Blue Flame in Sinsheim

[TrickyDicky]

Robin,

Have you tried explaining averaging the times for the two runs and then converting to a speed, versus averaging the speed numbers themselves?  And how it can lead to different records with different speeds from the same pair of runs?

[MAYOMAN]

Really fun discussing this!
And, at the end of the day, mathematically speaking, there were only four significant figures (the recorded times) in the equations, so we can only go four digits anyhow. That is, mathematically.

[Malcolm UK]

The FIA rules are now quite clear on how to calculate the record speed(s) from the times, recorded over the mile and/or kilometre, to an accuracy of 1/1000th of a second.  They do make a positive statement that "it is not authorised to correct, round up, or modify the times actually recorded".

(Appendix D to be found on the FIA website holds the details).

The conversion of distance uses only the '1 mile equals 1.609344 kilometre', with the number used as a multiplier or divider as it is written.

Malcolm, Derby, England
 

[TrickyDicky]

The FIA rules are now quite clear on how to calculate the record speed(s) from the times ...

The relevant text is quite brief, so I will quote it in full.

• Flying start :
  
  Record time with an accuracy of 1/1000th of a second and calculate the mean time with an accuracy of 1/1000th of a second.
  
  Calculate and record speed with an accuracy of 1/1000th of mph or kph.
  
  Convert speed thus calculated to kph or mph.
  
  
• Recording and calculation:
  
  All times must be recorded up to 1/1000th of a second.
  
  If the timekeeping equipment has an accuracy greater than 1/1000th of a second, its precision shall be set to record times to the 1/1000th of a second, with no rounding off, to allow direct use of all readings.
  
  The speed must be calculated and recorded from the time thus recorded, and only the result up to 1/1000th of mph or kph shall be retained with no rounding off.
  
  To convert from mph to kph, multiply by 1.609344,
  
  To convert from kph to mph, divide by 1.609344.
  
  The converted speed must be calculated and recorded up to 1/1000th of mph or kph with no rounding off.

Whilst it is mostly clear, I have two problems with this.

1. There seems to be an assumption that expressing times to 1/1000th of a second means that the resultant speed will be accurate to 1/1000th of mph or kph.  This is arithmetically incorrect, as demonstrated by the speed calculations for The Blue Flame discussed above.  Depending on how the time values are manipulated, the kilo record can be 630.388 mph or 630.478 mph (i.e. a variation of 0.090 mph) from the same base data.

2. What does “no rounding off” mean?  I understand truncating, rounding down, rounding up, and even plain rounding, but not rounding off.  After pondering this for some time, I think “no rounding off” has the same meaning as “truncating”, but happy to be corrected on this.  Sometimes it helps to look at the French text (in this case “sans arrondi”), but that does not help me.  Mind you it’s more than 40 years since I last studied French and I wasn’t very good at it then!  Perhaps there is a French-speaking mathematician reading this who can comment??

The overall effect of the FIA’s speed calculation is to slightly increase a quoted record speed above the “true” speed.  In a sense this does not matter, but I find it unsatisfactory when a few tweaks to the algorithm would put it on a firmer footing.

Of course, the FIM, SCTA, AMA (and others?) do it differently, but that’s a different discussion. 

As Mayoman says, this is fun.  However, I am aware that not many people agree, so please say if you think we should terminate this discussion.

[kiwi belly tank]

The whole point of a forum is for people to discuss their interest's. If somebody else has no interest in a certain subject, then all they need to do is not read it. Slim will take care of censorship if the need arises.
  Sid.

[WOODY@DDLLC]

Maybe the FIA should flip a coin to determine whether this discussion is rounded off or truncated? 

[TrickyDicky]

The whole point of a forum is for people to discuss their interest's. If somebody else has no interest in a certain subject, then all they need to do is not read it. Slim will take care of censorship if the need arises.
  Sid.

Ah, the wisdom of a 162-year old. Thank you.

I don't post very often, but have been reading here for long enough to know that it's easy to stir some people's negative emotions.  All I need say is "Propster" .........

[Malcolm UK]

In an earlier posting TrickyDicky you mentioned the use of 1% improvement for the necessary approval of a class record set over a particular measured distance and starting method.

When there was this 1% requirement, it was applied to the various world records for each of the distances, even though groups, classes, capacities or weights are not taken into account.

Look at the FIA standing start 1 mile 'world' record (BMW, Hydrogen car) and then at the slightly faster 1 mile standing start record in the FIA nornally aspirated 250cc class.

Nothing has been changed, even though the "1% improvement rule" has now been removed from Appendix D.

[A British driver is not being acknowledged for his performance being the 'best in the world'].

Malcolm, Derby, England.

PS I have always taken 'rounding off' as being the same as 'rounding', but I cannot read the french either. You just write down the three figures after the decimal point.   

[rouse]

I got  truncated once and it didn't fill good.

No matter how you figure it, if the answer is you've set a record it's good. if not run again. Change things up if required.

If someone ran within a hundredth, or a thousandth slower than you did, but 10 years sooner, maybe the math don't matter, you should just make a faster run and settle the difference.

