The Torque Thread. And other little things you might find useful...

Discussion in 'GT6 Tuning' started by yannagas, Mar 7, 2014.

  1. yannagas

    yannagas

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    As the tittle suggests this Thread is about Torque, Power's mighty little brother, that seems to be in it's older brother's shade...at least for many players of this game.

    But not only that.

    This is where I will attempt to post answers to some tech oriented questions that I find on my way through this game, and cant' find in the game's manual, or elsewhere..

    It's where some of my experiments will be posted, my findings and such trivial stuff...

    Index:

    Part1. The basics of Torque , Rotational speed, Power and how they are connected.
    Part2. Measuring Power, Designing an engine, BMEP, and an interesting F1-NASCAR engine comparison.
    Part3. Car and Engine Performance in Real life vs GT-6

    Experiments and finds:

    Oil related:

    Part1. Oil change boost effect on Torque
    Part2. Oil change boost effect on Torque (Tuned Cars)
    Part3. Oil change boost effect on Torque (Power Limiter)
    Part4. Oil change boost deterioration effect on Torque

    The GT-6 Tuning blocks evaluated:
    The hidden Power of the Power Limiter (New)

    Other:
    PD's reporting error The "Schizo" effect

    This thread will be continuously updated with new stuff, So check back often!
     
    Last edited: Mar 25, 2014
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  2. yannagas

    yannagas

    Messages:
    281
    Location:
    Greece
    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.


    Torque is defined mathematically as the rate of change of Angular Momentum of an object.


    Torque_animation.gif

    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 typicallyτ, 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.



    300px1-Circle_radians.gif

    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 2π xRotational 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 2π 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.
     
    Last edited: Mar 27, 2014
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  3. yannagas

    yannagas

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    Measuring Power

    A dynamometer determines the POWER an engine produces by applying a load to the engine output shaft by means of a water brake, a generator, an eddy-current absorber, or any other controllable device capable of absorbing power. The dynamometer control system causes the absorber to exactly match the amount of TORQUEthe engine is producing at that instant, then measures that TORQUE and the RPM of the engine shaft, and from those two measurements, it calculates observed power. Then it applies various factors (air temperature, barometric pressure, relative humidity) in order to correct the observed power to the value it would have been if it had been measured at standard atmospheric conditions, called corrected power.


    Designing an engine


    In order to design an engine for a particular application, it is helpful to plot out the optimal power curve for that specific application, then from that design information, determine the torque curve which is required to produce the desired power curve. By evaluating the torque requirements against realistic BMEP values you can determine the reasonableness of the target power curve. SEE BMEP FURTHER DOWN THE PAGE

    Typically, the torque peak will occur at a substantially lower RPM than the power peak. The reason is that, in general, the torque curve does not drop off (%-wise) as rapidly as the RPM is increasing (%-wise). For a race engine, it is often beneficial ( within the boundary conditions of the application ) to operate the engine well beyond the power peak, in order to produce the maximum average power within a required RPM band.

    However, for an engine which operates in a relatively narrow RPM band, such as an aircraft engine, it is generally a requirement that the engine produce maximum power at the maximum RPM. That requires the torque peak to be fairly close to the maximum RPM. For an aircraft engine, you typically design the torque curve to peak at the normal cruise setting and stay flat up to maximum RPM. That positioning of the torque curve would allow the engine to produce significantly more power if it could operate at a higher RPM, but the goal is to optimize the performance within the operating range.

    An example of that concept is shown Figure 3 below. The three dashed lines represent three different torque curves, each having exactly the same shape and torque values, but with the peak torque values located at different RPM values. The solid lines show the power produced by the torque curves of the same color.

