The dude over at engineering explained goes in to depth on the recording setting car. One thing that puzzles me about record setting electric cars he does not explain. In general a gas car needs 1000 horsepower to hit 200 mph but an electric car needs 2000 horsepower. The only thing I can think of is the power is not being delivered to the wheels due to a lack of gearing. I’m also surprised he did not calculate the terminal velocity of the car. A car approaches the terminal velocity according to the hyperbolic tangent. What you need is data on speed at time toward the end of the run. I might tackle the problem if I had the data. The problem is the spastic photographers who make these videos keep cutting back and forth between the speedometer the view out the window and the drone shots. Also I would like to have a curve fitting program to save a lot of work. Clearly the car was still accelerating at 300 mph. A lot of people have died when their tires exploded so I don’t blame the driver for backing off. https://www.youtube.com/watch?v=z6q7du1q2U8
I think the numbers needed to hit 200mph is off. The ferrari f40 did it with less than 500hp almost 40 years ago
Given a very long launch road, like the salt flats, surely a low torque high speed engine, with an assisting start motor, as well as very streamlined aerodynamics could hit 200mph using less than 500hp…theoretically, anyway. Also hypothetically, is microturbulence actually beneficial for aerodynamics?
This micro turbulence is one of the (yet: grey) area’s of propulsion in water. I don’t have the backup data ready but:
The were experiments with lining the hul (of a sub) with a substance that looks/feels like shark skin. Stating that the micro turbulence would cause less drag than a clean hard metal surface.
UCLA has done research on micro turbulence by means of microscopic air pockets https://samueli.ucla.edu/drag-reduction-technology-for-boats/
There is reasearch on blowing air bubbles out of certain area’s of the hull to reduce drag https://boattest.com/article/air-lubrication-hull-bottoms-can-reduce-drag
And of course there is an example I can’t find back on the web, but there was a ship built that already uses such techniques (Mitsubishi?).
My opinion: if it’s feasable in water (very thick moist air), something similar could be done with air. We just have to sind the yet unknown but maybe very simple trick that fixes things. Like the fan-jet, the area-rule, to name a few.
At over (ca) 60 mph the mayor factor of restricting a car to go faster is drag. But there are cars and there are cars. Drag depends on how much air the car needs to push aside (area) en how much (relative) effort to do so (drag coefficient). Product of the two is drag area.
You are quite right: a car that is small and sleek (F40) needs less power to attain certain speeds. A bigger car needs more power to do the same speed. And if you want to go faster you need even more power. Like throw it is to the 2nd power. Twice the throw = four times lumens. Twice the speed = four times the power. Bigger car AND more speed: do the math.
Personally I think 2,000hp is a bit overkill for 300mph, but that’s just math. Because: where will you find a “street” long enough, without traffic lights, to make that possible. And last but no least: I think that with 2,000hp you need a re-charge and a new set of tyres in about 10 to 15 minutes.
golf ball dimples!
Fastest car on ice.
My one experience with a car on a frozen lake with a pretty smooth ice surface was much different. When I say pretty smooth I mean it was good enough to ice skate on. There was no snow at all.
71 Ford mustang. V8, solid rear axle with an open differential, Firestone Town and Country studded mud and snow tires, bias ply, they were nearly bald and had about one or two studs per tire left.
Max speed was as I recall somewhere between 33 and 35 mph. I figured I must have been driving into a headwind. Got to the other side/ end, turned around and headed back, same thing. Constantly on the edge of spinning one rear tire just to get moving and gain speed I could eventually get up to that 33 to 35 mph. That was it. No matter how you played with the gas pedal trying to go any faster just resulted in one tire spinning. The air resistance at that speed was greater than the friction/ traction the bald rear tires could provide.
I did have the windows open. Let’s just say, in case. Most of the ice was 17 inches thick but there was some open water in some places.
So I spent the next hour just getting up to max speed and then throwing it into spins to see how many I could get. I did the same thing the next day for an hour with the same result.
When I first met my wife I had a 2001.5 VW Passat 4motion v6. I had her in the passenger seat and a guy in the back. Drove off the boat launch and brought it up to 40-45, cut the wheel and floored it. The guy in the back seat was loosing it lol. Needless to say, I did not know at that time my at the time girlfriend was not OK with that, at all… lol. I cant goof off driving at all with her in the car, but luckily my daughter loves when it snows and I can hit a lot and do some doughnuts
I grew up spending a lot of time on frozen lakes. Learned to drive a manual at like 7-8 years old in a mid 80s s10 blazer. There was a go kart track plowed on the lake, so he was teaching me to drive manual and sliding at the same time lol. Hit the banks several times
This talk of aerodynamics reminds me of a game a roommate and myself would sometimes play. We called it “Air Brakes”.
He had a late 1970s Volkswagen rabbit two-door with 70 hp.
We would be driving along at about 40 mph and the driver or passenger would just randomly yell “air brakes”.
Both would open the door and use their foot to push the door wide open. This is with the windows up. I seem to recall those doors were pretty long and they opened very wide.
That would knock the speed down to 30 mph in just a few seconds. Most of the time you would take your foot off the gas pedal. But we tried it a few times by holding the gas pedal steady and it would still knock almost 10 miles an hour off very quickly.
I don’t think we ever tried it above 45 mph. It took a lot of leg Force at 40 to 45 miles an hour to push those doors fully open.
According to the math I learned from cycling science the Bugatti Veyron needs 1683 horsepower to hit 300mph. That car has 11 radiators and is an aerodynamic nightmare. The Chinese car certainly has a lower coefficient of drag. Insurance companies don’t like high horsepower. I remember in the 70’s people were paying $20 per mile insurance for a car that could do 180. My sister is the market for a car. I need to keep her happy since she handles my mail when I bicycle tour.
Exactly.
The dimpling would have to be differential; because a golf ball is round, all the dimples can essentially be the same depth, pitch, or whatever. With a car, the aerodynamics would be a bit different…less hemispherical dimples and shallower relative to the curve