To calculate the power of the engine, a parameter referred to as horsepower. Each person close to the car themes knows that in the vehicle documents, this parameter is defined. However, not always power is determined by horsepower. So, the power of the motor can be measured in kilowatts per hour. To obtain accurate calculations, you will need something to know.
Next:
- vehicle;
- station then.
For a clear understanding of the car engine measurement process, the consecutive algorithm of steps is given below, allowing the process of interest to the process as quickly as possible.
Procedure:
Interesting to know! In 1789, in Scotland, James Watt was the first to apply the concept of "horsepower" to determine the power of the car engine.
So, using the knowledge gained in high school in the lessons of mathematics, as well as spending some time, you can define an important parameter of your vehicle - engine power.
Previously, the trees were more, and the sun brighter, and the cars pulled better - remember, 20 years ago 115 hp It was enough for the heart to go to the heels, and the car is for the horizon. Now other times and 200-strong motors do not impress the impressions of powerful. "Does not pull" - the owner of the new car crushes. And he doesn't mind that it is not in power and not in volume - but perhaps the fact that the numbers on paper do not correspond to real indicators. It is written - 100 horsepower, and in reality - less than 100. It is written that overclocking is 9 seconds from the place to "hundreds", but in fact more than 13. How can it be? Now we will tell.
At first there were rumors: on car forums periodically slipped information that in individual brands, and more precisely - in specific manufacturers, the motor power does not always correspond to the stated indicators. Then there were facts: contacting the specialists, we got a clear answer: Yes, such facts take place. Naturally, we decided to figure out or confirm, or refute this information.
Well, then the intrigue began: immediately several dealers, having learned why we take the car, at the last moment they refused to provide it. I had to go for a trick: instead of those brands that rumors run, we took their "clones", with the same motors. And sent to the power metering stand. If you think, you can guess what brands are we talking about if "clones" were played by Skoda and Kia.
Skoda Rapid is equipped with a "volophilixwage" motor that can be found on machines of different brands 
Rio "in the database" is equipped with a very powerful engine: among the "state employees" 123 liters. p. Discontinued with volume 1.6 are almost a record We sing brave madness, we sing: Skoda and Kia dealers understood what they walked. We realized that the consequences could be given to the fact that in the MOTOR MOTOR, which was still running a car, lacking a couple of three, and then a dozen "horses". But cars provided without any conditions. And waited - with the phone in one hand and with Validol to another.
For measurements, we went to one of the oldest and authoritative companies in Belarus. Her owner, Andrei Batchko, is well known in the Belarusian motor racing, especially in the rally. And through his dinostites, almost all powerful cars in the republic went through - both serial and created for motor racing. The inertial dynamometric stand Dynavtech allows measurements on vehicles with any type of drive - front, rear, complete, high-speed range up to 260 km / h.
The process of measurement occurs: the car exposes on inertial drums, and is fixed in front and rear belts. Two powerful fans are summed up to the radiator grille to provide the necessary air flow. Next, the motor starts, and begins to spin the drums to the maximum speed, which is achieved on the penultimate, direct transmission. The drums have a certain inertia - it is according to how quickly the engine will be able to unwind them up to a certain speed, its real torque is determined. And after overclocking to the maximum, neutral turns on, and it is measured by the elevation - by how long the drums will rotate the drive wheels with their inertia, transmission losses are determined. Following the tests, both parameters are compared with a special program, and the engine power "on the flywheel" is calculated - that is, those data that all automakers indicate technical data.
Skoda Rapid with a 110-strong gasoline engine and a 5-speed manual transmission drives onto the stand on the stand. The air conditioner is turned off, ESP - also, the engine is warm to the operating temperature, on the street - 20 degrees Celsius. Forward.
Although Rapid does not sound threateningly, like a supercar, in the course of the measurement I want to move away and sideways. The front wheels are bright rotate the drums, the tires are already squeezed from the speed, the vehicle is pulled by belts twisted, as if it tries to break down, and the speed on the scoreboard grows unnaturally quickly: up to 200 km / h Rapid accelerates so quickly, as if it is Ferrari. But in fact, this is an illusion: in real conditions, the machine will accelerate much longer due to the aerodynamic resistance to such speeds.