    [​IMG]

    Figure 3


    Note that, with a torque peak of 587 lb-ft at 3000 RPM, the pink power line peaks at about 375 HP between 3500 and 3750 RPM. With the same torque curve moved to the right by 1500 RPM (black, 587 lb-ft torque peak at 4500 RPM), the peak power jumps to about 535 HP at 5000 RPM. Again, moving the same torque curve to the right another 1500 RPM (blue, 587 lb-ft torque peak at 6000 RPM) causes the power to peak at about 696 HP at 6500 RPM

    Using the black curves as an example, note that the engine produces 500 HP at both 4500 and 5400 RPM, which means the engine can do the same amount of work per unit time (power) at 4500 as it can at 5400. HOWEVER, it will burn less fuel to produce 450 HP at 4500 RPM than at 5400 RPM, because the parasitic power losses (power consumed to turn the crankshaft, reciprocating components, valvetrain) increases as the square of the crankshaft speed.

    The RPM band within which the engine produces its peak torque is limited. You can tailor an engine to have a high peak torque with a very narrow band, or a lower peak torque value over a wider band. Those characteristics are usually dictated by the parameters of the application for which the engine is intended.

    An example of that is shown in Figure 4 below. It is the same as the graph in Figure 3 (above), EXCEPT, the blue torque curve has been altered (as shown by the green line) so that it doesn't drop off as quickly. Note how that causes the green power line to increase well beyond the torque peak. That sort of a change to the torque curve can be achieved by altering various key components, including (but not limited to) cam lobe profiles, cam lobe separation, intake and/or exhaust runner length, intake and/or exhaust runner cross section. Alterations intended to broaden the torque peak will inevitable reduce the peak torque value, but the desirability of a given change is determined by the application.


    [​IMG]

    Figure 4



    BMEP


    Brake Mean Effective Pressure (BMEP) is another very effective yardstick for comparing the performance of an engine of a given type to another of the same type, and for evaluating the reasonableness of performance claims or requirements.

    The definition of BMEP is: the average (mean) pressure which, if imposed on the pistons uniformly from the top to the bottom of each power stroke, would produce the measured (brake) power output.

    Note that BMEP is purely theoretical and has nothing to do with actual cylinder pressures. It is simply a tool to evaluate the efficiency of a given engine at producing torque from a given displacement.

    A torque output of 1.0 lb-ft per cubic inch of displacement in a 4-stroke engine equals a BMEP of 150.8 psi. In a 2-stroke engine, that same 1.0 lb-ft of torque per cubic inch is a BMEP of 75.4 psi.

    By looking at equations 8-a and 8-b below, you can easily see that BMEP is simply the torque per cubic inch of displacement, multiplied by a constant. In fact, many talented people in the engine design and developmeny business currently use torque-per-cubic inch ("torque ratio") instead of BMEP, thereby avoiding that tedious multiplication process.

    (The discussion on the remainder of this page is with respect to four-stroke engines, but it applies equally to two stroke engines if you simply substitute 75.4 everywhere you see 150.8)

    If you know the torque and displacement of an engine, a very practical way to calculate BMEP is:

    BMEP (psi) = 150.8 x TORQUE (lb-ft) / DISPLACEMENT (ci)

    (Equation 8-a, 4-Stroke Engine)

    BMEP (psi) = 75.4 x TORQUE (lb-ft) / DISPLACEMENT (ci)

    (Equation 8-b, 2-Stroke Engine)

    (IF you prefer pressure readings in Bar rather than PSI, simply divide PSI by 14.5)


    Using BMEP to compare F1 and NASCAR engines


    An F1 engine is purpose-built and essentially unrestricted. For 2006, the rules required a 90° V8 engine of 2.4 liters displacement (146.4 CID) with a maximum bore of 98mm (3.858) and a required bore spacing of 106.5 mm (4.193). The resulting stroke to achieve 2.4 liters is 39.75 mm (1.565) and is implemented with a 180° crankshaft. The typical rod length is approximately 4.016 (102 mm), for a Rod / Stroke ratio of about 2.57. These engines are typically a 4-valve-per cylinder layout with two overhead cams per bank, and pneumatic valvesprings. In addition to the few restrictions stated above, there are the following additional restrictions: (a) no beryllium compounds, (b) no MMC pistons, (c) no variable-length intake pipes, (d) one injector per cylinder, and (e) the requirement that one engine last for two race weekends.

