid, Hockenheimring, 2018

FIA to stop F1 teams exploiting fuel flow loophole

2018 F1 season

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The FIA will make a new effort to ensure teams’ fuel systems comply with the rules after discovering a potential loophole which could allow them to exceed the flow limit, RaceFans understands.

At a meeting of the FIA Technical Working Group on Monday it emerged the FIA has concerns teams could use expandable hoses to create extra storage for fuel and therefore bypass restrictions on fuel use.

FIA restrictions limit both how much fuel teams can use in a race – 105 kilograms – and the rate at which it can be consumed – 100kg/hour. An FIA-specified fuel flow meter measures the rate of fuel use.

However fuel movement between the fuel flow meter and the engine is not monitored. Concerns have now arisen that teams could exploit this by using expandable hoses to collect surplus fuel when demand from the engine is low. This could then be used to send extra fuel to the engine when the fuel flow is at its maximum.

The potential gains from this are believed to be small. The FIA plans to address it by developing a means of checking fuel system compliance to ensure there is no excess storage between the pump and the fuel flow meter, and the engine.

The subject of Mercedes’ contentious rear wheel hubs was not discussed at the TWG meeting. Mercedes has not run its recently-introduced design in the last two races after fearing a potential protest from Ferrari over their legality in Austin, and despite stewards ruling the design legal in Mexico.

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Author information

Dieter Rencken
Dieter Rencken has held full FIA Formula 1 media accreditation since 2000, during which period he has reported from over 300 grands prix, plus...
Keith Collantine
Lifelong motor sport fan Keith set up RaceFans in 2005 - when it was originally called F1 Fanatic. Having previously worked as a motoring...

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27 comments on “FIA to stop F1 teams exploiting fuel flow loophole”

  1. I now wonder what kind of expandable fuel tubing they used.
    Flexible tubes like a snake which just ate a mouse, or metal ones constructed like a trombone.

    It might be the latter as I noticed that there are a lot fewer complaints about the sound of the PU’s ;)

    1. Lol, do other people picture the same drawing from “le petit prince” with the elephant in the snake when you mention that @coldfly.

      I must say that with this flexible hose thing it actually might make sense why FI would have had the “issue” on Ocon’s car – maybe they try to do this during the warmup lap (to have that little extra oomph at the start) but it somehow did not switch off in time?

      Don’t you love the ingenuity of how F1 teams find loopholes to eke out that extra one millionth of advantage they can get out of any rule :-)

      1. @bascb, @coldfly I certainly had that image in my mind :)

        Yeah, wonder if that’s what was going on w. Ocon, indeed. Still, I thought that already after 2014 (or 2015?) they forbade any and all collectors after the fuel meter, including flexible receptors; I assumed that included hoses, but, when ‘minimal’ needs a definition for front wing aero, I suppose ‘that includes any and all hoses’ isn’t too much to add here.

      2. I must say that with this flexible hose thing it actually might make sense why FI would have had the “issue” on Ocon’s car – maybe they try to do this during the warmup lap (to have that little extra oomph at the start) but it somehow did not switch off in time?

        Ah ha! Yes! That does make sense. It did seem odd that the engine management software would allow a driver to exceed the 100 kg/h flow rate, after all doing so would result in Disqualification (as did happen to Ocon, and I think also Riccardo quite some time ago). Maybe there’s a need to adjust the rate of maximum fuel flow, e.g. when doing “lift and coast”, but the software should automatically prevent a fuel flow rate above the legal maximum.
        The laughable part about this is the FIA mandated the use of a standard engine management system so they could peak into the software each team uses, so they should know if there’s a knob on the steering wheel that allows a driver to control the fuel flow rate, and if there is whether or not that driver could exceed the legal maximum fuel flow rate of 100 kg/h.

