Крутящий момент двигателя на что влияет: мощность или крутящий момент? — журнал За рулем

Все про мощность двигателя и крутящий момент — журнал За рулем

Mожет ли крутящий момент существовать при нулевой мощности? Способна ли коробка передач увеличить мощность? Как распределена мощность между ведущими колесами, когда заднеприводный автомобиль с блокированным дифференциалом движется по плохой дороге? На эти и другие каверзные вопросы по физике процесса предлагают ответить Михаил Колодочкин и Эдуард Коноп. Проверим себя?

Gonschiki MRW_zr 11_15

Материалы по теме

Мощность — это работа, совершаемая за единицу времени. Можно сказать, что мощность — это скорость выполнения работы. Например, трактор за секунду накосит больше сена, чем газонокосилка. Основная единица измерения мощности — ватт (Вт). Численно она характеризует собой работу в один джоуль (Дж), совершенную за одну секунду. Распространенная внесистемная единица — лошадиная сила, равная 0,736 кВт. Для примера: мощность двигателя 170 кВт соответствует 231,2 л.с.

А что такое крутящий момент? Со школы помним про силу, помноженную на плечо, — измеряется в ньютон-метрах (Н·м). Смысл очень простой: если момент, приложенный к колесу радиусом 0,5 м, составляет, скажем, 2000 Н·м, то толкать наш автомобиль будет сила в 4000 Н (с округлением — 400 кгс). Чем больше момент, тем энергичнее мотор тащит машину.

Связь между этими двумя основными параметрами неразрывная: мощность — это крутящий момент, умноженный на угловую скорость (грубо говоря, обороты) вала. А может ли существовать крутящий момент при нулевой мощности? Способна ли коробка передач увеличить мощность?

Tires_1600

Оцените уровень своих знаний — ответьте на вопросы. Это не так просто, как кажется на первый взгляд. Исходные условия: разного рода потери, например на трение, не учитываем, а нагрузки на колёса и условия сцепления шин с покрытием считаем одинаковыми, если не оговорено иное.

1. Автомобиль в глубокой колее сел на брюхо: ведущие колеса вертятся, не касаясь земли. Водитель упрямо газует. Какую полезную мощность может при этом выдать двигатель?

А — паспортную;

Б — в зависимости от оборотов;

В — нулевую;

Г — в зависимости от включенной передачи.

Правильный ответ: В. Автомобиль не движется, мотор не совершает полезной работы. Значит, и полезная мощность равна нулю.

2. Заднеприводный автомобиль с блокированным дифференциалом движется по плохой дороге. Как распределена мощность между ведущими колесами?

А — поровну;

Б — обратно пропорционально частоте вращения каждого из колес;

В — в зависимости от сил сцепления с покрытием;

Г — прямо пропорционально частоте вращения каждого из колес.

Правильный ответ: В.  При блокированном дифференциале ведущие колеса вращаются с одинаковой скоростью, но моменты на них не выравниваются — они зависят только от сцепления с дорогой. Следовательно, реализуемые колесами мощности тоже определяются силами сцепления с покрытием.

колесо

3. На что влияет мощность мотора?

А — на динамику разгона;

Б — на максимальную скорость;

В — на эластичность;

Г — на все перечисленные параметры.

Правильный ответ: Г. Часто полагают, что машину тащит исключительно крутящий момент. Но поставщиком крутящего момента является мотор. Если тот перестанет снабжать колеса энергией, то все динамические параметры будут равны нулю. Например, резко тронуться на повышенной передаче не удастся: при низких оборотах просто не хватит мощности. А она-то и определяет запас энергии, которую способен выдать двигатель. И влияет на все перечисленные параметры.