    At the end of the 2006 season, most of these F1 engines ran up to 20,000 RPM in a race, and made in the vicinity of 750 HP. One engine for which I have the figures made 755 BHP at an astonishing 19,250 RPM. At a peak power of 755 HP, the torque is 206 lb-ft and peak-power BMEP would be 212 psi. (14.63 bar). Peak torque of 214 lb-ft occurred at 17,000 RPM for a BMEP of 220 psi (15.18 bar). There can be no argument that 212 psi at 19,250 RPM is truly amazing.

    However, let's look at some astounding domestic technology.

    The NASCAR CUP race engine is a severely-restricted powerplant, allegedly being derived from "production" components, although as of 2010, all 4 engines competing at that level (Chevy, Dodge, Ford, Totota) are purpose-built race engines designed specifically to NASCAR's rule book.

    By regulation, CUP engines have a maximum displacement of 358 CI (5.87 L). They must use a cast-iron 90° V8 block with a 4.500 inch bore spacing and a 90° steel crankshaft. A typical configuration has a 4.185" bore with a 3.25" stroke and a 6.20" conrod (R/S = 1.91). Cylinder heads are similarly purpose-designed and highly-developed, but limited to two valves per cylinder, specific valve angles, specific port floor heights, etc.. The valves are operated by a single, block-mounted, flat-tappet camshaft (that's right, still no rollers as of 2012) and a pushrod / rocker-arm / coil-spring valvetrain. It is further hobbled by the requirement for a single four-barrel carburetor (until 2011) and now (2012 on), by a 4-barrel-carburetor-like throttle body and individial runner EFI. Electronically-controlled ignition is allowed (as of 2012), and there are minimum weight requirements for the conrods and pistons.

    How does it perform? In early 2010, the engines were producing in the neighborhood of 860 HP at 9000 RPM, and they operate at a max race rpm in the vicinity of 9400 rpm. That max rpm is controlled by a NASCAR rule that specifies the final drive ratio at each track (the "gear rule"). If it were not for the gear rule, these engines would be operating at well over 10,000 rpm at the race track..

    Consider the fact that, to produce 860 HP at 9000 RPM, requires 501 lb-ft of torque, for a peak-power BMEP of nearly 211 PSI (14.55 bar). Peak torque (2010) was typically about 535 lb-ft at 7800 RPM, for a peak BMEP of over 226 psi (15.6 bar, torque ratio of 1.50).

    THAT is truly astonishing. Compare the F1 engine figures to the CUP engine figures for a better grip on just how clever these CUP engine guys are. In addition, consider the fact that (a) a single engine must be used for each race meeting, which includes at least two practice sessions, a qualifying session, and the race, which can be as long as 600 miles, and (b) the Penske-Dodge engines that won the 2012 championship did not suffer a single engine failure throughout the 2012 38-race season.

    That being said, recent winners in the annual Engine Masters competition are achieving over 16.9 bar BMEP (245 psi, torque ratio of 1.63 ! ) with normally-aspirated, petrol-fueled, SI, 2-valve pushrod engines, although the builders freely admit that, due to the very aggressive cam profiles, rocker ratios, gross valve lift numbers, and other compromises aimed at maximizing BMEP, these engines have relatively short life expectancies.

    To appreciate the value of this comparison tool, suppose someone offers to sell you a 2.8 liter (171 cubic inch) Ford V6 which allegedly makes 230 HP at 5000 RPM, and is equipped with the standard OEM iron heads and an aftermarket intake manifold and camshaft. You could evaluate the reasonableness of this claim by calculating (a) that 230 HP at 5000 RPM requires 242 lb-ft of torque (230 x 5252 ÷ 5000), and (b) that 242 lb-ft. of torque from 171 cubic inches requires a BMEP of 213 PSI (150.8 x 242 ÷ 171).