Rouse

[TrickyDicky]

In an earlier posting TrickyDicky you mentioned the use of 1% improvement for the necessary approval of a class record set over a particular measured distance and starting method.

  Ooooh.  Light bulb moment - I see what you have done there.  When comparing classes prior to 2012, you had to stick with the same measured distance when applying the 1% rule.

I was confused by Richard Noble / Thrust II.

In the Thrust Class, Richard set the FS mile record at 633.468 mph which beat The Blue Flame's 622.407 mph by more than 1%.  He also set an officially-recorded FS kilometre speed of 634.051 mph which beat The Blue Flame's 630.478 mph but by less than 1%.  Therefore Thrust II set the overall / world / ignoring class distinctions / whatever is the correct term FS mile record but not the FS kilometre record.

Then to work out the absolute record you compare the mile and kilometre records but without applying the 1% factor because you are not comparing the same measured distance.  Thus 633.468 mph beats 630.478 mph and Richard Noble was the Fastest Man In The World in 1983.

Simple, really. 

Also explains why Mayoman keeps reminding us that The Blue Flame's kilometre record was not beaten until 1997.

[TrickyDicky]

...

PS I have always taken 'rounding off' as being the same as 'rounding', but I cannot read the french either. You just write down the three figures after the decimal point.   

By writing down the three figures after the decimal point, you are 'rounding down' (in my view).  So when the FIA says "with no rounding off", what they must mean is you always 'round down' and never 'round up'.  So 'rounding off' must be the same as 'rounding up'.

My objection to this approach is that it is not consistent when applied to times and speeds; neither is it logical.  Rounding down a time increases the speed calculated from that time, whereas rounding down a speed (obviously) reduces the speed.  There is no reason why the two adjustments should cancel each other out.

If the above explanation is unclear, I can construct a simple example that might show better what I mean.

[PorkPie]

Tricky,

this I tried to say in my reply #10.....

Today stand - due to the split into rocket and jet (why this....?) - the Blue Flame got both records back (and is still a record holder) and the Thrust II lost his record to the Thrust SSC....and the Thrust SSC is the one who holds now the outright (absolute) record....the fastest vehicle on four or more wheels....the former record holder Thunderbolt had 8 wheels.....

In an earlier posting TrickyDicky you mentioned the use of 1% improvement for the necessary approval of a class record set over a particular measured distance and starting method.

  Ooooh.  Light bulb moment - I see what you have done there.  When comparing classes prior to 2012, you had to stick with the same measured distance when applying the 1% rule.

I was confused by Richard Noble / Thrust II.

In the Thrust Class, Richard set the FS mile record at 633.468 mph which beat The Blue Flame's 622.407 mph by more than 1%.  He also set an officially-recorded FS kilometre speed of 634.051 mph which beat The Blue Flame's 630.478 mph but by less than 1%.  Therefore Thrust II set the overall / world / ignoring class distinctions / whatever is the correct term FS mile record but not the FS kilometre record.

Then to work out the absolute record you compare the mile and kilometre records but without applying the 1% factor because you are not comparing the same measured distance.  Thus 633.468 mph beats 630.478 mph and Richard Noble was the Fastest Man In The World in 1983.

Simple, really. 

Also explains why Mayoman keeps reminding us that The Blue Flame's kilometre record was not beaten until 1997.

[TrickyDicky]

Tricky,

this I tried to say in my reply #10.....

Sorry Pork. 

Sometimes I don't fully understand something unless I write it down in my own words.

[TrickyDicky]

...

Look at the FIA standing start 1 mile 'world' record (BMW, Hydrogen car) and then at the slightly faster 1 mile standing start record in the FIA nornally aspirated 250cc class.

Nothing has been changed, even though the "1% improvement rule" has now been removed from Appendix D.

[A British driver is not being acknowledged for his performance being the 'best in the world'].

...

Malcolm, I take your point but ...

There is something strange about the FIA 1 mile Standing Start records.  Very few of the classes have a current record holder.  How can this be?  Presuming it's not just incompetent record keeping, there must be a story to be told.

If I could do 1 mile from a standing start at 99 mph I don't think I'd be concerned about it not being recognised as the 'best in the  world', since it would only be in contention due to a quirk of the historical record.  For example, whatever happened to the records set by this bunch of obscure drivers nobody has ever heard of (Stuck 116+mph; Rosemeyer, 134+mph; Caracciola 127+mph) over 75 years ago.  Perhaps we need a campaign to get these reinstated?

[Malcolm UK]

Standing start (SS) mile - World Records.

I am not sure when the SS mile was 'brought back' as an approved distance by the FIA, but you are right that it appears as a 'modern' record, which few have challenged.  On airfields in the UK it is possible to set such records, hence the attempt by Tony Moir with his 250 cc Superkart included it. If the racers had a fully timed standing mile event, with two runs in each direction, completed within 60 minutes, many World records could probably be established (or could be broken).

I have been told by Louise Ann Noeth that the FIA paperwork is not easy to sort through (she spent time filling out some of the American blanks in the record lists in the late nineties), so to get the details of the records you mentioned may be a task for someone in Paris with a fair amount of time on their hands and then getting then reinstated may take an effort from the records commission.

Malcolm, Derby, England