"Good eager, Skoda, most likely, there will be very small transmission losses - comments Andrei - well, plus the tires are clearly with a little rolling resistance."
So, what did the manufacturer promised there? Four-cylinder atmospheric engine with a working volume of 1598 cm. Cube. Must develop the capacity of at least 110 liters. with. At 5800 rpm, the maximum torque of 155 Newton meters is achieved at 3800 rpm. And what in fact?
The tests showed that the engine power was even slightly higher than the stated - 111.6 liters. with. at 5701 rpm. But the peak of torque is slightly lower than the stated: 151 instead of 155 Newtono-meters, at 3989 rpm. Well, the scandal did not happen - 4 Newton-meters could well "get lost" due to fuel, and in general, such a dispersion fully fits into the error. Let's see what Kia will show.
Rio has the most powerful motor in class: with a volume of 1591 cm. Cube. It develops 123 liters. with. At 6300 rpm, and the peak of torque 155 Newtono-meters falls on 4300 rpm. And what will be shown?
At first, almost happened to the sensation: Rio did not reach the stated indicators! A little bit, but did not reach. What is the reason? Are rumors confirmed? No: After examining the characteristics of Rio, Andrei came to the conclusion that the measurement should be done on not the 4th, but on the 5th gear. Why? That's right, because Rio with this motor is a 6-speed gearbox.
And immediately everything became in place: the booth showed that the engine produces 124.1 liters. with. At 6304 rpm, and the peak of the torque of 155.5 Newtono-meters falls on 4362 rpm.
Well, the sensation did not happen: both tested Tabun cars under the hood correspond to the declared. However, we were alerted the reaction of other dealers, flatly refused to provide cars for measurements: what are they fear?
We decided to figure out this in any way, so in the near future we plan to drive all "state employees" to the dinitend. And then - and models of other classes, including used to find out how many "horses" lose the motors during runs 100, 150, 200 thousand kilometers. And deal with who wear out faster - turbocharged or "atmospheric"? Gasoline or diesel engines? And how does a hybrid feel at 300 thousand kilometers? We hope that the dynamometer stand "will tell" more than any diagnosis! To the question of real power we will return, because the topic is interesting.
We bring to your attention a video report on the tests from our partners, the canal Test-Drive.tv..
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Horsepower - a unit of measure that does not have a single standard in the world, although in most countries and adhere to one numerical value. Horsepower is not included in the generally accepted international measurement system, and its official application was canceled in Russia. Meanwhile, this measure is used not only in everyday life, but also at the state level.
What is measured in horsepower
In horsepower - then the amount of mechanical work, which is performed for a certain period of time. The most common indicator is kilograms per meter per second. It is mainly used in relation to vehicles and some other mechanisms.
In Russia, at the rate of one horsepower, transport tax is calculated, and in the documents for vehicles, equipped with an engine, this unit of measurement is often used to indicate its power.
What is horsepower
This measure was introduced in the end of the 18th century in England. Technical progress and widespread use of steam machines revealed the need for a general standard for determining their performance.
The method of practical measurements made when working performed by a living horse under certain conditions calculated that in 1 second 1 Horse is capable of moving to a distance of 1 meter weight of 75 kg - this indicator and was taken for one horsepower.
Standard power measurement units
In the international measurement system, the official unit for determining the power is approved by Watt (1 kilowatt \u003d 1000 watts). This measure will be the same all over the world.
In watts, the power is measured as the rate of transmitted energy or as the amount of operation produced during a certain time.
In connection with the Unified World Standard, many car manufacturers, as well as other vehicles and mechanisms in the technique documents indicate the engine power in watts. However, in our country, each horsepower in the car affects the amount of transport tax, therefore it is more convenient to know the engine power level of its car in these units.