    You would then dismiss the claim as preposterous because you know that if a guy could do the magic required to make that kind of performance with the stock heads and intake design, he would be renowned as one of the pre-eminent engine gurus in the world. (You would later discover that the engine rating of "230" is actually "Blantonpower", not Horsepower.)



    the above is a compillation of articles selected and stiched from http://www.epi-eng.com/

    read the complete comparison article on F1 and NASCAR engines here
     
    Last edited: Mar 11, 2014
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  4. yannagas

    yannagas

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    CAR PERFORMANCE IN REAL LIFE vs GT-6


    CAR PERFORMANCE IN REAL LIFE


    By performance we mean the cars Acceleration, Speed, Braking, Cornering, Traction, Stability, and such abilities that could also include fuel efficiency, thermal efficiency, friction efficiency etc


    In Real life a cars performance depends on: Weight, Aerodynamics, Engine performance, Gearing, Drivetrain, Suspension, Brakes, Tyres, and environmental variables like Terrain, Temperature, Humidity, Wind, Elevation etc. So we could say that a Cars performance represents the sum of the above factors in a way that looks like this:


    Car Performance = Weight Performance + Aero Performance + Engine Performance
    + Gearing Performance + Drivetrain Performance + Suspension Performance
    + Brakes Performance + Tyres Performance


    Actually all of these sub-performances, are extremely complex on their own, each having many aspects of performance related qualities, quantities, subsystems and divisions,
    so it would be a joke to try to unite them in a single formula.

    In Addition to the above mentioned complexity, each of the environmental variables mentioned before, affect each of the above sub-performances in a different way, and may affect more than one (e.g. Temperature will affect the engine performance in a different way than the tyre performance e.t.c. ).

    In Real life there is no unit used to measure car performance as a whole, nor can somebody compare two different cars with just one value or number. But instead we can compare individual sub-performances, on a 1 on 1 basis.

    To further simplify the way we compare performance subsystems, and make things easier to use in formal talk, we have invented concepts like Grip, or Cornering or Kick for Acceleration etc, which are in a way unified groups of complex systems and subsystems, and make quick comparisons possible, however not always very clear and in most cases are closely related...

    i.e. Grip would include Weight and its distribution, Aerodynamics(the Down-force part),Suspension settings and drivetrain type,plus of-course Tyre performance. Then Grip used in that sense would affect Cornering, (and vice-versa), and so forth...



    CAR PERFORMANCE IN GT-6


    In GT-6 a cars performance is represented in PP (Performance Points) These are the units used in the game to compare 2 or more cars on a performance basis. Nobody Knows the formula from which PP figures derive, (except PD's programmers of-course), and anything I come up with, can only be a vague wild guess. However it should look something like the one I came up with for the real world.


    But wait, lets see what we know affects PP in the Game: Weight and its placement , Aero, and Engine performance are the ones I know of, mostly through tuning the cars for TT's.

    However these are the values we can change, and thats how we know they affect PP.

    There are values set for every car in the game by PD, and we can only change some of those.


    The manual states:

    Every car is a different weight, and boasts different levels of engine power. As a result, every car in Gran Turismo 6 has been given a PP (Performance Points) figure, which indicates its performance level. Cars which have similar PP figures are sure to enjoy a closely fought race - even if their body sizes and displacement levels are totally different.

    PP is determined by an overall analysis of the factors that affect a car's racing performance, such as engine power and weight. A car's PP figure will also change according to changes made in Car Settings which affect its max. power, max. torque or weight.

    The manual is very vague, and not very helpful...


    So further in this Thread I will try to investigate aspects of the story as much as possible.. Who knows? Maybe I find something interesting and helpful... maybe not... We'll see.




    THE ENGINE PERFORMANCE IN REAL LIFE vs GT-6


    ENGINE PERFORMANCE IN REAL LIFE


    In Real life an engines performance depends on its Power and Torque values and rotational capability and characteristics ( Toque curve, Power curve), and its efficiency (fuel, thermal, volumetric e.t.c.),

    as well as it's physical dimensions, size and weight. i.e. it's design properties.

    Different engines are designed for different purposes, with different target performance curves and efficiency levels. Please see the discussion in part.2

    As we already showed in part.1 , Power Torque and rotational speed , are closely tied together.

    The engine converts chemical energy into Torque, that Accelerates the spinning (rotation) of the crankshaft through a range of RPM .The Torque is measured in that entire range of RPM, and is plotted on a graph. The Power is a calculated product of the Torque at a certain Rotational speed , and using the Toque graph, a Power graph is calculated. These two graphs are then combined into a single graph.
    This is the engines performance ID card. Looking at such a graph will tell you all you need to know about how an engine behaves and performs throughout its rotational speed range.