90000 What is Engine Torque? It’s Characteristics & Formula-CarBikeTech 90001 90002 Engine Torque Definition and Formula: 90003 90004 90005 What is Engine Torque? 90006 90007 90004 Torque, in simple terms, is ‘90005 Twisting or Turning Force 90006’. It is the tendency of a force to rotate an object about an axis. In automotive terms, it is the measure of rotational effort applied on engine crankshaft by the piston. 90007 90004 Torque = Force x Distance. The SI system uses 90005 Newton-metre 90006 (Nm) to measure the torque.The other units are 90005 kilogram-meter 90006 (Kg-m) in metric and 90005 feet-pound-force 90006 ‘(ft-lb) in imperial / British units. 90007 90020 Torque Definition Diagram 90004 Every engine is designed and built for a specific purpose. Hence, its output varies depending upon its application. The torque output of an automotive engine mainly depends on its stroke-to-bore ratio, compression ratio, combustion pressures & speed in rpm. Most ‘under-square’ engines which have 90005 higher stroke-length than its bore diameter 90006, tend to develop the high amount of ‘90005 low-end torque 90006’.The amount of torque that an engine can exert depends upon the engine RPM. 90007 90004 Different engine designs / configurations develop different torque characteristics such as 90005 peak curve / flat curve 90006. Most automotive engines produce useful torque output within a narrow band of the engine’s entire speed range. In petrol engines, it characteristically starts at around 90005 1000-1200 90006 rpm and reaching a peak in the range of 2,500-4,000 rpm. Whereas in a diesel engine, it starts at around 90005 1500-1700 rpm 90006 and peaking at 2000-3000 rpm.Bugatti Veyron is one of the cars with the highest torque figures. 90007 90035 Engine Torque Graph 90036 How to calculate engine torque: 90037 90004 If you know the Horse-Power of the engine, then you can use the following formula — 90007 90004 90005 Torque = 5252 x HP / RPM 90006 90007 90036 Why is engine torque important? 90037 90004 Torque and Horse-Power are the twin outputs of an engine. They are related and proportional to each other by speed. The ‘90005 torque-band 90006’ in an engine curve represents its 90005 pulling ability 90006 which determines a vehicle’s ‘90005 driveability 90006’ & ‘90005 acceleration 90006’.Torque is most needed while moving a vehicle from the stand-still and / or climbing a slope. Similarly, heavier is the vehicle or a vehicle with full rated load requires a higher amount of torque to pull it and get it moving. In a conventional engine, the horsepower governs vehicle’s top speed (thru ‘gear ratios) whereas torque controls its acceleration / pick-up. The rate of acceleration also depends on the vehicle’s weight and the ‘load’ carried by the vehicle. 90007 90036 Flat-Curve vs Peak-Curve engine torque: 90037 90004 Most petrol engines normally produce a considerably high amount of ‘90005 low-end-torque 90006’.However, usually, they exhibit ‘90005 peak-curve 90006’ torque in the shape of the ‘peak’ of a hill. In ‘90005 peak-curve 90006’ design, the torque peaks at the middle of the engine rpm range (around 2500-3000 rpm). After this, it starts to fade out rapidly while the horsepower still keeps rising. The HP reaches its maximum value later at a higher engine rpm and then fades out at the red-line. 90007 90066 Peak vs Flat Curve Torque 90004 Most modern diesel engines deliver a ‘90005 flat-curve 90006’ torque.In ‘flat-curve’ design, the engine produces maximum torque at a ‘90005 lower-to-middle-end 90006’ of the engine speed i.e. approx. 1500 rpm onward. Its value remains almost the same or ‘flat’ across most of the engine speed range (2500-4000 rpm). This helps in better acceleration and effects fewer gear shifts while driving. 90007 90036 What is Low-End Torque? 90037 90004 Often manufacturers use this term to describe an engine’s torque performance. ‘90005 Low-End-Torque 90006’ is the amount of torque that engine produces at the lower engine rpm band i.e. 90005 between 1000-2000 rpm 90006. This rpm band is very crucial when moving a vehicle from stand-still or driving in slow-speed conditions such as in traffic. If the engine generates a greater amount of torque at the lower end of the rpm band, it implies that the engine has higher ‘90005 low-end-torque 90006’ or 90005 better pulling ability at slow speeds 90006. It also means that the engine can move the vehicle quickly from stand-still, pull heavier loads or climb a slope relatively easily as the case may be without revving hard.90007 90036 Engine Torque and Efficiency: 90037 90004 The engine torque reaches its peak value at a speed where it is most efficient. In other words, the engine efficiency is at the maximum at a speed where it produces its peak-torque. If you raise the engine above this speed, its torque starts to decrease because of the increased friction of the engine’s moving parts. So even if you rev ​​the engine over & above the peak-torque speed, the torque does not increase any further. 90007 90004 Engine torque is multiplied by gears.Lower the gear selected (i.e. 1 90090 st 90091 gear which has a high gear ratio), greater is the pulling ability of the engine. Therefore, the vehicle’s pulling ability is highest in the first gear. However, if you rev ​​the engine further in 1 90090 st 90091 gear, it reaches its limit after some time; thereby prompting the driver to shift to the next gear. In contrast, if you change gears before the engine torque reaches its ‘peak’ value, the vehicle might lose its acceleration. This is because the wheels would not get enough force to rotate.Thus, compelling the driver to shift back to the previous / lower gear. 90007 90036 Engine Torque and Driving: 90037 90004 Best fuel efficiency can be obtained by changing the gears within the vehicle’s ‘Power-Band’ and 90005 changing gears as close to the peak torque value 90006 as possible. Also, to get better efficiency, select the correct gear / s corresponding to the vehicle speed / engine rpm as recommended by the vehicle manufacturer. 90007 90004 90005 1. Highway Scenario: 90006 90007 90004 90005 Topmost available Gear (i.e. 5th or 6th or so on) + Lowest Engine Speed ​​= Best Fuel Efficiency 90006 90007 90004 90005 2. When climbing a slope / gradient: 90006 90007 90004 90005 Low gear (i.e. 1st) + High engine speed = Least Fuel Efficiency but more pulling ability. 90115 90006 90007 90004 Once your vehicle goes past 60 Km / h such as on the highway, you do not need high engine rpm to keep it going. This means that while cruising on highways / motorways, use the topmost gear and keep the engine rpm to below 2500 to get maximum efficiency.Similarly, while climbing a slope you need to use the lower gear (i.e. 1st gear) and higher engine rpm to pull the vehicle (and load if any) against the force of gravity. However, it will affect fuel efficiency. 