Things you always wanted to know the answer to [Vol. 5]
Discussion
Grey_Area said:
captain_cynic said:
119 said:
Aerodynamics would probably be a huge factor.
And gearing?
Friction and weight as well.And gearing?
Air gets thicker as you get faster, which increases drag.
Love this stuff!
Clockwork Cupcake said:
That was actually a long-time poster who got bored with PH and, I think, decided to see how much of a tiresome arse he could be before he was banned. 
Nonsequiter? I, for one, usually laughed at his puns rather than worked myself into a murderous rage, but horses for courses.
dave123456 said:
My speedometer reads 83mph at 2000rpm in my highest gear.
The engine redlines at 6500rpm.
So a theoretical top speed of 270mph.
What factors contribute, in what order, to the failure to achieve this?
C Class estate. 385ish bhp. Let’s assume an indefinite length, flat road, 155mph limiter removed.
The short answer is aerodynamic drag. At 300 km/h the force from drag is about 25 times larger than friction, tyre rolling resistance etc combined The engine redlines at 6500rpm.
So a theoretical top speed of 270mph.
What factors contribute, in what order, to the failure to achieve this?
C Class estate. 385ish bhp. Let’s assume an indefinite length, flat road, 155mph limiter removed.
deadtom said:
dave123456 said:
My speedometer reads 83mph at 2000rpm in my highest gear.
The engine redlines at 6500rpm.
So a theoretical top speed of 270mph.
What factors contribute, in what order, to the failure to achieve this?
C Class estate. 385ish bhp. Let’s assume an indefinite length, flat road, 155mph limiter removed.
The short answer is aerodynamic drag. At 300 km/h the force from drag is about 25 times larger than friction, tyre rolling resistance etc combined The engine redlines at 6500rpm.
So a theoretical top speed of 270mph.
What factors contribute, in what order, to the failure to achieve this?
C Class estate. 385ish bhp. Let’s assume an indefinite length, flat road, 155mph limiter removed.
Clockwork Cupcake said:
deadtom said:
dave123456 said:
My speedometer reads 83mph at 2000rpm in my highest gear.
The engine redlines at 6500rpm.
So a theoretical top speed of 270mph.
What factors contribute, in what order, to the failure to achieve this?
C Class estate. 385ish bhp. Let’s assume an indefinite length, flat road, 155mph limiter removed.
The short answer is aerodynamic drag. At 300 km/h the force from drag is about 25 times larger than friction, tyre rolling resistance etc combined The engine redlines at 6500rpm.
So a theoretical top speed of 270mph.
What factors contribute, in what order, to the failure to achieve this?
C Class estate. 385ish bhp. Let’s assume an indefinite length, flat road, 155mph limiter removed.
deadtom said:
Clockwork Cupcake said:
That was actually a long-time poster who got bored with PH and, I think, decided to see how much of a tiresome arse he could be before he was banned.
Nonsequiter? I, for one, usually laughed at his puns rather than worked myself into a murderous rage, but horses for courses.
I'm just observing that after a while it felt deliberate rather than organic. Also he stopped doing normal non-joke posts (which I used to find interesting and informative, and missed seeing)
Anyway, water under the bridge and I only mentioned it in response to what popeywhite said.
Rusty Old-Banger said:
What about on a conveyor belt? Seriously - the car isn't moving through the air so no air resistance...
Different inertial frame of reference. The speed of the car is zero with respect to the air. It only has speed relative to the conveyor belt, and even then that is just wheel speed. If you asked the average person "How fast is this car going?", most people would look at it and reply "It's not moving at all but its wheels are spinning quite fast". But let's not go there on the conveyor belt again, eh?
Edited by Clockwork Cupcake on Tuesday 2nd April 12:59
Clockwork Cupcake said:
Rusty Old-Banger said:
What about on a conveyor belt? Seriously - the car isn't moving through the air so no air resistance...
Different inertial frame of reference. The speed of the car is zero with respect to the air. It only has speed relative to the conveyor belt, and even then that is just wheel speed. If you asked the average person "How fast is this car going?", most people would look at it and reply "It's not moving at all but its wheels are spinning quite fast". But let's not go there on the conveyor belt again, eh?
Edited by Clockwork Cupcake on Tuesday 2nd April 12:59
I did think twice about mentioning it. But then did it anyway
Clockwork Cupcake said:
Also air resistance is a square law. So if you double your speed you get four times the amount of air resistance (drag).
Yes aerodynamic drag (which is a force) has a square law, but since the power required is drag x velocity, the power required has a (speed) cubed law.119 said:
Grey_Area said:
captain_cynic said:
119 said:
Aerodynamics would probably be a huge factor.
