I never realised that about Sumeria and the base 60 we still use today!godlameroso wrote: ↑13 Mar 2018, 00:15South American people are very familiar with metric, but there's also nothing wrong with Sumerian 12.johnny comelately wrote: ↑13 Mar 2018, 00:06Thank you for that, it verifies the timesgodlameroso wrote: ↑12 Mar 2018, 22:27
~8.5 seconds for the 400m
PS Sochi has a very nice run up to turn 2, way over 400m.
In Bahrain the run from the starting line to the speed trap is exactly 400 m Bottas did a 8.6 @ 155 mph or 250kph, but his 60' is terrible almost 2 seconds.
when did Miami go metric ?
The 60 foot time is a shocker.
Is the car weight right?Mudflap wrote: ↑13 Mar 2018, 01:56I had a go at calculating power from onboard acceleration - more of a proof of concept rather than an attempt to work out exact power.
I started off with Seb's Singapore pole lap from last year (https://www.youtube.com/watch?v=xPXfr3f0veI) and used http://www.watchframebyframe.com to extract engine and car speed versus time. Interestingly this website would not work for official F1 videos (apparently FIA is not happy with people analyzing on board videos frame by frame). Only the first straight was analyzed as I can't be arsed to through the whole lap frame by frame.
Unfortunately the video is only 25 FPS so the resolution (as in sampling frequency) is very poor (and so is that digital speedo), as a result I had to skip ahead frames until engine speed changed, which means that the time interval is not constant and samples are shite. Normally you'd probably need good data every hundreth of a second to be able to come up with reasonable numbers.
From speed vs time I calculated acceleration and then inertia load assuming a car mass of 628 kg.
Gear ratio was calculated from engine speed vs car speed (wheel radius =335 mm). I got a ratio of 5.84 for the 6th gear, 5.16 for the 7th and 4.55 for the 8th gear. These are pretty close to ratios calculated here forum/viewtopic.php?f=4&t=26230.
Drag was calculated using the average car speed over the time interval. (Cd=1 and frontal area of 1.442 m^2, someone posted these a while ago).
Wheel torque was then calculated by multiplying the sum of drag and inertia loads by the wheel radius. Dividing wheel torque by gear ratio gives engine torque. Multiplying by engine speed gave engine power. No transmission losses nor rolling resistance considered.
https://i.imgur.com/eYoniGM.png
https://i.imgur.com/mEGtFTd.png
https://i.imgur.com/5pP7wJ1.png
https://i.imgur.com/BOJNcH1.png
Greyed out rows mean funny data due to gearshifts. Last data point is also dodgy - I think it includes braking at end of straight.
It's car mass. Weight is technically mass x g and has units of newtons.johnny comelately wrote: ↑13 Mar 2018, 02:00Is the car weight right?
Very detailed, lot of effort, was it a Freudian slip with "arsed"?
Yes OK, but you have it as Kg and I was just wondering if it is right with FIA minimum being 733kg dry +driver (no fatty la la's) +105kg fuel ??Mudflap wrote: ↑13 Mar 2018, 02:07It's car mass. Weight is technically mass x g and has units of newtons.johnny comelately wrote: ↑13 Mar 2018, 02:00Is the car weight right?
Very detailed, lot of effort, was it a Freudian slip with "arsed"?
See, I'm always anal lol.
Everything, thats where all this started.
It's pointless to look at launch since the car is traction limited for most of it. It won't tell you anything at all.johnny comelately wrote: ↑13 Mar 2018, 02:24Everything, thats where all this started.
seeing how lean they were and produced X power without knocking and destruction and how they do it.
The weight is was looking at was start weight and I was using that for launch calcs.
whereas yours is during the race, lap ??
Mudflap, have a quick look at "henry"'s posts on page 600Mudflap wrote: ↑13 Mar 2018, 02:28It's pointless to look at launch since the car is traction limited for most of it. It won't tell you anything at all.johnny comelately wrote: ↑13 Mar 2018, 02:24Everything, thats where all this started.
seeing how lean they were and produced X power without knocking and destruction and how they do it.
The weight is was looking at was start weight and I was using that for launch calcs.
whereas yours is during the race, lap ??
So, the lowest non-grey hp figures are about it 640 to 670 hp (without electric shove) ??Mudflap wrote: ↑13 Mar 2018, 01:56I had a go at calculating power from onboard acceleration - more of a proof of concept rather than an attempt to work out exact power.
I started off with Seb's Singapore pole lap from last year (https://www.youtube.com/watch?v=xPXfr3f0veI) and used http://www.watchframebyframe.com to extract engine and car speed versus time. Interestingly this website would not work for official F1 videos (apparently FIA is not happy with people analyzing on board videos frame by frame). Only the first straight was analyzed as I can't be arsed to go through the whole lap frame by frame.
Unfortunately the video is only 25 FPS so the resolution (as in sampling frequency) is very poor (and so is that digital speedo), as a result I had to skip ahead frames until engine speed changed, which means that the time interval is not constant and samples are shite. Normally you'd probably need good data every hundreth of a second to be able to come up with reasonable numbers.
From speed vs time I calculated acceleration and then inertia load assuming a car mass of 628 kg.
Gear ratio was calculated from engine speed vs car speed (wheel radius =335 mm). I got a ratio of 5.84 for the 6th gear, 5.16 for the 7th and 4.55 for the 8th gear. These are pretty close to ratios calculated here forum/viewtopic.php?f=4&t=26230.
Drag was calculated using the average car speed over the time interval. (Cd=1 and frontal area of 1.442 m^2, someone posted these a while ago).
Wheel torque was then calculated by multiplying the sum of drag and inertia loads by the wheel radius. Dividing wheel torque by gear ratio gives engine torque. Multiplying by engine speed gave engine power. No transmission losses nor rolling resistance considered.
https://i.imgur.com/eYoniGM.png
https://i.imgur.com/mEGtFTd.png
https://i.imgur.com/5pP7wJ1.png
https://i.imgur.com/BOJNcH1.png
Greyed out rows mean funny data due to gearshifts. Last data point is also dodgy - I think it includes braking at end of straight.
re Henry page 600: FIA traction rules.
I know you do not agree with using ET for power calcs but i am looking for corroboration with other methods to determine power , align that with fuel and voila: lambda.johnny comelately wrote: ↑13 Mar 2018, 12:35re Henry page 600: FIA traction rules.
and keeping it in context, launch is a launch is a launch the idea being to get away the quickest possible; so no electric shove just horsepower and optimised tyre spin and FIA weight distribution it is giving me an indicative power.
With your figures adjusted by a bit for extra 180 kg (640 - 670hp) of mass weight (by the time honoured method of that looks about right ) it is looking around 760 to 800 hp ; what do you think?
I think you can't understand very simple things that have already been explained to you several times.johnny comelately wrote: ↑13 Mar 2018, 12:35re Henry page 600: FIA traction rules.
and keeping it in context, launch is a launch is a launch the idea being to get away the quickest possible; so no electric shove just horsepower and optimised tyre spin and FIA weight distribution it is giving me an indicative power.
With your figures adjusted by a bit for extra 180 kg (640 - 670hp) of mass weight (by the time honoured method of that looks about right ) it is looking around 760 to 800 hp ; what do you think?