90007 90120 Power Torque Fuel Consumption 90004 These values ​​are mentioned in every Owner’s Manual. Having said this, always running the engine on ‘max-power / speed’ or revving the engine to the ‘90005 Red Line 90006’ zone is not necessary unless you are running a race as it will only result in 90005 burning of extra fuel 90006 .90007 90004 Remember that such extra fuel either burned or saved will make a lot of difference at the end of the journey — be it short or long … !!! 90007 90004 90005 Read more: What is Horse Power? 90006 90007 90004 About CarBikeTech 90007 90004 CarBikeTech is a technical blog with experience of over 20 years in the automobile field. It regularly publishes specific technical articles on automotive technology. 90007 90004 View all posts by CarBikeTech 90007 .90000 Power vs. Torque — x-engineer.org 90001 90002 In this article we are going to understand how the 90003 engine torque 90004 is produced, how 90003 engine power 90004 is calculated and what is a 90003 torque and power curve 90004. Also, we are going to have a look at the engine torque and power maps (surfaces). 90009 90002 By the end of the article, the reader will be able to understand the difference between torque and power, how they affect the longitudinal dynamics of the vehicle and how to interpret torque and power curves at full load.90009 90012 Definition of torque 90013 90002 90003 Torque 90004 can be regarded as a 90003 turning force 90004 applied on an object. Torque (vector) is the cross product between a force (vector) and a distance (scalar). The distance, also called the 90003 lever arm 90004, is measured between the force and the turning point. Similar to a force, torque is a vector and is defined by an amplitude and a direction of rotation. 90009 90002 Image: Tightening torque at wheel bolt 90009 90002 Imagine that you want to tighten / loosen the bolts of a wheel.Pushing or pulling the handle of the wrench connected to a nut or bolt, produces a torque (turning force) that loosens or tightens the nut or bolt. 90009 90002 The torque 90027 T [Nm] 90028 is the product of the force 90027 F [N] 90028 and the length of the lever arm 90027 a [m] 90028. 90009 \ [\ bbox [# FFFF9D] {T = F \ cdot a} \] 90002 In order to increase the magnitude of the torque we can either increase the force, the length of the lever arm or both. 90009 90002 90003 Example 90004: Calculate the torque obtained on the bolt if the arm of the wrench has 90027 0.25 m 90028 and the applied force is 90027 100 N 90028 (which is approx. Equivalent with a pushing force of 90027 10 kg 90028) 90009 \ [T = 100 \ cdot 0.25 = 25 \ text {Nm} \] 90002 The same torque could be obtained if the lever arm was 90027 1 m 90028 and the force only 90027 25 N 90028. 90009 90002 The same principle applies to internal combustion engines. The torque at the crankshaft is produced by the force applied on the conrod journal through the connecting rod. 90009 90002 Image: Torque at crankshaft 90009 90002 The torque 90027 T 90028 will be produce at the crankshaft on each conrod journal, every time the piston is in the power stroke.The lever arm 90027 a 90028 in this case is the 90003 crank radius (offset) 90004. 90009 90002 The magnitude of the force 90027 F 90028 depends on the combustion pressure within the cylinder. The higher the pressure in the cylinder, the higher the force on the crankshaft, the higher the output torque. 90009 90002 Image: Engine torque calculation function of cylinder pressure 90009 90002 The length of the lever arm has impact on the overall 90003 engine balance 90004. Increasing it too much can lead to engine imbalance, which results in higher forces in the crankshaft journals.90009 90002 90003 Example 90004: Calculate the torque at the crankshaft for an engine with the following parameters: 90009 90078 90079 90080 90081 Cylinder bore, B [mm] 90082 90081 85 90082 90085 90080 90081 Cylinder pressure, p [bar] 90082 90081 12 90 082 90085 90080 90081 Crank offset, a [mm] 90082 90081 62 90082 90085 90098 90099 90002 First, we calculate the area of ​​the piston (assuming the the piston head is flat and its diameter is equal with the bore of the cylinder): 90009 \ [A_p = \ frac {\ pi B ^ 2} {4} = \ frac {\ pi \ cdot 0.2 \] 90002 Second, we’ll calculate the force applied to the piston. To get the force in 90027 N 90028 (Newton), we’ll use the pressure converted in 90027 Pa 90028 (Pascal). 90009 \ [F = p \ cdot A_p = 120000 \ cdot 0.0056745 = 680.94021 \ text {N} \] 90002 Assuming that all the force in the piston goes into the connecting rod, the torque is calculated as: 90009 \ [T = F \ cdot a = 680.94021 \ cdot 0.062 = 42.218293 \ text {Nm} \] 90002 The standard unit of measurement for torque is 90027 N · m 90028 (Newton meter).Especially in the USA, the unit of measurement for engine torque is 90027 lbf · ft 90028 (foot-pounds). The conversion between 90027 N · m 90028 and 90027 lbf · ft 90028 is: 90009 \ [\ begin {split} 90120 1 \ text {lbf} \ cdot \ text {ft} & = 1.355818 \ text {N} \ cdot \ text {m} \\ 90120 1 \ text {N} \ cdot \ text {m} & = 0.7375621 \ text {lbf} \ cdot \ text {ft} 90120 \ end {split} \] 90002 For our particular example, the torque in imperial units (USA) is: 90009 \ [T = 42.218293 \ cdot 0.7375621 = 31.138615 \ text {lbf} \ cdot \ text {ft} \] 90002 Torque 90027 T [N] 90028 can also be expressed as a function of the mean effective pressure of the engine.90009 \ [T = \ frac {p_ {me} V_d} {2 \ pi n_r} \] 90002 where: 90120 90027 p 90132 me 90133 [Pa] 90028 — mean effective pressure 90120 90027 V 90132 d 90133 [m 90139 3 90140 ] 90028 — engine displacement (volume) 90120 90027 n 90132 r 90133 [-] 90028 — number of crankshaft rotations for a complete engine cycle (for a 4-stroke engine 90027 n 90132 r 90133 = 2 90028) 90009 90012 Definition of power 90013 90002 In physics, 90003 power 90004 is the work done in time or, with other words, is 90003 the rate of doing work 90004.In rotational systems, power 90027 P [W] 90028 is the product of the torque 90027 T [Nm] 90028 and angular velocity 90027 ω [rad / s] 90028. 90009 \ [\ bbox [# FFFF9D] {P = T \ cdot \ omega} \] 90002 The standard unit of measurement for power is 90027 W 90028 (Watt) and for rotational speed is 90027 rad / s 90028 (radian per second) . Most of the vehicle manufacturers are providing the power of the engine in 90027 bhp 90028 (brake horse power) and the rotational speed in 90027 rpm 90028 (rotations per minute).Therefore, we are going to use conversion formulas for both rotational speed and power. 90009 90002 To convert from 90027 rpm 90028 to 90027 rad / s 90028, we use: 90009 \ [\ omega \ text {[rad / s]} = N \ text {[rpm]} \ cdot \ frac {\ pi} { 30} \] 90002 To convert from 90027 rad / s 90028 to 90027 rpm 90028, we use: 90009 \ [N \ text {[rpm]} = \ omega \ text {[rad / s]} \ cdot \ frac {30 } {\ pi} \] 90002 The engine power can also be measured in 90027 kW 90028 instead of 90027 W 90028 for a more compact value.To convert from 90027 kW 90028 to 90027 bhp 90028 and reverse, we use: 90009 \ [\ begin {split} 90120 P \ text {[bhp]} & = 1.36 \ cdot P \ text {[kW]} \\ 90120 P \ text {[kW]} & = \ frac {P \ text {[bhp]}} {1.36} 90120 \ end {split} \] 90002 In some cases you might find 90027 HP 90028 (Horse Power) instead of 90027 bhp 90028 as unit of measurement for power. 