And gearing?
Friction and weight as well.And gearing?
Air gets thicker as you get faster, which increases drag.
Love this stuff!
StevieBee said:
Some years back the Honda / BAR F1 team attempted (and IIRC) succeeded in breaking the land-speed record for a wheel-driven car (as apposed to the jet-propelled cars), using an adapted F1 car. The principle change was to aero, removing the wings but retaining just enough 'ground-effect' to keep it planted. They maxed out at something like 420 kph. The factors limiting more were the tyres that have a rotational speed limit before they break apart, and the length of the desert they had to play with (11 miles). They reported that car continued to accelerate but the rate of acceleration decreased the faster it got.
Are you sure? The final official World Land Speed record for a wheel-driven car was 648.73 kph (403.10 mph) by Donald Campell in 1964 and the record currently stands at 745.187 kph (463.038 mph) which was set in 2018Sources:
https://en.wikipedia.org/wiki/Land_speed_record
https://en.wikipedia.org/wiki/List_of_vehicle_spee...
Mind you, given BAR were basically Red Bull in all but name I wouldn't put it past them to claim it anyway.
Edited by Clockwork Cupcake on Tuesday 2nd April 19:44
Nethybridge said:
StevieBee said:
They reported that car continued to accelerate but the rate of acceleration decreased the faster it got.
So it stopped getting faster ? Surely you have experienced the "pushing you back in your seat" feeling dropping off whilst accelerating and the needle on your speedo continuing to climb but more slowly?
Stop trying to be clever and actually be clever.
Edited by Clockwork Cupcake on Tuesday 2nd April 20:50
Clockwork Cupcake said:
StevieBee said:
Some years back the Honda / BAR F1 team attempted (and IIRC) succeeded in breaking the land-speed record for a wheel-driven car (as apposed to the jet-propelled cars), using an adapted F1 car. The principle change was to aero, removing the wings but retaining just enough 'ground-effect' to keep it planted. They maxed out at something like 420 kph. The factors limiting more were the tyres that have a rotational speed limit before they break apart, and the length of the desert they had to play with (11 miles). They reported that car continued to accelerate but the rate of acceleration decreased the faster it got.
Are you sure? The final official World Land Speed record for a wheel-driven car was 648.73 kph (403.10 mph) by Donald Campell in 1964 and the record currently stands at 745.187 kph (463.038 mph) which was set in 2018Sources:
https://en.wikipedia.org/wiki/Land_speed_record
https://en.wikipedia.org/wiki/List_of_vehicle_spee...
Mind you, given BAR were basically Red Bull in all but name I wouldn't put it past them to claim it anyway.
Edited by Clockwork Cupcake on Tuesday 2nd April 19:44
F1 nerd incoming alert......
BAR became Honda which became Brawn which became Mercedes. Pre BAR they were Tyrell.
Red Bull Started life as Stewart GP, then Ford (under the Jaguar brand) before Red Bull hoovered them up.
StevieBee said:
Was trying to maintain the spirit of the thread and not consult Google, but yeah - nowhere near the record. Still rapid though.
F1 nerd incoming alert......
BAR became Honda which became Brawn which became Mercedes. Pre BAR they were Tyrell.
Red Bull Started life as Stewart GP, then Ford (under the Jaguar brand) before Red Bull hoovered them up.
Oh! I must have got myself muddled up there. I had it in my mind that BAR became Red Bull. Certainly I thought that Christian Horner had some kind of involvement with BAR anyway. I will have to go look it up now!F1 nerd incoming alert......
BAR became Honda which became Brawn which became Mercedes. Pre BAR they were Tyrell.
Red Bull Started life as Stewart GP, then Ford (under the Jaguar brand) before Red Bull hoovered them up.
Yes, the evolution of the various names of the various teams is fascinating isn't it!
(edit: And, yes, you were completely correct on the history of both teams. I just got myself muddled up)
Edited by Clockwork Cupcake on Tuesday 2nd April 21:18
StevieBee said:
Some years back the Honda / BAR F1 team attempted (and IIRC) succeeded in breaking the land-speed record for a wheel-driven car (as apposed to the jet-propelled cars), using an adapted F1 car. The principle change was to aero, removing the wings but retaining just enough 'ground-effect' to keep it planted. They maxed out at something like 420 kph. The factors limiting more were the tyres that have a rotational speed limit before they break apart, and the length of the desert they had to play with (11 miles). They reported that car continued to accelerate but the rate of acceleration decreased the faster it got.
The remit was to break 400kph in a legal F1 car. Gassing Station | The Lounge | Top of Page | What's New | My Stuff