[Tech Issue] Fuel and Flow and Sensors, oh my!

[Teretonga]

Originally Posted by ciscotex

FWIW, a couple more articles on the background and implementation of fuel flow restriction:

http://www.racecar-engineering.com/t...ow-is-limited/

http://www.racecar-engineering.com/t...w-meters-work/

I think I like the idea of restricting fuel flow rather than air to the engine, but hope the questions about reliable measurement are sorted quickly. Looks like Toyota may have a workable system for the Japanese series, but, ironically, are obliged to use the controversial Gill sensor in LMP1.

If Red Bull actually argues and wins their appeal on the basis that Charlie's opinions don't constitute actual, enforceable rules, then I can see the whole series quickly descending into anarchy and chaos. Very interesting for all of the wrong reasons.

http://www.autosport.com/news/report.php/id/113091

In any event, I suspect the manufacturers love this approach, as it allows them to genuinely work toward road relevant efficiency. While I'm not sure how much of road relevance will come from F1, the sports cars are likely to yield some real world improvements and give the makers a reason to participate in motorsports other than marketing.

Paul

I don't think so, unless the FIA completely messes it up.
1. Charlie was not on the stewards panel.
2. The stewards only adjudicate on matters referred to them
3. The steward's authority is restricted in some places by the constrictions of the rules and what they actually say.

So the problem Red Bull are arguing about is more with the way the rules are written and where the FIA is ethically wrong is trying to say they are the ones who determine what evidence can be used to verify your fuel flow.

As an adjudicator (not F1) my opinion is that the FIA is treading in places where they should not go with some of their rules.

Red Bull see's it in a similar vein.

[ciscotex]

Originally Posted by Teretonga

... the FIA is treading in places where they should not go with some of their rules.

So what else is new?

P

[wnut]

Thanks for the above articles from Racecar engineering Paul.

A very interesting read.

I take it the FIA introduced this reg:

"5.10.4 Only one homologated FIA fuel flow sensor may be fitted to the car which must be placed wholly within the fuel tank. "

Because they were concerned that their fuel flow sensors would contradict one another, proving that neither of them were accurate.

This affair needs to come up with a whole bunch of answers.

"Horner says that Red Bull was left with no other choice than ignoring the drifting fuel-flow sensor rate during the Australian GP."

from
http://www.autosport.com/news/report.php/id/113091


"DRIFTING"

Nice one, NOT!

[Pingguest]

Red Bull have reported new issues with the fuel-flow sensor. They acknowledge that they are in awkward situation, but say other teams are facing the same problems.

Last night I read that Gill Sensors guarantee that 53% of all their sensors are within 0.1% accuracy of reading, while 92% are within a accuracy range of 0.25%. The accuracy of the remaining 8% sensors is unknown but likely to be far from accurate.
The figures stated above prove the technology is too immature to allow a fair competition. Considering the high interests that are at stake, the FIA should act quickly and resolutely. Even an (temporarily) abolition of the fuel-flow limits should be considered for the sake of fairness and thus the credibility of the sport.

From a safety, relevance and cost-efficient point of view a fuel-flow restriction is necessary or at least desirable. The reports on Toyota's fuel-flow restrictor are hopeful and this alternative should be put on table.

[Adam43]

Originally Posted by Pingguest

Last night I read that Gill Sensors guarantee that 53% of all their sensors are within 0.1% accuracy of reading, while 92% are within a accuracy range of 0.25%. The accuracy of the remaining 8% sensors is unknown but likely to be far from accurate.

Sounds like a normal distribution being reported in the press by someone who doesn't know anything about statistics.
Was it Mark 0.001s Hughes?

If so it is very unlikely the remaining 8% are that much more inaccurate.

As we are know talking about probability it is impossible for this to be settled by a public debate and even less likely to be settled by press releases.

[b1ackcr0w]

I think the FIA have been unwise not to get this wrapped up and an appeal heard before another race happens.

[Pingguest]

Adam, could you explain the statistics a bit further then? As a lawyer I am not really into that science.

[Adam43]

You can't actually tell exactly from the information, but it is likely it follows a 'normal distribution' of values. A normal distribution, or spread, of measurements tend to be clumped around the average, with an ever decreasing chance as you move away from that average.

Statistically you'd talk of the chance of being withing a standard deviation from the average. You could describe the chance of being with 0.1 as 53%, or 0.25% as 92%. If it is following a normal distribution, which is reasonable it probably means something like 99.95% are withing 0.5% of the measurement.

Look up normal distribution or bell curve, should give some background, I guess it is the mathematically way to quantify 'reasonable doubt'.

The reason I brought it up is the comment 'the remaining 8%...'. It is most likely these are still close to the mean, rather than 'likely to be far from accurate'.

