**What is Torque?**

In simple words **Torque** is defined as a **Force** around a given point, applied at a **radius **from that point. It can be described also as the tendency of a** Force **to rotate an object about an axis,

or more freely speaking , as a measure of the turning **Force** on an object . In our case that object is the engine's crankshaft. **Torque** is a dimensional concept, it has dimensions of **Force** times **Distance.**

**Torque = Force x Radius**

The concept of **Torque**, also called **Moment** or **Couple**, originated with the studies of Archimedes on levers. The rotational analogues of **Force**, **Mass**, and **Acceleration** are **Torque**, **Moment of Inertia** and **Angular Acceleration**, respectively.

**T****orque** is defined mathematically as the **rate of change of Angular Momentum of an object**.

Take your time to observe this animation it will really help you visualize the terms

*Relationship between*** Force F (blue)**, **Torque τ (violet)**, **Linear Momentum p (dark green)**, and **Angular Momentum L (light green**) in a system which has rotation constrained in one plane only (forces and moments due to gravity and friction not considered).

Popular Torque units are **lbf.ft** (**pound-force foot** or **pound foot** for short) **N.m** (**Newton meter**) **kgf.m** (**kilogram force meter**) (you see that **“force”** popup after pound or kilogram, so they are not confused with plain pound or kilogram which are mass units, not force units)

*****Also be aware that **"foot pound" ft.lb** is a unit of **Energy** or **Work** ,**not Torque **. So when working with formulas and units, be careful not to mix them up. This can be confusing since some times we use **"foot pound"** for "**pound foot" **see the table below:

**International Torque Measuring Systems**

**American**

ozf.in - ounce force inch (referred as inch-ounces*****)

**lbf.in** - pound force inch (referred as inch-pounds*****)

**lbf.ft** - pound force foot (referred as foot-pounds*****)

**International Standard - S.I.**

mN.m - milli Newton meter

**cN.m - **centi- Newton meter

**N.m - **Newton meter

**Metric**

gf.cm - gram force centimeter

**kgf.cm - **kilogram force centimeter

**kgf.m - **kilogram force meter

as we see according to **SI (The International System of Units)** the suggested

torque unit is **N.m or Nm**

The symbol for torque is typically**τ**, the Greek letter “tau*”)*.

**In GT6 to my Knowledge N.m (as Nm), kgf.m (as kgfm), lbf.ft (as ft-lb) units are used depending on language set.**

as we see PD is using ft-lb instead of lbf.ft or lb.ft which is as discussed above*

although technically(in math and physics or engineering) not correct,

used also in everyday life.

see here and here
**If your game setup uses another unit,**
**please inform me so I can add it here**
**1 N.m = 0.101971621298 kgf.m = 0.737562149 lbf.ft**

1 kgf.m = 7.23301385121 lbf.ft = 9.80665 N.m

1 lbf.ft = 0.138254954376 kgf.m = 1.35581794833 N.m

**What is Rotational speed? **

**Rotational speed **of a mechanical component(sometimes called **revolution speed or rotational frequency**) is expressed as the number of complete rotations, revolutions, cycles, or turns per time unit. In our case its the number of complete revolutions the engine's crankshaft does in a minute, hence **RPM**.

**Revolutions per minute** (abbreviated **rpm**, **RPM**, **r/min**, or **r·min-***¹*) is a measure of the Frequency of a rotation. It annotates the number of turns completed in one minute around a fixed axis. It is widely used as the rotational speed Unit although its not considered as a Unit by the** SI** which suggests **s-****¹** or **Hz ***(Hertz - cycles per second) which is the equivalent of ***rps** (revolutions per second) .

When using **Angular speed**, **rad·s-¹ **(*radians per second) are* used as units*. ***Angular speed **differs from **Rotational speed** in the fact that it represents the change in angle per time unit* and can do so for any angle rate not only*** 2π.rad** which is 1 full revolution.

*An arc of a circle with the same length as the radius of that circle corresponds to an angle of 1 radian. A full circle corresponds to an angle of 2π radians. *

The symbol for rotational speed according to** SI** is **f** , although** ω** (the Greek lowercase letter "omega" used for Angular speed) is also widely used.

**What is Power?**

**Power** is the measure of how much** work** can be done in a specified **time** ,or in other words, the **rate of work **produced. in our case by the car's engine.