90009 90002 Having rotational speed measured in 90027 rpm 90028 and torque in 90027 Nm 90028, the formula to calculate 90003 power 90004 is: 90009 \ [\ begin {split} 90120 P \ text {[kW]} & = \ frac {\ pi \ cdot N \ text {[rpm]} \ cdot T \ text {[Nm]}} {30 \ cdot тисячі} \\ 90120 P \ text {[HP]} & = \ frac {1.36 \ cdot \ pi \ cdot N \ text {[rpm]} \ cdot T \ text {[Nm]}} {30 \ cdot тисячі} 90120 \ end {split} \] 90002 90003 Example 90004. Calculate the engine power in both 90027 kW 90028 and 90027 HP 90028, if the engine torque is 90027 150 Nm 90028 and engine speed is 90027 2800 rpm 90028. 90009 \ [\ begin {split} 90120 P & = \ frac {\ pi \ cdot 2800 \ cdot 150} {30 \ cdot 1 тисячі} = 44 \ text {kW} \\ 90120 P & = \ frac {1.36 \ cdot \ pi \ cdot 2800 \ cdot 150} {30 \ cdot 1 тисячі} = 59.8 \ text {HP} 90120 \ end {split} \] 90012 Engine dynamometer 90013 90002 Engine speed is measured using a sensor on the crankshaft (flywheel).Ideally, to calculate power, we should also measure the torque at the crankshaft with a sensor. Technically, this is possible but not applied in the automotive industry. Because of the operating conditions of the crankshaft (temperatures, vibrations), measuring engine torque with a sensor is not a reliable technique. Also, the cost of a torque sensor is quite high. Therefore, engine torque is measured on the full range of speed and load, using a 90003 dynamometer 90004 (test bench), and mapped (stored) into the engine control unit.90009 90002 Image: Engine dynamometer schematic 90009 90002 The dynamometer is basically a brake (mechanical, hydraulic or electrical) which absorbs the power produced by the engine. The most used and best type of dynamometer is the 90003 electric dynamometer 90004. This is actually an 90003 electric machine 90004 that can be operated as a 90003 generator 90004 or 90003 motor 90004. By varying the generator’s load torque, the engine can be put in any operating point (speed and torque).Also, with the engine at fuel cut (no fuel injection), the generator can be run as an electric motor to spin the engine. This way engine friction and pumping torque losses can be measured. 90009 90002 For an electric dynamometer, the rotor is connected to the crankshaft. The link between rotor and stator is electromagnetic. The stator is fixed through a lever arm to a 90003 load cell 90004. To balance the rotor, the stator will push against the load cell. The torque 90027 T 90028 is calculated by multiplying the force 90027 F 90028 measured in the load cell with the length of the lever arm 90027 a 90028.90009 \ [T = F \ cdot a \] 90002 The engine parameters: brake torque, brake horse power (bhp) or brake specific fuel consumption (BSFC) contain the keyword «brake» because a dynamometer (brake) is used to measure them . 90009 90002 What comes out from a dynamometer engine test are 90003 torque maps 90004 (surfaces) which give the value of the engine torque at a specific engine speed and load (stationary operating points). The load of the engine is equivalent to the position of the accelerator pedal.90009 90002 Example of 90003 torque map for a gasoline, spark ignition (SI) engine 90004: 90009 90078 90079 90080 90274 90003 Engine 90120 torque 90120 [Nm] 90004 90082 90280 Accelerator pedal position [%] 90082 90085 90080 90081 90003 5 90004 90082 90081 90003 10 90004 90082 90081 90003 20 90004 90082 90081 90003 30 90004 90082 90081 90003 40 90004 90082 90081 90003 50 90004 90082 90081 90003 60 90004 90082 90081 90003 100 90004 90082 90085 90080 90318 Engine 90120 speed 90120 [rpm] 90082 90081 90003 800 90004 90082 90081 45 90082 90081 90 90082 90081 107 90082 90081 109 90082 90081 110 90082 90081 111 90082 90081 114 90082 90081 116 90082 90085 90080 90081 90003 1300 90004 90082 90081 60 90082 90081 105 90082 90081 132 90082 90081 133 90082 90081 134 90082 90081 136 90082 90081 138 90082 90081 141 90082 90085 90080 90081 90003 1800 90004 90082 90081 35 90082 90081 89 90082 90081 133 90082 90081 141 90082 90081 1 42 90082 90081 144 90082 90081 145 90082 90081 149 90082 90085 90080 90081 90003 2300 90004 90082 90081 19 90082 90081 70 90082 90081 133 90082 90081 147 90082 90081 148 90082 90081 150 90082 90081 151 90082 90081 155 90082 90085 90080 90081 90003 2800 90004 90082 90081 3 90082 90081 55 90082 90081 133 90082 90081 153 90082 90081 159 90082 90081 161 90082 90081 163 90082 90081 165 90082 90085 90080 90081 90003 3300 90004 90082 90081 0 90082 90081 41 90082 90081 126 90082 90081 152 90082 90081 161 90082 90081 165 90082 90081 167 90082 90081 171 90082 90085 90080 90081 90003 3800 90004 90082 90081 0 90082 90081 33 90082 90081 116 90082 90081 150 90082 90081 160 90082 90081 167 90082 90081 170 90082 90081 175 90082 90085 90080 90081 90003 4300 90004 90082 90081 0 90082 90081 26 90082 90081 110 90082 90081 155 90082 90081 169 90082 90081 176 90082 90081 180 90082 90081 184 90082 90085 90080 90081 90003 4800 90004 9008 2 90081 0 90082 90081 18 90082 90081 106 90082 90081 155 90082 90081 174 90082 90081 179 90082 90081 185 90082 90081 190 90082 90085 90080 90081 90003 5300 90004 90082 90081 0 90082 90081 12 90082 90081 96 90082 90081 147 90082 90081 167 90082 90081 175 90082 90081 181 90082 90081 187 90082 90085 90080 90081 90003 5800 90004 90082 90081 0 90082 90081 4 90082 90081 84 90082 90081 136 90082 90081 161 90082 90081 170 90082 90081 175 90082 90081 183 90082 90085 90080 90081 90003 6300 90004 90082 90081 0 90082 90081 0 90082 90081 72 90082 90081 120 90082 90081 145 90082 90081 153 90082 90081 159 90082 90081 171 90082 90085 90098 90099 90002 Example of 90003 power map for a gasoline, spark ignition (SI) engine 90004: 90009 90078 90079 90080 90274 90003 Engine 90120 power 90120 [ HP] 90004 90082 90280 Accelerator pedal position [%] 90082 90085 90080 90081 90003 5 90004 90082 90081 90003 10 90004 90082 90081 90003 20 90004 9 0082 90081 90003 30 90004 90082 90081 90003 40 90004 90082 90081 90003 50 90004 90082 90081 90003 60 90004 90082 90081 90003 100 90004 90082 90085 90080 90318 Engine 90120 speed 90120 [rpm] 90082 90081 90003 800 90004 90082 90081 5 90082 90081 10 90082 90081 12 90082 90081 12 90082 90081 13 90082 90081 13 90082 90081 13 90082 90081 13 90082 90085 90080 90081 90003 1300 90004 90082 90081 11 90082 90081 19 90082 90081 24 90082 90081 25 90082 90081 25 90082 90081 25 90082 90081 26 90082 90081 26 90082 90085 90080 90081 90003 1800 90004 90082 90081 9 90082 90081 23 90082 90081 34 90082 90081 36 90082 90081 36 90082 90081 37 90082 90081 37 90082 90081 38 90082 90085 90080 90081 90003 2300 90004 90082 90081 6 90082 90081 23 90082 90081 44 90082 90081 48 90082 90081 48 90082 90081 49 90082 90081 49 90082 90081 51 90082 90085 90080 90081 90003 2800 90004 90082 90081 1 90082 90081 22 90082 90081 53 90082 90081 61 90082 90081 63 90082 90081 64 90082 90081 65 90082 90081 66 90082 90085 90080 90081 90003 3300 90004 90082 90081 0 90082 90081 19 90082 90081 59 90082 90081 71 90082 90081 76 90082 90081 78 90082 90081 78 90082 90081 80 90082 