According to my calculations, for my first car to have an R factor that meets the practice test results (which shows the actual consumption per lap) I need an R factor of .48 for a 1.1% difference between estimate and actual results.
Maybe you just built a good car, at this point Iām about as clueless as you on the r valuesā¦ unless that car has a turbo?
Ehh, Iām just gonna call it a good car. 
[quote=āPackbat, post:642, topic:6706ā]
Thatās about right - the median car should go about 17% further than r = 0.75 would predict. Itās an intentionally conservative estimate.
(That is, assuming that Hockenheimring is exactly the same as Norisring, which it isnāt.)
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How r varies with design is ā¦ subtle. I donāt understand it. I think having a lot of power below peak power and having gear ratios which are narrow relative to the width of the power band helps - revving to and above peak power tends to increase fuel consumption.
Having excess power relative to tyre grip may also reduce consumption just because you spend less time at full power.
To me, the amount of time spend in full throttle depends solely on the track layout. (Not to say that the car doesnāt affect it, but it should be close to meaningless and an unnecessary degree of complication)
From my many years of watching f1, I learnt that Monza, which is pretty much 4 straights with chicanes in between and the fastest track in f1, has a full throttle ratio of about 65-70%. I would call it the upper limit for non-ovals.
Meanwhile, monaco and singapore are both very tight, technical street circuits, the tightest possible. And those have about 40% of full throttle times.
Using some common sense, it should be easy to get a good ballpark judging by the track layout. For hockenhein in this old layout, I would say it is about 60-65% of the lap under full throttle, and that is the number I used in my own calcs, and they turned out accurate enough.
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I have become packbat, sperger of automation.
edit by Der Bayer: made an external link to Google Docs because it broke the thread for Firefox users.
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WTF is wrong with this tread??? When i try to read past post 666, i get to todays posts, then it connects to Google docā¦ and iām back at post 666ā¦???
Edit: I had to disconnect fron the internet to be able to read all posts, as soon as i connected to make this edit,
BAM!!! back to posts from 5 days ago (post 666).
Using firefox, right? Some stuff just doesnāt work properly.
Happens to me all the time on discourse.
Very interesting, I need to look at my calculations again as I had TheBobWiley being significantly faster (lower total track time) than TheBobWiley2 based on pits, pit time, etc. I need to get my strat turned in before I forget :\
My calculations had my cars in a different order too, looking at the data it seems my first car has registered 10 lap times but is listed as only having completed 9 laps, which would definitely skew the time somewhat going on the formula used. Not entirely sure why thatās happened I must admit.
Thanks for sharing Riso, itāll be interesting to compare the two leader boards after the race.
The data seems off, will try to look it over at some point, but this is Finals week :
My first car (placed 5th in testing) is listed as 26th based on total track timeā¦ unless total track time does not necessarily equate to finishing positions.
Itās always possible the calculations are junk but if you look at the data you will see tyre degradation is a huge factor. For simplicity I assumed all people will pit at about 30% tyre degradation like the default in the tool suggests.
TheBobWiley, after 17/18 laps in practice your lap time was 13.05/12.52 seconds worse than on new fresh tyres because you managed to get 31.4/33.02% tyre degradation.
As a result you are actually quite slow and have to pit nine times.
Edit: mattmr2 according to the data your first car can only hold enough fuel for nine full laps. Your engine reliability is also crap so your chance to finish is about zero.
@Riso: Much appreciated! May be fun to have as reference during race commentating, too - starting point from which we can see where things differ.
(Docs embed was unusable on mobile Safari too - thanks for the fix, @Der_Bayer!)
I know, but I didnāt realise how cooling affected reliability until after the deadline, so my revised/more reliable cars canāt be entered. Costly mistake.
I think the non-integer number of pit stops and laps/pit in the data might be throwing things out a bit, calculations definitely arenāt junk though.
Thanks for the stats, always really interesting to compare. Iām just happy this isnāt the proper BRC76 as I would be properly screwed at that. Still some fudge factors like weather, crashes and strats that will alter this, but will be a great document to do comparisons 
Iām I correct to assume tires will be changed every pit stop?
If you selected Endurance when setting up your pit strategy, I assume it is.
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Can confirm Packbat commentating?
Also, yeah, I can see that my fuel use is too low, as I need to pit for tyres I donāt really gain from it. Damn.
All of the learnings.
Exactly my problem. Iām loosing 6sec per lap when my tank is emptyā¦
I updated the sheet to round down to the nearest full integer. Results changed a bit as I had to calculate a new final stint. Itās still a bit off because thereās some people who pit at the penultimate lap!
I congratulate rcracer11m for his inevitable victory 
Woo first BRC competition and its looking good so far.