**Power = Force x Distance per minute (for linear motion)**

In order to understand power better, you need to understand the concept of **Work**:

**Work **is defined as a** Force **operating through a **Distance**. If you try to push a wall with all your strength for say 5 minutes , you will be exhausted and sweaty but you will have produced **no Work**. Although you have been exerting a **Force** on the wall, the wall didn't move, there was no motion, so there was no **Work **produced.

On the other hand if you were pushing your car exerting a constant force of 100 pounds (in the exact direction the car is traveling on a flat friction-less level surface ) moving it for a distance of 200 feet in 2 minutes, you will have had produced :100 pounds of force*200 feet of distance=**20,000 foot-pounds of Work in 2 minutes, or 10,000 foot-pounds of Work per minute.**

**Work = Force x Distance**

So going back to the Power formula:** Power = Force x Distance per minute **and substituting we get:

**Power = Work per minute**

**so for the above example the power you produced to move your car is:**

**Power = 10.000 foot-pounds per minute**

**By definition 1HP = 33.000 foot-pounds of Work per minute, so the above becomes:**

**HP = 10,000 ÷ 33,000 = 0,303**

**So all that hassle and pain for less than a third of a Horse Power?**

*a healthy human can produce about 1.2 hp briefly and sustain about 0.1 hp indefinitely; trained athletes can manage up to about 2.5 hp briefly and 0.3 hp for a period of several hours.*

Popular Power units are **HP** (*Horse power*) **BHP** (*Brake Horse Power*) **KW** (*KilloWatt)***CV** (*cavalli vapore *and *chevaux vapeur *which mean steam horses in Italian and French) **PS** (*Pferdestärke* which means horse strength in German)

According to SI (The International System of Units) the suggested Power unit is the **W (Watt) , KW=1000W**

**In GT6 to my Knowledge HP BHP KW CV are used depending on language set.**

**If your game setup uses another unit,**

**please inform me so I can add it here**

**1 HP (metric)=0.98632 BHP (international-Imperial HP)=0.73549875 KW=1 CV=1 PS**

**OK with all that... What is their relation in an engine. Why should I care?**

**Power , Torque and RPM are brothers. Actualy Torque and RPM are the young twins, while Power is their older brother. Together they make an engine work. If one of the twins is missing, no game.**

**Something to remember is that Torque and RPM are the measured quantities of an engines output.**

**Power can only be calculated from Torque and RPM, and cannot be directly measured.**

**Power is Torque and RPM dependent .**

**Power produced from an engine is not a fixed figure as many people believe, it varies with RPM and Torque, the quantities from which it derives. Torque itself varies with RPM too.**

**So when somebody brags and says “my car has 300 HP ” he should mean “my car has a maximum power output of 300 HP at 5800 RPM” if he knew his cars data that is. What he doesn't know though is that his car probably has around 100 HP at around 2000 RPM ... not 300 HP.**

**Another interesting thing is that he doesn't care or know what his engines Torque is, or at what RPM its maximum value occurs... Why should he care? **

**He should care if somebody he brags about his 300 HP comes along with his 280 HP car, and trashes him on a road race between traffic lights...**

**Why would that happen? The 2 cars have the same weight, same gearboxes,same tyres...just the engine is different...**

**That's because the 280 HP car had more maximum Torque and it occurred at a lower RPM than the 300 HP car. That makes the 280 HP car go faster than the 300 HP car between the traffic lights.**

**Rings a bell? It should if your trying to tune your cars engine in GT 6 , for a fixed PP **

Seasonal Time Trial...

**The formula that governs the Power, Torque, and Rotational speed relationship, in an engine is:**

**Power = Torque x 2***π x*Rotational Speed = Torque x Angular Speed

** HP = ****lbf.ft** x RPM ÷ 5252

*The formula above applies when torque is in pound-foot units ***lbf.ft**, rotational speed is in **RPM** (revolutions per minute) and power is required in imperial horsepower **HP .( 5252 is a constant that changes depending on units used.)**

**W = Nm x 2***π x rps*

*The above formula applies when ***SI** Units are used: Power is in **Watts**, Torque is in **Nm** (Newton meters) and Rotational Speed is in **RPS** (Revolutions per second). **π **is a constant that is the ratio of a circle's circumference to its diameter and is approximately equal to **3.14159.**

enough for now, I think I need a break!

I'll just end this first section with something I find very true:

**Carroll Shelby** and** Enzo Ferrari** once said: **“Horsepower sells cars, torque wins races.**