90085 90080 90081 90003 3800 90004 90082 90081 0 90082 90081 18 90082 90081 63 90082 90081 81 90082 90081 87 90082 90081 90 90082 90081 92 90082 90081 95 90082 90085 90080 90081 90003 4300 90004 90082 90081 0 90082 90081 16 90082 90081 67 90082 90081 95 90082 90081 103 90082 90081 108 90082 90081 110 90082 90081 113 90082 90085 90080 90081 90003 4800 90004 90082 90081 0 90082 90081 12 90082 90081 72 90082 90081 106 90082 90081 119 90082 90081 122 90082 90081 126 90082 90081 130 90082 90085 90080 90081 90003 5300 90004 90082 90081 0 90082 90081 9 90082 90081 72 90082 90081 111 90082 90081 126 90082 90081 132 90082 90081 137 90082 90081 141 90082 90085 90080 90081 90003 5800 90004 90082 90081 0 90 082 90081 3 90082 90081 69 90082 90081 112 90082 90081 133 90082 90081 140 90082 90081 145 90082 90081 151 90082 90085 90080 90081 90003 6300 90004 90082 90081 0 90082 90081 0 90082 90081 65 90082 90081 108 90082 90081 130 90082 90081 137 90082 90081 143 90082 90081 153 90082 90085 90098 90099 90002 The electronic control module (ECM) of an ICE has the torque map stored in the memory.It calculates (interpolates) the engine torque function of the current engine speed and load. In the ECM, the load is expressed as intake manifold pressure for gasoline (spark ignition, SI) engines and injection time or fuel mass for diesel (compression ignition, CI) engines. The engine torque calculation strategy has corrections based on temperature and intake air pressure. 90009 90002 Plotting the torque and power data, function of engine speed and load, gives the following surfaces: 90009 90078 90079 90080 90081 90002 Image: SI engine torque surface 90009 90082 90081 90002 Image: SI engine power surface 90009 90082 90085 90098 90099 90002 For a better interpretation of the torque and power maps, a 2-D torque line can be plotted for a fixed value of the accelerator pedal position.90009 90078 90079 90080 90081 90002 Image: SI engine torque curves 90009 90082 90081 90002 Image: SI engine power curves 90009 90082 90085 90098 90099 90012 Engine torque and power at full load 90013 90002 As you have seen, the torque and power of an internal combustion engine depend on both engine speed and load. Usually, engine manufacturers are publishing the torque and curve characteristics (curves) at 90003 full load 90004 (100% accelerator pedal position). Full load torque and power curves highlight the maximum torque and power distribution through the whole range of engine speed.90009 90002 Image: Engine torque and power parameters at full load 90009 90002 The shape of the above torque and power curves are not from a real engine, the scope being to explain the main parameters. Nevertheless, the shapes are similar to the real characteristics of a spark ignited (gasoline), port injection, atmospheric engine. 90009 90002 Engine speed 90027 N 90132 e 90133 [rpm] 90028 is characterized by four main points: 90009 90002 90027 N 90132 min 90133 90028 — is the minimum stable engine speed at full load 90120 90027 N 90132 Tmax 90133 90028 — is the engine speed at maximum engine torque 90120 90027 N 90132 Pmax 90133 90028 — is the engine speed at maximum engine power; also called 90003 rated engine speed 90004 90120 90027 N 90132 max 90133 90028 — is the maximum stable engine speed 90009 90002 At minimum speed, the engine should run smoothly, without oscillations or stalling.The engine should also allow operation at the maximum speed without any structural damage. 90009 90002 The 90003 full load engine torque 90004 curve 90027 T 90132 e 90133 [Nm] 90028 is characterized by four points: 90009 90002 90027 T 90132 0 90133 90028 — engine torque at minimum engine speed 90120 90027 T 90132 max 90133 90028 — maximum engine torque (peak torque or 90003 rated torque 90004) 90120 90027 T 90132 P 90133 90028 — engine torque at maximum engine power 90120 90027 T 90132 M 90133 90028 — engine torque at maximum engine speed 90009 90002 Depending on the type of intake air (atmospheric or turbocharged) the peak torque can be either a point or a line.For turbocharged or supercharged engines, maximum torque can be kept constant between two engine speed values. 90009 90002 The 90003 full load engine power 90004 curve 90027 P 90132 e 90133 [HP] 90028 is characterized by four points: 90009 90002 90027 P 90132 0 90133 90028 — engine power at minimum engine speed 90120 90027 P 90132 max 90133 90028 — maximum engine power (peak power or 90003 rated power 90004) 90120 90027 P 90132 T 90133 90028 — engine power at maximum engine torque 90120 90027 P 90132 M 90133 90028 — engine power at maximum engine speed 90009 90002 The area between minimum engine speed 90027 N 90132 min 90133 90028 and maximum torque engine speed 90027 N 90132 Tmax 90133 90028 is called 90003 low end 90004 torque zone.The higher the torque in this area, the better the launch / acceleration capabilities of the vehicle. When the engine is operating in this area, at full load, if the road resistance increase, the engine speed will decrease, which will result in a drop of engine torque and an 90003 engine stall 90004. For this reason, this area is also called 90003 unstable torque region 90004. 90009 90002 The area between maximum torque engine speed 90027 N 90132 Tmax 90133 90028 and maximum power engine speed 90027 N 90132 Pmax 90133 90028 is called the 90003 power band 90004.During vehicle acceleration, for best performance, the gearshift (up) should be performed at maximum engine power. Depending on the gear ratios of the gearbox, after the gearshift, the selected gear will drop the engine speed at maximum torque, which will give optimum acceleration. Shifting the gears at maximum engine power will keep the engine speed within the power band. 90009 90002 The area between maximum power engine speed 90027 N 90132 Pmax 90133 90028 and maximum engine speed 90027 N 90132 max 90133 90028 is called 90003 high end 90004 torque zone.Higher torque results in higher output power, which translates in higher maximum vehicle speed and better acceleration at high speed. 90009 90002 When the engine speed is kept between maximum torque engine speed 90027 N 90132 Tmax 90133 90028 and maximum engine speed 90027 N 90132 max 90133 90028, if the vehicle road resistance increases, the engine speed will drop and the output torque will increase, thus compensating for the road load increase. For this reason, this area is called the 90003 stable torque region 90004.90009 90002 Below you can find some full load torque and power curves examples for different types of engines. Notice the shape of the curves function of the type of the engine (spark ignited or compression ignited) and type of air intake (atmospheric or turbo (super) charged). 