I hope that makes a bit of sense, I'm a little tired at the moment. My job does involve this kind of statistics on measurements that I suspect have much greater uncertainty and certainly less repeatability.

How much impact 0.1%, 0.25%, or 0.5% variation in flow rate has on the power of the engine I do not know. I guess if it is 20hp we should worry, but if it is 2hp out of 600+ I think it is a non issue to take your flow rate down by 0.5% to leave you with a 1/500 chance of contravening the regulation (say).

I'd be interested to see the article to know if I'm being unfair or not.

[miatanut]

Would it be possible to flow test the sensors, putting them through a sort of dynamic test and know what kind of results a particular sensor produces?

You would be using another "reference" sensor to evaluate the tested one. I realize the reference sensor will probably drift over time, but I'm wondering if there is a way to find the bad eggs and throw them out, or the bad eggs can get sold to the general public for measuring the flow of whatever, and F1 gets the cream of the crop.

[Richard C]

Originally Posted by miatanut

Would it be possible to flow test the sensors, putting them through a sort of dynamic test and know what kind of results a particular sensor produces?

You would be using another "reference" sensor to evaluate the tested one. I realize the reference sensor will probably drift over time, but I'm wondering if there is a way to find the bad eggs and throw them out, or the bad eggs can get sold to the general public for measuring the flow of whatever, and F1 gets the cream of the crop.

I am not a calibration expert, but plus or minus, I would expect that this is pretty much what I would expect the calibration process would be today. Immediate problems is having a reference that you (and everyone else) can trust and representative simulations of the dynamic conditions.

And to Adam's point above they will all not test/calibrate out the same. Some will be more accurate than others and even the cream of the crop will likely follow some type of normal distribution.

Richard

[miatanut]

Originally Posted by Richard Casto

And to Adam's point above they will all not test/calibrate out the same. Some will be more accurate than others and even the cream of the crop will likely follow some type of normal distribution.

Richard

Agreed, but if they are within a +0.25% and -0.25% range, if the HP varies in proportion, that's less than four horsies between the best and the worst. The engines themselves probably vary four horsies between engines of the same spec.

[aneesh99]

Well, now that Porsche is complaining about it as well, I think the FIA have a bit of an issue on their hands now.

I fear we may hear more about this after the P1 teams are done testing at Paul Ricard. Red Bull might actually have a very strong case. That being said, it always seems that it's Red Bull falling foul of the rules. Hmmm....

[ciscotex]

Originally Posted by miatanut

Would it be possible to flow test the sensors, putting them through a sort of dynamic test and know what kind of results a particular sensor produces?

FWIW, apparently this is exactly how they are calibrated by/for the FIA according to this link:

http://www.jamesallenonf1.com/2014/0...nd-themselves/

Apparently, Red Bull's alternate methodology wasn't correlated to the reference sensor, so I suspect they're in trouble re: the appeal.

In any event, if anyone doesn't abide by the FIA guidance re: offsets, etc., like Red Bull in Australia, I hope they just pull out the black flag during the race, as opposed to DQ'ing them after the fact.

Paul

[JeremySmith]

Originally Posted by ciscotex

FWIW, apparently this is exactly how they are calibrated by/for the FIA according to this link:

http://www.jamesallenonf1.com/2014/0...nd-themselves/

Apparently, Red Bull's alternate methodology wasn't correlated to the reference sensor, so I suspect they're in trouble re: the appeal.

In any event, if anyone doesn't abide by the FIA guidance re: offsets, etc., like Red Bull in Australia, I hope they just pull out the black flag during the race, as opposed to DQ'ing them after the fact.

Paul

Paul as you and I have discussed, they should have black flagged him during the race..It does not do F1 any good at all to have the finishing order of the race decided in a court room..

There is way too much controversy, I can't think of any other form of motor sport that has these many problems time after time it seems, correct me if I am wrong...

[ciscotex]

Jeremy,

Agree 100% on both points.

P

[Pingguest]

The FIA will not drop the fuel-flow limit, because that is considered too dangerous; speed differences will become huge.

I do not buy that, as in the 1980's such an accident did not occur despite lacking a fuel-flow limit.

[wnut]

Originally Posted by miatanut

Agreed, but if they are within a +0.25% and -0.25% range, if the HP varies in proportion, that's less than four horsies between the best and the worst. The engines themselves probably vary four horsies between engines of the same spec.

If these flow filters are this accurate and the results are repeatable why are the teams not allowed to fit them in series and compare the readings?

Drifting readings just indicate inaccuracy!

I see Ricciardo's sensor failed in Malaysia and the FIA agreed to use the RBR figures!

[Greem]

I believe it was the other way round: the sensor failed and RBR agreed to use the FIA's correction factor on their own readings. That was precisely what they refused to do in Melbourne, hence the saga we're now embroiled in.