Metric horsepower
The most common calculus of horsepower (l. P.) Occurs in the metric system. For calculation, kilogram of weight gains is used, and the measurement of the distance to which it is moved is produced in meters.
In this case, one horsepower is 735,49875 watts, which is equivalent to 0.74 kW.
One kilowatt will be 1.36 liters. with.
Horsepower table
Knowing the calculation formula, you can easily translate digital indicators from some units of measurement to others, but if there is no desire to do calculations, you can use the comparative table. The following numeric indicators are relevant for the metric measurement system.
The difference between the calculation of horsepower in America and the UK
In connection with the application in a number of countries, for example, in the United States and Great Britain, feet and pounds as lengths of length and weight, their calculation of horsepower will be different from the world's world states, including in Russia.
In the traditional system of measuring these countries, one horsepower will be 745,6999 W (0.746 kW) and be 1,014 from metric horsepower. With equal indicators in this unit of measurement, the car engine, to evaluate the feet and pounds, in the process of actual work will be more powerful.
However, in most cases, the engine power in the accompanying documents is indicated in kW, therefore it is possible to recalculate it according to the standard formula.
Often real power indicators differ from factory parameters and makes sense to produce real measurements:
- putting a car on a dynamometer stand - the most accurate type of diagnosis;
- having installed additional electronic equipment in it (which is advisable only for vehicles in need of constant control of this indicator, as the service and purchase of special equipment will cost Neszayevo);
- or checking using an application loaded to a laptop that connects through the cable to the car and processes during test races.
Features of the definition of gross and net engine power
Thanks to a peculiar system for measuring the power of the engine used on factories producing vehicles in Japan and some owned by the United States, the amount of horsepower in cars made by them differed from the actual during operation.
Business in the so-called net power and gross power. When measuring the first indicator, the energy consumption is taken into account for the operation of the accompanying units - cooling systems, generator, drive belts. In the calculations of gross power, their influence is not taken into account. Therefore, real indicators for different methods of measurement can differ significantly - by 10-25 percent.
Machines, in the documents of which engine power is spelled out based on the gross indicator, there will be weaker vehicles with identical digital values \u200b\u200bof non-net measurements.
Since in Russia, the value of the tax paid for it depends on the number of horsepower in the vehicle, it is better to find out the real engine values \u200b\u200bto avoid overpays, which in certain cases may be very significant. Especially, if you have to not just add non-existent horsepower for payment by identical tariff, but also multiplying their total amount at an increased rate (this may occur if theoretical and actual indicators will be in different price groups for calculating transport payments, for example, Documents 155 l. p., and in fact less 150, etc.).
Consider 5 popular methods. how to calculate car engine power Using such data as:
- engine turnover,
- motor volume
- torque,
- effective pressure in the combustion chamber,
- fuel consumption,
- the performance of nozzles,
- weight car
- overclocking time up to 100 km.
Each of the formulas on which will be made engine capacity calculation The car is pretty relative and cannot with 100% accuracy to identify a real horsepower driving machine. But making calculations by each of the above garage options, relying not certain indicators, you can calculate, at least, the average value whether it is a stock or tuning engine, literally with a 10 percent error.
Power - The energy generated by the engine, it is converted to the torque on the outlet of the DVS. This is not a constant value. Next to the maximum power values \u200b\u200bare always indicated by turnover at which it is possible to achieve it. The maximum point is achieved with the greatest mean effective pressure in the cylinder (depends on the quality of filling the fuel mixture, completeness of combustion and heat loss). The largest power of modern motors outline on average at 5500-6500 rpm. In the automotive sphere, measuring the power of the engine is taken in horsepower. Therefore, since most results are displayed in kilowatts you will need
How to calculate power through torque
The easiest calculation of the engine power of the car can determine the dependence of torque and revolutions.
Torque
The force multiplied by the shoulder of its application, which can give the engine to overcome one or other resistance to movement. Determines the speed of achieving the maximum power by the motor. Calculated torque formula from engine volume:
MKP \u003d VHHPE / 0,12566where
- VH - engine operating volume (L),
- PE is an average effective pressure in the combustion chamber (bar).