90009 90012 Honda 2.0 engine torque and power at full load 90013 90078 90079 90080 90081 90003 Cylinders architecture 90004 90082 90081 4 in-line 90082 91111 90002 Image: Honda 2.0 SI engine — torque and power curves at full load 90009 90082 90085 90080 90081 90003 Fuel 90004 90082 90081 gasoline (SI) 90082 90085 90080 90081 90003 Engine capacity [cm 90139 3 90140] 90004 90082 90081 1998 90082 90085 90080 90081 90003 Fuel injection 90004 90082 90081 valve port 90082 90085 90080 90081 90003 Air intake 90004 90082 90081 atmospheric 90082 90085 90080 90081 90003 Valve timing 90004 90082 90081 variable 90082 90085 90080 90081 90003 T 90132 max 90133 [Nm] 90004 90082 90081 190 90082 90085 90080 90081 90003 N 90132 Tmax 90133 [rpm] 90004 90082 90081 4500 90082 90085 90080 90081 90003 P 90132 max 90133 [ HP] 90004 90082 90081 155 90082 90085 90080 90081 90003 N 90132 Pmax 90133 [rpm] 90004 90082 90081 6000 90082 90085 9008 0 90081 90003 N 90132 max 90133 [rpm] 90004 90082 90081 6800 90082 90085 90098 90099 90012 Saab 2.0T engine torque and power at full load 90013 90078 90079 90080 90081 90003 Cylinders architecture 90004 90082 90081 4 in-line 90082 91111 90002 Image: Saab 2.0T SI engine — torque and power curves at full load 90009 90082 90085 90080 90081 90003 Fuel 90004 90082 90081 gasoline (SI) 90082 90085 90080 90081 90003 Engine capacity [cm 90139 3 90140] 90004 90082 90081 1998 90082 90085 90080 90081 90003 Fuel injection 90004 90082 90081 valve port 90082 90085 90080 90081 90003 Air intake 90004 90082 90081 turbocharged 90082 90085 90080 90081 90003 Valve timing 90004 90082 90081 fixed 90082 90085 90080 90081 90003 T 90132 max 90133 [Nm] 90004 90082 90081 265 90082 90085 90080 90081 90003 N 90132 Tmax 90133 [rpm] 90004 90082 90081 2500 90082 90085 90080 90081 90003 P 90132 max 90133 [HP] 90004 90082 90081 175 90082 90085 90080 90081 90003 N 90132 Pmax 90133 [rpm] 90004 90082 90081 5500 90082 90085 90080 90081 90003 N 9013 2 max 90133 [rpm] 90004 90082 90081 6300 90082 90085 90098 90099 90012 Audi 2.0 TFSI engine torque and power at full load 90013 90078 90079 90080 90081 90003 Cylinders architecture 90004 90082 90081 4 in-line 90082 91111 90002 Image: Audi 2.0 TFSI SI engine — torque and power curves at full load 90009 90082 90085 90080 90081 90003 Fuel 90004 90082 90081 gasoline (SI) 90082 90085 90080 90081 90003 Engine capacity [cm 90139 3 90140] 90004 90082 90081 1994 90082 90085 90080 90081 90003 Fuel injection 90004 90082 90081 direct 90082 90085 90080 90081 90003 Air intake 90004 90082 90081 turbocharged 90082 90085 90080 90081 90003 Valve timing 90004 90082 90081 fixed 90082 90085 90080 90081 90003 T 90132 max 90133 [Nm] 90004 90082 90081 280 90082 90085 90080 90081 90003 N 90132 Tmax 90133 [rpm] 90004 90082 90081 1800 — 5000 90082 90085 90080 90081 90003 P 90132 max 90133 [ HP] 90004 90082 90081 200 90082 90085 90080 90081 90003 N 90132 Pmax 90133 [rpm] 90004 90082 90081 5100 — 6000 90082 90085 90080 9 0081 90003 N 90132 max 90133 [rpm] 90004 90082 90081 6500 90082 90085 90098 90099 90012 Toyota 2.0 D-4D engine torque and power at full load 90013 90078 90079 90080 90081 90003 Cylinders architecture 90004 90082 90081 4 in-line 90082 91111 90002 Image: Toyota 2.0 CI engine — torque and power curves at full load 90009 90082 90085 90080 90081 90003 Fuel 90004 90082 90081 diesel (CI) 90082 90085 90080 90081 90003 Engine capacity [cm 90139 3 90140] 90004 90082 90081 1998 90082 90085 90080 90081 90003 Fuel injection 90004 90082 90081 direct 90082 90085 90080 90081 90003 Air intake 90004 90082 90081 turbocharged 90082 90085 90080 90081 90003 Valve timing 90004 90082 90081 fixed 90082 90085 90080 90081 90003 T 90132 max 90133 [Nm] 90004 90082 90081 300 90082 90085 90080 90081 90003 N 90132 Tmax 90133 [rpm] 90004 90082 90081 2000 — 2800 90082 90085 90080 90081 90003 P 90132 max 90133 [HP] 90004 90082 90081 126 90082 90085 90080 90081 90003 N 90132 Pmax 90133 [rpm] 90004 90082 90081 3600 90082 90085 90080 90081 90003 N 90132 max 90133 [rpm] 90004 90082 90081 5200 90082 90085 90098 90099 90012 Mercedes-Benz 1.8 Kompressor engine torque and power at full load 90013 90078 90079 90080 90081 90003 Cylinders architecture 90004 90082 90081 4 in-line 90082 91111 90002 Image: Mercedes Benz 1.8 Kompressor SI engine — torque and power curves at full load 90009 90082 90085 90080 90081 90003 Fuel 90004 90082 90081 gasoline 90082 90085 90080 90081 90003 Engine capacity [cm 90139 3 90140] 90004 90082 90081 1796 90082 90085 90080 90081 90003 Fuel injection 90004 90082 90081 valve port 90082 90085 90080 90081 90003 Air intake 90004 90082 90081 supercharged 90082 90085 90080 90081 90003 Valve timing 90004 90082 90081 fixed 90082 90085 90080 90081 90003 T 90132 max 90133 [Nm] 90004 90082 90081 230 90082 90085 90080 90081 90003 N 90132 Tmax 90133 [rpm] 90004 90082 90081 2800 — 4600 90082 90085 90080 90081 90003 P 90132 max 90133 [HP ] 90004 90082 90081 156 90082 90085 90080 90081 90003 N 90132 Pmax 90133 [rpm] 90004 90082 90081 5200 90082 90 085 90080 90081 90003 N 90132 max 90133 [rpm] 90004 90082 90081 6250 90082 90085 90098 90099 90012 BMW 3.0 TwinTurbo engine torque and power at full load 90013 90078 90079 90080 90081 90003 Cylinders architecture 90004 90082 90081 6 in-line 90082 91111 90002 Image: BMW 3.0 TwinTurbo SI engine — torque and power curves at full load 90009 90082 90085 90080 90081 90003 Fuel 90004 90082 90081 gasoline 90082 90085 90080 90081 90003 Engine capacity [cm 90139 3 90140] 90004 90082 90081 2979 90082 90085 90080 90081 90003 Fuel injection 90004 90082 90081 direct 90082 90085 90080 90081 90003 Air intake 90004 90082 90081 dual-stage 90120 turbocharged 90082 90085 90080 90081 90003 Valve timing 90004 90082 90081 variable 90082 90085 90080 90081 90003 T 90132 max 90133 [Nm] 90004 90082 90081 400 90082 90085 90080 90081 90003 N 90132 Tmax 90133 [rpm] 90004 90082 90081 1300 — 5000 90082 90085 90080 90081 90003 P 90132 max 90133 [HP] 90004 90082 90081 306 90082 90085 90080 90081 90003 N 90132 Pmax 90133 [rpm] 90004 90082 90081 5800 90082 90085 90080 90081 90003 N 90132 max 90133 [rpm] 90004 90082 90081 7000 90082 90085 90098 90099 90012 Mazda 2.6 rotary engine torque and power at full load 90013 90078 90079 90080 90081 90003 Cylinders architecture 90004 90082 90081 2 Wankel 90082 91111 90002 Image: Mazda 2.6 SI engine — torque and power curves at full load 90009 90082 90085 90080 90081 90003 Fuel 90004 90082 90081 gasoline 90082 90085 90080 90081 90003 Engine capacity [cm 90139 3 90140] 90004 90082 90081 1308 (2616) 90082 90085 90080 90081 90003 Fuel injection 90004 90082 90081 valve port 90082 90085 90080 90081 90003 Air intake 90004 90082 90081 atmospheric 90082 90085 90080 90081 90003 Valve timing 90004 90082 90081 fixed 90082 90085 90080 90081 90003 T 90132 max 90133 [Nm] 90004 90082 90081 211 90082 90085 90080 90081 90003 N 90132 Tmax 90133 [rpm] 90004 90082 90081 5500 90082 90085 90080 90081 90003 P 90132 max 90133 [HP] 90004 90082 90081 231 90082 90085 90080 90081 90003 N 90132 Pmax 90133 [rpm] 90004 90082 90081 8200 90082 90085 90080 90081 90003 N 90132 max 90133 [rpm] 90004 90082 90081 9500 90082 90085 90098 90099 90012 Porsche 3.6 engine torque and power at full load 90013 90078 90079 90080 90081 90003 Cylinders architecture 90004 90082 90081 6 flat 90082 91111 90002 Image: Porsche 3.6 SI engine — torque and power curves at full load 90009 90082 90085 90080 90081 90003 Fuel 90004 90082 90081 gasoline 