[Richard C]

Originally Posted by wnut

If these flow filters are this accurate and the results are repeatable why are the teams not allowed to fit them in series and compare the readings?

Drifting readings just indicate inaccuracy!

I see Ricciardo's sensor failed in Malaysia and the FIA agreed to use the RBR figures!

I haven't had time to search for details, but I would assume that if a sensor "drifts" over time, that RBR could go to Charlie and say "look at the trend of the FIA flow sensor values vs. what our fuel model says". If the two don't have a relatively consistent offset (such as the flow sensor gets worse and worse over time, wanders around, etc.) then they have an argument to ask Charlie to let them stop using the sensor. This is all during the course of a session (qualifying, race) of course and not in general.

I would assume that whatever happened to Ricciardo's sensor in Malaysia followed the existing guidelines for a sensor failure (I still would love to read the technical directive that lists that procedure). I understand it correctly, it was to fall back to the values provided by the team (Maybe as Greem says there was also an offset applied), but the action was at the direction of the FIA and not at the teams choosing. I think some here equate that fallback option to assuming that the FIA considers the teams data to be without question. Rather, I think the FIA considers that data to be of last resort and better than asking the team to retire the car. Ultimate accuracy of the team's flow model remains an open question that is somewhat of a dead horse at this point.

I haven't looked at the lap time data for Ricciardo prior to his retirement, but overall, it seems interesting that RBR didn't do too badly (Vettel in third) given they apparently decided to race to the regulations. That last statement is not meant to be inflammatory, but rather its hard to word it differently unless I tap dance around the truth.

Running to the regulations and performing well will hurt whatever case RBR thinks they have regarding the Australia race appeal.

Regarding the DSQ of Ricciardo in Australia, during the Malaysian race Steve Matchett made a comparison to the 1995 Brazilian GP fuel issues. I can't remember the details from that far back, but I believe the Benetton and Williams teams were DSQed due to the fuel used during the race not matching prior fingerprints submitted by Elf, but analysis of the fuel later determined that while it didn't match the earlier sample provided by Elf (per the regulations), it also did not provided a benefit. So the team didn't get back any constructors points, but the drivers did get their points back. Someone also mentioned that there is no prior situation in which a team has circumvented the rules and came out on top during an appeal?

Anyhow, I think there is a slim chance that Ricciardo might get his points back. I see no chance for RBR getting any constructors points. I think the reason its difficult for Ricciardo to get any points back is because he likely did get a performance benefit (or a case can be made to say he did) during the race.

Richard

[Adam43]

Trouble is, as you say, I think that Ricardo did get a little advantage, making it different to Brazil 1995.

[miatanut]

Originally Posted by wnut

If these flow filters are this accurate and the results are repeatable why are the teams not allowed to fit them in series and compare the readings?

Drifting readings just indicate inaccuracy!

I see Ricciardo's sensor failed in Malaysia and the FIA agreed to use the RBR figures!

The way it was described, it sounded like that was their accuracy distribution as they are sold to anybody. We don't know that F1 doesn't get the very best of the lot. I think the issue is that +/- 0.25% is pretty good, but Red Bull is a team that has become successful by doing everything to the highest level of accuracy possible, and to them +/- 0.25% may be kind of shabby. Still, sometimes the 0.25% will be in their favor. It won't always be against them. I don't expect to hear a peep out of them if they get a "good" sensor.

The only thing you can be sure of, is that if you run two sensors in series, they will say different things. I don't get a vote, but I would be in favor of two in series. If the differences are significant, after the race you can test both and see which was more wrong. But, if it changes a race result you get screaming from race fans.

Maybe the rules need to be amended to state a +/-0.25% (or some stricter tolerance) will be considered "normal" and if a team's sensor tests in that range, they need to just shut up about it. If it tests outside the range there is an appeals process.

There is no perfect accuracy on this planet. It really comes down to defining what is considered to be an acceptable tolerance.

[Teretonga]

Some light at the end of a tunnel?

http://www.pitpass.com/51225/Fuel-fl...to-be-scrapped

[JeremySmith]

After all that ....

[321Go]

Originally Posted by Teretonga

Some light at the end of a tunnel?

http://www.pitpass.com/51225/Fuel-fl...to-be-scrapped

That light is you see at the end of the tunnel is just the sun rising this morning. Today being the 1st of April.

[wnut]

Originally Posted by Teretonga

Some light at the end of a tunnel?

http://www.pitpass.com/51225/Fuel-fl...to-be-scrapped

If this is an April fools' day joke, whoever put it together pretty well has the template for what I would expect to happen!
You disobeyed the rules, disqualified, our sensor is rubbish and we cannot police the rules as written, no fuel flow limit from now on!

Schumacher passing Alonso under "green"!