Engine speed
The rotation speed of the crankshaft.
The formula for calculating the power of the engine internal combustion of the car is as follows:
P \u003d MK * N / 9549 [kW]Where:
- MK - engine torque (Nm),
- n - crankshaft turnover (rpm),
- 9549 - the coefficient, so that turns to substitute precisely in rpm, and not by the cosine of alpha.
Since by the formula, we will get the result from kW, then when necessary, you can also convert into horsepower or simply multiplied by the coefficient of 1.36.
Using these formulas is the easiest way to translate torque into power.
And in order not to go into all these details, the quick calculation of the power of DVS online, you can produce using our calculator.
If you do not know the torque of the engine of your car, then to determine its power in kilowatts, you can also use the formula of this type:
NE \u003d VH * PE * N / 120 (kW), where:
- VH - Engine Volume, cm³
- n - rotational speed, rpm
- pE is an average effective pressure, MPa (on conventional gasoline engines leaves about 0.82-0.85 MPa, forced - 0.9 MPa, and for a diesel engine from 0.9 and to 2.5 MPa, respectively).
To obtain the power of the engine in the "horses", and not kilowatts, the result should be divided by 0.735.
Calculation of the power of the engine by air consumption
The same approximate calculation of the engine power can be determined by air consumption. The function of such a calculation is available to those who have an on-board computer, because it is necessary to fix the flow value when the car engine is on the third transmission, up to 5.5 thousand revolutions. The obtained value with DMRV is divided by 3 and get the result.
GB [kg] / 3 \u003d p [hp]
Such a calculation, as well as the previous one, shows the gross capacity (booth test of the engine without taking into account losses), which is 10-20% higher than the actual one. And it is also worth considering that the testimony of the DMRV sensor is highly dependent on its pollution and calibrations.
Calculation of power by weight and time of overclocking up to hundreds
Another interesting way to how to calculate the engine power on any form of fuel, be it gasoline, diesel or gas - over the dynamics of overclocking. To do this, using the weight of the car (including pilot) and overclocking time to 100 km. And so that the capacity calculation formula is as close as possible to the truth, it is also necessary to take into account the losses on the slip depending on the type of drive and the speed of the reaction of different gearboxes. Approximate loss when starting for front-wheel drive will be 0.5 sec. and 0.3-0.4 at the rear-wheel drive cars.
Using this pot power calculator, which will help determine the engine power on the basis of the dynamics of overclocking and mass, you can quickly and fairly accurately learn the power of your iron horse is not intelligible into specifications.
Calculation of the power of DVS on the performance of nozzles
No less effective indicator of the power engine is. Previously, we considered its calculation and the relationship, therefore, labor, to calculate the amount of horsepower according to the formula, will not be. Calculation of the intended power occurs according to such a scheme:
Where, the load coefficient is not more than 75-80% (0.75 ... 0.8) composition of the mixture at maximum performance somewhere 12.5 (enriched), and the BSFC coefficient will depend on what kind of engine, atmospheric or turbocharged (Atmo - 0.4-0.52, for turbo - 0.6-0.75).
Learning all the necessary data, drive in the appropriate calculator cells and by pressing the "Calculate" button you immediately get the result that will show the real power of the engine of your car with a minor error. Note that you do not necessarily know all the parameters presented, you can clear the power of the DVS separately by the method.
The value of the functional of this calculator is not in the calculation of the power of the stock car, and if your car has been tuning and its mass and power faced some changes.
The concept of "horsepower of the car" was introduced in the 18th century James Watt. This is a parameter showing the power of the car compared with the horse force.
1 horsepower or hp equal to the power required for the rise of 75 kilogram cargo to the height of one meter per 1 second. In some cases, it is customary to translate L.S. In kilowatts - then 1 horsepower will be 735.5 W or 0.735 kW.