90082 90085 90080 90081 90003 Engine capacity [cm 90139 3 90140] 90004 90082 90081 3600 90082 90085 90080 90081 90003 Fuel injection 90004 90082 90081 valve port 90082 90085 90080 90081 90003 Air intake 90004 90082 90081 atmospheric 90082 90085 90080 90081 90003 Valve timing 90004 90082 90081 variable 90082 90085 90080 90081 90003 T 90132 max 90133 [Nm] 90004 90082 90081 405 90082 90085 90080 90081 90003 N 90132 Tmax 90133 [rpm] 90004 90082 90081 5500 90082 90085 90080 90081 90003 P 90132 max 90133 [HP] 90004 90082 90081 415 90082 90085 90080 90081 90003 N 90132 Pmax 90133 [rpm] 90004 90082 90081 7600 90082 90085 90080 90081 90003 N 90132 max 90133 [rpm] 90004 90082 90081 8400 90082 90085 90098 90099 90002 Key statements to keep in mind regarding engine power and torque: 90009 90002 90003 Torque 90004 90009 91987 91988 torque is a component of power 91989 91988 torque can be increased by increasing the mean effective pressure of the engine or by lowering the torque losses (friction, pumping) 91989 91988 having a lower maximum torque distributed on a range of engine speeds its better from the traction point of view than having a higher maximum torque point 91989 91988 low end torque is very important for the launch capabilities of the vehicles 91989 91988 high torque is beneficial in off-road situation, when the vehicle is operated at high road gradients but low speed 91989 91998 90002 90003 Power 90004 90009 91987 91988 engine power depends on both torque and speed 91989 91988 power can be increased by increasing the torque or the engine speed 91989 91988 high power is important for high vehicle spe eds, the higher the maximum power the higher the maximum speed of the vehicle 91989 91988 engine power distribution at full load, through the engine speed range, affects the acceleration capability of the vehicle at high speeds 91989 91988 for best acceleration performance, a vehicle should be operated in the power band, between maximum engine torque and power 91989 91998 90002 For any questions or observations regarding this tutorial please use the comment form below.90009 90002 Do not forget to Like, Share and Subscribe! 90009.90000 Torque OBD 2 engine diagnostics — Torque 90001 90002 90003 90003 Torque is an engine diagnostics application for Android that allows you to directly monitor your car engine control unit (ECU) and retrieve various information from the sensors connected to it as well as use your phones internal GPS and accelerometer sensors to graph other information such as acceleration 90005 90002 Torque can be used to view any stored fault codes on your vehicles ECU, then, after a mechanic fixing the fault, it also can clear the fault codes allowing you to clear the ‘Check Engine’ light warning on your dashboard 90005 90002 Torque can use a multitude of OBD adapters, ranging from the cheap (and slightly buggy) adapters you can find on ebay, to the more reliable 90005 90002 Scantool.net’s OBDLink series of adapters, PLX Devices Kiwi Bluetooth, ScanTool.net’s bluetooth adapter andOBDKey which are the amongst the most reliable. 90005 90002 The adapters are used to interface your Android device to the vehicle engine control unit (ECU). 90005 90002 90003 90016 OBDLink MX, pictured above — one of the fastest and most compact adapters from scantool.net 90017 90005 90002 90003 90016 Kiwi Bluetooth, pictured above — a good adapter from PLX devices 90017 90005 90002 90003 90016 Generic bluetooth adapter from ebay, generally alright but some can suffer from build quality issues affecting reliability, and causing strange things to happen like engines refusing to start.Try to avoid if you can 90017 90005 90002 90003 90016 PLX devices kiwi Wi-Fi OBD, good but you have to hack your phone for root access, the recently announced PLX Kiwi Bluetooth adapter is preferred as no modifications are required. 90017 90005 90002 Torque can be downloaded from the Android market ad free, or you can try the ad-supported version. Torque works on android 1.5 / 1.6 / 2.0 / 2.1 or above! 90005 90002 The change log and version history for Torque can be viewed by clicking here.90005 90002 Any car manufacturered from 2000 onwards (and quite a few from the mid ’90s) should have an OBD2 compliant diagnostics port installed. Check your manual or google if you are unsure if yours has one or where it is — some ports are hidden quite well under ashtrays, etc. 90005 90002 Torque can also upload in realtime data to the Torque viewer website so that you can view your recorded OBD data online 90005 90002 Some screenshots from Torque for Android are shown below (Click the image for full size view) 90003 90005 90002 There is now a forum available to discuss Torque! 90005 .90000 How to Measure the Torque (Twisting Power) of Your Car 90001 90002 Whether you’re buying a new car or building a hot rod in your garage, two factors come into play when determining engine performance: horsepower and torque. If you’re like most DIY mechanics or automotive enthusiasts, you probably have a good understanding of the relationship between horsepower and torque, but may struggle on comprehending how those «foot pound» numbers are achieved. Believe it or not, it’s really not that complex.90003 90002 Before we get too technical, let’s break down some simple facts and definitions that make it easier to comprehend why both horsepower and torque are important factors to consider. We should begin by defining the three elements of measuring performance of a combustion engine: speed, torque and horsepower. 90003 90006 Part 1 of 4: Understanding how engine speed, torque, and horsepower impact overall performance 90007 90002 In a recent Hot Rod magazine article, one of the greatest mysteries in engine performance was finally figured out by getting back to basics of how horsepower is actually factored.Most people assume that dynometers (engine dynos) are designed to measure the horsepower of an engine. 90003 90002 In reality, dynometers do not measure horsepower, they measure torque. That torque figure is multiplied by the RPM it is measured at and then divided by 5,252 to produce a horsepower figure. 90003 90002 For more than 50 years, the dynometers used to measure torque and engine RPM simply could not handle the intense power produced by these engines. In fact, one cylinder on these 500 cubic inch displacement, nitromethane burning Hemis produces an estimated 800 pounds of thrust through a single exhaust pipe.90003 90002 All engines, whether combustion or electrically powered, operate at different speeds. For the most part, the faster an engine completes its power stroke or cycle, the more power it produces. In regards to a combustion engine, the three elements that impact the overall performance of that engine are speed, torque and horsepower. 90003 90002 Speed ​​is defined as how fast the motor performs its work. When we apply the speed of the engine to a number or a unit of measurement, we gauge the engine’s speed in revolutions per minute or RPM.The «work» that the engine performs is a force applied over a measured distance. Torque is defined as a special type of work that produces rotation. This occurs when a force acts on a radius (or, for a combustion engine, the flywheel) and is typically measured in foot pounds. 