It appears Bugatti has resorted to witchcraft...WTF!!

https://www.topgear.com/car-news/concept/bugatti-bolide-mind-blowing-1824bhp-track-car

# Bugatti Chiron Super Sport 300+ specs

Car type | Coupe |

Curb weight | 1978 kg (4361 lbs) |

Introduced | 2020 |

Origin country | France |

Views | 6.7k |

Submitted by | lafars |

### Powertrain specs

Engine type | quad-turbo W16 |

Displacement | 8.0 l (488 ci) |

Power | 1622 ps (1600 bhp / 1193 kw) @ 7000 rpm |

Power / liter | 203 ps (200 hp) |

Power / weight | 820 ps (809 bhp) / t |

Transmission | 7-speed DCT |

Layout | middle engine, all wheel drive |

### Chiron Super Sport 300+ competition

benedekpuskas 5m ago

"Visit carwow.co.uk to see how much you can save on a Bugatti Chiron 300+"

nats50 1y ago

Here is another site on how to calculate air density or rho under different temperature, pressure and humidity or dew point.

nats50 1y ago

Here is another site on how to calculate air density or rho under different temperature, pressure and humidity or dew point. https://www.brisbanehotairballooning.com.au/calculate-air-density/

nats50 1y ago

And here is a very useful site in getting the air density or density altitude, dyno correction factor, etc... Enjoy! https://wahiduddin.net/calc/index.htm

nats50 1y ago

Here is the formula I now use for determining the coefficient of rolling resistance. The SAE suggested an empirical formula for the rolling resistance in dependence of inflation pressure pi [N/m^2], forward velocity v [m/s] and tire load Fz [N]:

Fr = K/1000(5.1 + 5.5 x 10^5 + 90 Fz/pi + 1100 + 0.0388Fz/pi)v^2 where the factor K is taken as 0.8 for radial tires and as 1 for non-radial tires.

Fr = Rolling resistance

Fz = Tire load in N = newtons

pi = Inflation or tire pressure in N/m^2

v = Velocity or speed in m/s

Cr = Coefficient of rolling resistance (unitless)

m = Mass in kilograms

g = Acceleration due to gravity = 9.80665

Hw = Wheel Horsepower

Af = Frontal area in sq ft

Cd = Coefficient of drag

S = Speed in mph

W = Weight of car and driver in pounds

Fr = Crmg

Hw = 0.0025565AfCdS^3/375 + CrSW/375 -> divide the result by a factor such as 0.80 for 20% power loss, 0.83 for 17%, 0.85 for 15%, 0.87 for 13%, and so on to get the crank or flywheel horsepower needed to attain the top speed. Convert the units as needed.

nats50 1y ago

I've done this revised calculations on the top speed using my own version, with a twist, of known formulas and equations . It can be achieved if it meets these parameters. Of course, there are many possible combinations of frontal area and drag coefficient, not to mention power loss which can only be accurately determined by putting the car on a dyno. There are many formulas or equations on predicting accurately the theoretical top speed--from the simplest to the most complex. As you probably know, there are like 4 forces or resistance acting on a moving car that influence top speed--air resistance; rolling resistance; gradient resistance and inertia. The first two are the most prominent. The gradient is usually not included in the mix cause top speed is supposed to be run on a relatively flat road or track, and that is why two runs, from both directions, are needed to negate any possible slope, uphill and downhill, not to mention wind, and just average the two speeds. Inertia is also neglected or may be insignificant for some reason. Anyway, I've developed my own version and I came up with these results. As I said earlier, there are infinite number of combinations you can do to arrive at the same top speed theoretically. Before I forget, they are based on standard temperature, pressure and humidity of--59 F, 29.92 inHg and 0% humidity--rho at 1.225 kg/m^3 or 0.00237689 slug/ft^3. They all mean the same thing. There are formulas out there on how to determine rho exactly using different temperature, pressure or elevation, and humidity. That is why I use or the constant 0.0025565 is used to simplify. Also, it must be known that there are different types of top speed--gear limited and rev limited (not to be confused with governor or electronically), power or drag limited. Finally, the frequently neglected and "insignificant" rolling resistance seems to be the more problematic one. There are many formulas or equations on how to determine the rolling resistance value. It can be seen that tire pressure, weight and even speed affect rolling resistance and consequently top speed. The air resistance is pretty much straightforward and well known. Again, I came up with these results and here they are:

Hc = Crank or flywheel horsepower

Hw = Wheel horsepower

Af = Frontal area in square feet

Cd = Drag coefficient

Pl = Power loss in percent

Pi = Tire pressure in psi (44 is usually used)

Cr = Coefficient of rolling resistance

W = Curb weight of car plus driver (165 is normally used) in pounds

S = Speed in miles per hour

Bugatti Chiron Super Sport 300+

Hc = 1,600 bhp -> 1622ps

Hw = 1,373 whp (air resistance) + 35 whp (rolling resistance) = 1,408 whp

Af = 22.30 sq ft -> 2.072 sq m

Cd = 0.319

Pl = 12.0%

Pi = 44 psi

Cr = 0.0095

W = 4,526 (4,361 + 165) lbs

S = 304.77 mph

Koenigsegg Agera RS

Hc = 1,144 bhp -> 1,160ps

Hw = 973 whp (air resistance) + 23 whp (rolling resistance) = 996 whp

Af = 20.16 sq ft -> 1.873 sq m

Cd = 0.330

Pl = 12.9%

Pi = 44 psi

Cr = 0.0096

W = 3,243 (3,078 + 165) lbs

S = 277.87 mph

SSC Tuatara

Hc = 1,350 bhp -> 1,369 ps

Hw = 1,030 whp (air resistance) + 31 whp (rolling resistance) = 1,061 whp -> 21.4% power loss -> 0.013 -> 311.00 mph

Hw = 1,070 whp (air resistance) + 32 whp (rolling resistance) = 1,102 whp -> 18.4% power loss -> 0.013 -> 315.00 mph

Hw = 1,122 whp (air resistance) + 40 whp (rolling resistance) = 1,162 whp -> 13.9% power loss -> 0.014 -> 320.00 mph

Af = 18.00 sq ft -> 1.672 sq m

Cd = 0.279

Pl = 21.4%, 18.4%, 13.9%

Pi = 44 psi

Cr = 0.013, 0.013, 0.014

W = 2,915 (2,750 + 165) lbs

S = 311.00 mph, 315.00 mph, 320 mph -> calculated top speed?

nats50 1y ago

https://www.facebook.com/watch/?t=10&v=191073695633737

A simple case of power to weight ratio win by Koenigsegg?

nats50 1y ago

Want to know the approximate wheel horsepower loss at altitude? http://dgm2780.austinbroadhead.com/whpCalculator/

HighGear 1y ago

Source: https://www.topgear.com/car-news/supercars/bugatti-chiron-super-sport-300-production-300mph-car

The power output is 1,578 hp (1,600 PS).

Price: 4.2 Million pounds (5.18 Million US dollars)

Top Speed: 304.77mph*

*https://www.topgear.com/car-news/bugatti-has-broken-300mph-barrier?fpn=1

manone 1y ago

"Why can't it reach 490 kph with 1600 ps? What are those "engineering peeps" that are so convinced it can't? Have they studied the shape of the car?"

Ok, let's do few computations for Veyron SS. The formula relating power to CdA, speed v and air density rho is:

P = CdA * v^3 * rho/2.

Knowing V=431km/h=119.7 m/s, P=1200bhp=895kw and rho@15C=1.225 kg/m^3,

we get a CdA of 0.85.

Therefore, for the Veyron SS to reach 490km/h you need 1307kw=1753bhp for

overcoming the drag alone from 431kmh to 490kmh. Then you have to add:

Back to the Chiron SS: the A factor of Cd*A is seemingly not less than the

Veyron SS's. How much they could have decreased the Cd from the Veyron SS to the Chiron SS, provided the extra front venting surfaces the latter has?

lafars 1y ago

very informative video regarding this car:

https://www.youtube.com/watch?v=DFlUYWfwOUg

FastestLaps 1y ago

You know what is the saddest part - we still don't have proper data for the original Chiron :D

Bugatti are basically pulling a Christian von Koenigsegg.