    2. I remember funny tale from nascar. They had specified the size of fuel tank but had no parameters for the fuel lines. So one team had big and long enough fuel hose to fit 5 gallons of fuel…

      1. Lol @socksolid. The spirit of finding a loophose to fill her up :-)

  2. The FIA […] discovering a potential loophole which could allow them to exceed the flow limit

    I’d be surprised if the FIA discovered this on their own.

    It’s more likely that someone is using it, and someone tattled; or (less likely) someone plans to use it and asked for a clarification in advance.

    In the case of the former, I’d be curious to know which teams.

    1. Could also be a lobby from the engine manufacturers. The ones who don’t get it done or where it seems to be a flaw in their design. I’m looking at Renault and Honda. We have seen the smoke from Ferrari in the early stages of this year, we have seen the engine retraction from Mercedes in Austin.
      Then again, this is a guess, it could also well be from Jimmy the janitor who excidentally told the janitor from an opposing team.

      1. @moustacho the smoke from the Ferraris is still there. Now visible at other Ferrari-powered cars, as I remember seeing recently at the back of a Sauber. Maybe not as visible as in the early races though…

        1. @bakano: Aha! They’re using expandable smoke to hide extra fuel as well. Or worse…

          What if they’re not only breaking F1 technical rules, but blatantly violating the Laws of Thermodynamics by converting the smoke back into racing fuel. Diabolical. If true.

          1. @jimmi-cynic, I was just mentioning that the smoke is there. No way I wanted to link the smoke with extra fuel storage…
            (the smoke is actually coming out of their recycle fluid exit, that other engines also have, just that the Ferrari 062 EVO engine produces visible smoke when releasing those fluids and others don’t)

          2. Its all smoke and mirrors!

          3. Jimmi’s username certainly suits his personality.

    2. @phylyp

      I doubt this was difficult to detect, unless deliberately hidden. Most cars use steel lines and a pressure damper. The pressure damper (or accumulator) has probably already been regulated as it requires stored volume. Flexible lines are avoided for good practice reasons, so their presence would have been noteworthy.

      What I’m trying to say isn’t really novel and shouldn’t have been difficult to comprehend.

      However, they might not have comprehended how beneficial little volumes could be. I suspect even a cm of extra storage would be massive over the race.

      1. I suspect even a cm of extra storage would be massive over the race.

        Indeed @slotopen.
        Every 1cm3 holds some 8g of petrol.
        This would be enough to get 10% extra fuel flow (and HP if operating at constant thermal efficiency) during a third of a second.
        That might not seem a lot, but 1cm3 is almost nothing (20 drops) and you can do this over and over again (after you lift the throttle).

  3. I thought this was a loophole that was closed a while ago…

    In 2015 there was a a rumour that this type of system was in play and monitoring was adjusted to watch the constant pressure of the fuel (and assumed that pressure would drop as any ‘stored fuel’ was used…

    1. Yes, that is why they now used “expandable hoses” so that the pressure would not go up and down, just the volume of the hose (slightly) increases to hold more fuel, surely finely monitored to keep within those minimal pressure tolerances that are allowed under the monitoring @maddme.

  4. Reminds me of NASCAR many years ago when the authorities put a strict limit on the size of fuel tanks to be allowed. However one ‘character’ consistently managed several more laps than anyone else with the same size of tank so the Stewards eventually called him in to have his tank removed and examined. The tank proved to be legal but the Stewards took so long about the process that the ‘character’ lost his temper & jumped in the car, started it up & drove off in front of the astonished Stewards. Turned out that the fuel ‘line’ from the tank to the engine actually held five gallons.

    1. Great story Neil Dockray, and goes to show that this sort of stuff can be expected in many avenues of motorsport (or all mechanical sports, looking at all the ways cross-country bikes are sometimes found to have a small linear motor inside the frame – no that’s not allowed, even if you weren’t caught ;-).