90003 90002 Horsepower is the rate at which work is accomplished. Back in the old days, if objects needed to be moved, humans typically used a horse to move it. It was estimated that one horse could move approximately 33,000 foot pounds per minute.This is where the term «horsepower» originates. Different from speed, and torque, horsepower can be measured in multiple units including: 1 HP = 746 Watts, 1 HP = 2,545 BTUs, and 1 HP = 1,055 joules. 90003 90002 These three elements work together to produce engine power. As torque remains constant, speed and horsepower remain proportional. However, as the engine’s speed increases, the horsepower also increases in order to maintain constant torque. Where many people get confused, however, is in how torque and horsepower impact the engine’s speed.Quite simply, as the torque and horsepower increase, so does the engine’s speed. The reverse is also true: when the torque and horsepower decrease, so does the engine’s speed. 90003 90006 Part 2 of 4: How engines are built to maximize torque 90007 90002 The modern combustion engine can be altered to enhance horsepower or torque by manipulating the size or length of the connecting rod and increasing the bore or diameter of the cylinder. This is often referred to as the bore / stroke ratio. 90003 90002 Torque is measured in Newton meters.In simple terms, this means that torque is measured in a 360-degree circular motion. Our example takes two identical motors that have the same sized bore (or the diameter of the combustion cylinder). However, one of the two motors has a longer «stroke» (or the depth of the cylinder as produced by a longer connecting rod). The motor with the longer stroke has more straight motion while it rotates through the combustion chamber and has more leverage to accomplish the same task. 90003 90002 Torque is measured in pound-feet or how much «twisting force» is applied to complete a task.For example, imagine you’re trying to loosen a rusty bolt. Let’s assume you have two different pipe wrenches, one is 2 ‘long, the other is 1’ long. Assuming you apply the same amount of force (in this case 50 pounds of pressure) you are actually applying 100 foot pounds of torque for the two foot wrench (50 x 2) and only 50 lbs. of torque (1 x 50) with the one foot wrench. Which wrench will help you loosen the bolt easier? The answer is easy — the one with more torque. 90003 90002 Engineers develop an engine to produce a higher torque to horsepower ratio for vehicles that need the extra «power» for acceleration or for climbing.Typically, you see higher torque ratings for heavy duty trucks used for towing applications or high performance engines where acceleration is critical (such as the NHRA Top Fuel Engine example noted above). 90003 90002 This is why automotive manufacturers often highlight the high torque potential of engines in truck commercials. Engine torque can also be amplified by changing ignition timing, adjusting air to fuel mixtures, and even manipulated to increase torque output during certain scenarios.90003 90006 Part 3 of 4: Understanding other variables that impact overall torque rating of an engine 90007 90002 When it comes to measuring the torque, there are three unique variables within the combustion engine that you must consider: 90003 90002 The force created at a specific RPM: This is the max horsepower of the engine produced at a desired RPM. When an engine accelerates, there is an RPM or horsepower curve. As the engine RPM increases, the horsepower increases as well, until it reaches a maximum level.90003 90002 The distance: This is the length of the connecting rod stroke: the longer the stroke, the more torque is created as we explained above. 90003 90002 The constant of the torque: This is a mathematical number that is assigned to all engines, 5252 or the constant RPM where the horsepower and torque are balanced. The number 5252 was derived from the observation that one horsepower was equivalent to 150 pounds which covered 220 feet in one minute. To express this in foot pounds of torque, a mathematical formula was introduced by James Watt, who invented the first steam engine.90003 90002 The formula is as follows: 90003 90002 Assuming the force of 150 pounds is applied to one foot of a radius (or circle that’s found inside a combustion engine’s cylinder, for example) you’d have to convert this to foot pounds of torque. 90003 90002 220 feet in one minute needs to be extrapolated into revolutions per minute. To do this, you’d take two times Pi (or 3.141593) which equals 6.283186 feet. Take 220 feet and divide by 6.28 and we get an RPM of 35.014 for each revolution.90003 90002 Take the 150 feet and multiply times 35.014 and you get 5252.1 — which is our constant that is factored into measuring foot pounds of torque. 90003 90006 Part 4 of 4: How to calculate the torque of a vehicle 90007 90002 The formula for figuring out torque is torque = horsepower of the engine x 5252, which is then divided by the RPMs. 90003 90002 The problem with torque, however, is that it is measured in two different places: directly from the engine and to the drive wheels.Other mechanical components than can increase or decrease torque ratings to the wheels include: flywheel size, transmission gear ratios, drive axle gear ratios, and tire / wheel circumference. 90003 90002 In order to figure out the torque to the wheel, all of these items must be factored into the equation, which is best left to a computerized program included in a performance dyno. On this type of equipment, the car is placed on a rack and the drive tires are placed next to a series of rollers.The engine is plugged into a computer read out that monitors engine RPM, fuel curve, and gear ratios. These numbers are factored with wheel speed, acceleration and shift RPM’s as the vehicle is driven on the dyno for a desired length of time. 90003 90002 The calculation of torque of the engine is a lot easier to determine. Following the formula above, it’s clear to see how the torque of the engine is proportional to the horsepower and the engines ‘RPM as explained in the first section. By using this formula, you can figure out the torque and horsepower ratings at each point of the RPM curve.You need to have the engine’s horsepower figures which are produced by the engine manufacturer in order to calculate the torque. 90003 Torque calculator 90002 Some people utilize an online calculator, offered by MeasureSpeed.com that requires you input the engine’s max horsepower ratings (supplied by the manufacturer or completed during a professional engine dyno pull) and the desired RPM. 90003 90002 If you notice that your engine performance struggles to accelerate and does not have the power you think it should, have one of YourMechanic’s certified mechanics perform an inspection to determine the source of the issue.90003 .