Hello everyone and welcome! The hunt for 300 miles per hour continues and in this video
we're gonna be talking about whether or not the Hennessey Venom f5 will be capable of hitting that magic
300 mile per hour mark now
There's two things we've got to be talking about here first of all does it have enough power to hit that? Based on its
specifications, and then we're also going to get into tires so in order to know does it have enough power
There's three things we need to look at what is the aerodynamic drag on the vehicle at 300 miles per hour?
What's the rolling resistance and what are the drivetrain losses and from that we can see whether or not it's twin-turbo v8 producing
1600+ horsepower is enough to propel this vehicle all the way to 300 miles per hour now some other
specifications the car weighs 2950 lbs or about 1338 kilograms has a coefficient of drag of just
0.33 and it has a frontal area of 1.83 meters
squared the claims here are zero to four hundred to back down to zero km/h in less than 30 seconds. You'll notice
That's faster than the Koenigsegg record which was just set in a top speed of 301 miles per hour
Also higher than the Koenigsegg record of 278/277 miles per hour which was also just set. So starting things off with
Aerodynamic drag in order to calculate how much power you need to overcome drag
This is equal to the force of drag
Multiplied by the velocity at which you're traveling at of course in this case 300 miles per hour now the force of drag is equal
to one-half Rho, the density of air, V squared, velocity, coefficient of drag multiplied by your area
And then all of that multiplied by the velocity you're travelling at. That gives us one half times 1.225
Kilograms per meter cubed, that's the density of air at sea level at 15 degrees Celsius
Multiplied by 134.1 meters per second that cube
That's the velocity we're traveling at so we're taking V. Squared multiplying also by V V cubed
134 meters per second is equivalent to 300 miles per hour multiplying that by
0.33 and then multiplying that by the frontal area 1.83 meters squared
I'm sure all of you are very happy
We're using metric units here for the most part. So this if you do the math comes out to about
892 kilowatts or about 1196.5 horsepower
So that's the amount of power we need just to overcome
Aerodynamic drag and we do have quite a bit left you know about 400 horsepower left over after you take out aerodynamic drag
So moving on to rolling resistance and once again the power required for rolling resistance is going to equal to the force of rolling resistance
Multiplied by the velocity which we're traveling at that force of rolling resistance is equivalent to the coefficient of rolling resistance
Multiplied by the normal force multiplied by velocity so in our case using a conservative 0.015 where the coefficient of rolling resistance
Multiplying that by the mass of the car 1338 kilogram
Multiplied by gravity 9.81 m/s this combined is our normal force and then multiplying that by velocity
134 meters per second or 300 miles per hour and you do the math there and that gives you a total of 26.4 kW
or about 35.4 hp
Now, there's not actually a linear relationship between the power to overcome rolling resistance and the velocity at which you're traveling at like this insinuates
But we'll get more into that later when we start talking about tires so for now we're gonna use this 35.4 hp
Figure add that to 1196.5 and that gives us 1231.9 hp
We do the math divide that by 1600 that gives us about seventy seven percent so what that tells us is
We have twenty three percent
Drivetrain losses which we could accept and still reach three hundred miles per hour
And it's very unlikely you know this car is rear-wheel drive. It's unlikely that it's going to have 23 percent drivetrain losses
It'll probably be
Significantly less than that and as a result it shouldn't have a problem
Reaching three hundred miles per hour from a power standpoint
It should have plenty of reserve power in order to hit that target mark
But the tires on the other hand will be a challenge and the reason being is because tires get very hot especially
At these really high speeds and so if the tires exceed their
vulcanization temperature about 177°C or about 350 degrees Fahrenheit if the tire reaches that temperature
They start to degrade and they start to fail and so this is what you don't want to happen now
35.4 horsepowers, what's going into that tire and that is a lot by itself?
But actually what happens is as you get above
100 km/h about 100 km/h this equation isn't entirely accurate
Your coefficient of rolling resistance is going to start increasing and so it'll increase exponentially as you get into those higher speeds
Now this is because of aerodynamic drag which of course increases with the square of speed as we learned from our earlier equation
And it's also because of the vibrations that occur at high speeds so that tire is now rotating at a faster speed
It deforms it more those deformations cause it to you know generate more heat
So there's really two things that you want in a tire that are gonna be going in this super fast speed you
Need a low hysteresis, which means a low rolling resistance not much heat that goes into not much waste heat in that tire
But you also want high grip of course
For a tire that you know that's gonna be on this you know extreme performance car and these two can kind of battle against each
other high grip versus low rolling resistance
You also want a high natural frequency of that tire. You don't want the
Vehicle speed to reach the natural frequency of that tire, or it's gonna start forming waves within the tire
And then the tire is going to start to fail from all the heat that those waves are creating
So you want a light tire and you also want a stiff tire and these two once again battle against each other now
Jalopnik actually wrote a really great article. They did some great research on tires if you're curious
I'll include a link talking more about the tire aspect of it in the video description
But overall from a power standpoint the math does show you know that reasonably, you know this number could be significantly higher
And they would still have plenty of left over power even with drivetrain losses to hit it so from a v8
You know the twin turbo 1600 horsepower plus engine and the low kerb weight. What's really impressive. Honestly
Is that they got their drag coefficient so low and their frontal area so low so in the previous video
I said you know can a car hit 300 miles per hour how much power will it need well
I use the Bugatti Veyron as the example and that turned out to about to be about
1,800 horsepower now that car has more weight it has more frontal area and a higher drag coefficient
And that's why that higher horsepower number is required rather than something like
1600 when you can get that drag coefficient down and the frontal area down, so thank you all for watching!
And if you have any questions or comments feel free to leave them below.