    2. The Unlimited Hydroplanes did similar when the rules implemented a fuel flow limit to try and even the playing field.
      The more fuel you give the Lycoming T55-L7, the more power it makes… and the quicker they blow up.
      The rich teams could afford several motors, the rest couldn’t.
      Teams were issued a calibrated fuel flow restrictor at the beginning of the weekend.
      The ‘creative’ teams didn’t mess around with expandable hoses or extra long fuel hoses.
      They pumped the fuel through the flow restrictor… and into another fuel tank under the deck.
      During the five minute warm up prior to the start of the race, the downstream tank would fill up.
      Then they had all the fuel they wanted for the race.

  5. Why limit the fuel flow in the first place?
    F1 has so many restrictive rules in place (that we often never hear about unless their being broken) that stifle innovation.
    Not to mention situations that arise as with the front wing rules that are currently being rewritten.

    1. Limiting furl flow rate is the easiest way to regulate and limit the power output of the IC engine.
      Without this, a 1,600 cc turbo V-6 could easily put out 1,200 HP in race trim and a whole bunch more when set up for qualifying.
      Restricting HP requires you either limit air flow through turbo with boost pressure limits, a waste gate pop-off valve or apply a fuel flow limitation. Simple and easy, for the most part.
      It also retains the incentive for engine builders to chase efficiencies to get more power from a given mass of fuel. That has been the man focus of all the manufacturers lately. Hence C Horner’s comment a while ago that the engine was effectively a diesel.

    2. Because rules are made by committees, and are always the result of:

      A) compromise
      B) forgodsakeletsjustgetitoverwithalready

  6. The ‘Diesel’ comment by Horner was referring to the oil burning that was going on, as diesel fuel is basically oil.

    1. TBW … likely you are right on that part, but what I understood C Horner was referring to was the use of high (and we do mean diesel region high) net compression ratios to result in an engine that is just on the edge of a compression ignition cycle. Basic engine theory correlates peak compression to efficiency. When you look at what the designers have been able to achieve, it is quite remarkable.
      A bunch of years ago, Nascar had to clamp down on rising compression ratios in the Cup motors. Understood to be upwards of 16 to 1. In F1, with more exotic engine management systems and custom fuels being formulated, they are likely well beyond this.

  7. This is exactly how mammalian arteries work – our arteries!

    They are muscular walled. So they expand and then contract during each ‘pump’ from the heart. Further, we have control over the tone – tension – in the arteries in part using nerve impulses. And…. The body can affect can have differential effects on arteries across the body at the same time.

    It’s proved a very valuable system!

    It has a significant effect on improving ‘fuel flow’, so-to-speak…..

  8. Being a skeptic at heart, I doubted that there would be any real opportunity to use a flexy or expanding fuel line to do anything significant in terms of circumventing the 100 kg/Hr limitation.
    The rules are also very specific to forbid the use of accumulators or any other “devices” that will store fuel or bypass the measurement and limitation on fuel flow. So if you were going to do anything sneaky, you will need to hide it really well.
    Having finally completed my responsibilities for the Procrastinator’s Association, West Coast Chapter, I banged up a small spreadsheet to figure out how much benefit there might be for a flexy-fuel line from a pressurized Fuel Flow Meter to the inlet of the high pressure injection pump. WOW … was I surprised.
    If the fuel line is 1 m in length, 10 mm ID and it expands under pressure by an additional 20%, to 12 mm. What happens.? Volume of the 1 m line is 78.5 cc increasing by 44%.
    Seems the incremental volume increase is 34.6 cc and with a regulated flow rate of 27.8 cc/sec (100 kg/Hr) this equates to a flow rate increase (and corresponding HP increase) of 10% for 12.4 seconds or a 25% increase for 5 seconds. This is each and every pressure cycle, but there will need to be a control mechanism to bump up the pressure and let it down in sync with the throttle application (engine demand).
    Increase the difference or flex in fuel line diameter for the high and low pressure cases or change the length of the fuel line and the numbers would also change, but as a first cut, this Myth has definite validity.

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