To determine the power in L.S. A specific car, it is necessary to translate the kW specified in the passport data into horsepower. This is done like this: the given values \u200b\u200bin kilowatts are simply divided by 0.735. The final value and will mean the horsepower of a certain car.
Several examples for comparison.
- Nissan Mikra with an engine, volume of 1 l, has a power indicator of 48 kW. To determine the parameter in horsepower, it is necessary to divide 48 / 0.735. It turns out 65.3 or rounded - 65 horses.
- The sports version of the famous Volkswagen golf with a TSI motor on 2.0 liters has a power of 155 kW. Sharing a number 0.735, we get a value in hp - 210.
- In the passport data of the domestic "Niva", 58 kW is indicated, which is 79 hp Often this value is rounded, and the value of 80 hp is indicated.
There is another way to calculate horses. Almost on any large service station there is a special installation, easily determining how much horsepower in the car. The car is raised to the platform, fixed, the accelerator pedal is squeezed until it stops. In a few minutes, the computer will calculate the value.
It is customary to distinguish between 2 measurement systems: domestic and European. Both equates hp to 75 kg x m / s.
Thus, the horsepower in the car is equal to the divided value of kW at 0.735. Kilowatt is a metric unit for measuring horsepower. It is comparable with the work produced in 1 second when lifting the cargo weighing 75 kg to a height of one meter. All this, taking into account earthly attraction.
The modern car is considered highly efficient if its engine has a greater power in relation to the mass of the vehicle. Or so: The easier the body, the greater the power parameter will speed up the car.
This is clearly visible below on the example of high-performance cars.
- Dodge Viper with a capacity of 450 hp It has a total weight of 3.3 tons. Power / weight ratio is 0.316, overclocking up to hundreds - 4.1 s.
- Ferrari 355 F1 with a capacity of 375 hp - Full weight of 2.9 tons, ratio - 0.126, acceleration to hundreds - 4.6 s.
- Shelby Series 1 with a capacity of 320 hp - Complete weight of 2.6 tons, ratio - 0.121, acceleration to hundreds - 4.4 s.
Some car publications write that the price of the car is determined only by the "horses" under the hood. Is it so? And why is a torque or km prescribe in the car?
Km - this is a consequence of the impact on the lever, familiar to everyone in physics lessons. Accordingly, the term measurement in Nm is displayed. In the OI, the role of the lever is performed by the crankshaft, and the power or energy is born when combustion of fuel. It acts on the piston, creating km.
It turns out that the value of the CM is also important, as is the power. Only the last parameter implies another work performed per unit of time. It shows how many times per unit of time IT creates km. Power is due to the amplitude of the rotation of the power plant or turnover, and therefore depends on the CM. Actually, therefore, it is calculated in kilowatts.
Now directly about the impact.
- The power of the car is required to forcing certain resistance. What it is higher, the more the car is capable of overcoming. In this case, the friction and rolling forces are opposing forces, the resistance of the oncoming air and so on.
- Km affects the possibilities of the car directly, because next to the "horses" parameter is always written, on which the optimal power depends.
Thus, a carved horsepower of the car is nothing without torque, because it is the last indicator that determines the dynamics of overclocking, affects the activation of the air boom.
Horsepower directly affects the transport tax determined by the country's law. What she is higher, the more it will be necessary to pay for the car.
Calculate the car tax or TN can both forces using the following formula: L.S. Car x Actual rate and component derived by the attitude of the timing of the vehicle to the total number of months per year.
Example 1.
Lada Vesta is equipped with an engine, developing 105 hp If the owner lives in Moscow, then the tax rate for today is 12 rubles. It turns out that the cost of TN for 1 year will be equal to:
- 12 × 105 \u003d 1260 rubles.
Example 2.
Volkswagen golf, equipped with a 2.0 TSI GTI engine with km 152 kW, has a capacity of 207 hp Calculate the tax:
- 12 × 207 \u003d 2484 ruble.
Example 3.
Top car Ferrari GTB coupe has under the hood of 270 horses. Accordingly, the tax will be:
- 12 × 270 \u003d 3240 rubles.