    4.2FSI 3.2FSI GRAPH.png

    These two real life graphs show how Audi's 4.2 FSI and 3.2 FSI engines compare. Note that Torque and RPM scale is the same on both graphs and thus Torque can be visually compared correctly between engines. However the Power output scale is different, and direct visual comparison can't be made.
    This means you cannot superimpose the two graphs for Power comparison, But you can for Torque.

    In order to quickly compare the Power curves in this case, because the RPM scale is the same, and Power scale is close, you need to move the 3.2 FSI Power curve onto the 4.2 FSI graph, and place it so its starting and ending points match the new scale as possible. However the correct method would be to re-plot the 3.2 FSI Power curve, on the 4.2 FSI graph. This would generate a new curve with a new shape, and would make the visual comparison accurate and correct.


    Basic Factors that influence Torque, Power and Rotational ability-speed in an engine are:


    Volumetric characteristics such as: the Displacement (Bore x Stroke) of the engine, which has a direct influence on its Torque capacity.

    This factor affects the volume of the fuel-air mixture that can fill the cylinder and be converted to Torque during the power cycle , either in a natural, or forced way.

    In NA (Naturally Aspirated) engines as the name shows, Displacement plays a great role, since the volume of the fuel-air mixture sucked in the cylinder by the vacuum created by the piston area (bore) travelling down (stroke), is largely dictated by it, among other factors like Intake and Exhaust factors.

    In FI (Forced Induction) engines such as Supercharged or Turbocharged, Displacement can be significantly smaller, since the amount of fuel-air mixture that gets forced and compressed to fill the cylinder volume, is greatly larger than in NA engines. However although a larger piston area will always deliver the combustion energy to the crankshaft in an easier way, a smaller piston has less mass , less inertia and less friction. A smaller stroke will make the friction even smaller during a power cycle, allowing the engine to turn faster...


    Mechanical characteristics and efficiency factors such as friction losses throughout the engine will have a great effect on Torque , RPM, and Power, quality and shape of materials used, their strength and weight,their finish and tolerances, and their heat transfer and absorption qualities, to name a few.

    Here we will find crankshaft and camshaft,intake and exhaust valve and system designs to play major roles, complementing in the overall engine performance.


    Thermodynamic characteristics and efficiency, have to do with the quality of combustion achieved by an engine,the energy generated by the chemical reaction of the air-fuel mixture in the cylinder, how much of this energy is converted to Power, how much of this energy is transferred in the form of heated gases through the exhaust to the environment, and how much of it is transferred in the form of heat to the engine components and finally dissipated by the cooling system. Key factors here are fuel type and quality, mixture percentages, piston and cylinder head shape, the flow dynamics of the mixture through the intake system, the intake valves and in the cylinder chamber resulting in the uniform dispersion of this wild mixture just before combustion. During combustion, a well designed engine will transfer the optimum amount of energy through the piston in the form of Torque acting on the crankshaft, and will dissipate the rest, in a way that protects its components from damage. After combustion, the flow dynamics of the heated exhaust gases come to play in an equally great and challenging way through the exhaust valves and the rest of the exhaust system.


    A detailed description of the factors affecting a basic 4-stroke engine's performance and basic enhancements (tuning) can be found here and here among other places on the web.



    ENGINE PERFORMANCE IN GT-6


    In GT-6 Engine Performance, follows real life in a way, Power Torque and RPM, doing their usual stuff. Although Torque's effect is not that evident or as drastic as in real life, I find Torque in GT-6 playing a far greater role than it did in GT-5.


    So for people who are used to ignore Torque in their setups, and this includes major Tuners, this is the time to change their approach. Because in GT-6, Torque matters.


    For any given tuning part you add in your setup you will see different changes in Power and Torque.

    You will also note that for each of the tuning parts, you get a different RPM response, and a different max RPM. These changes are evident in the picture below:

    COLLAGE.png

    R8 4.2 FSI R tronic '07. Notice the changes to Power, Torque and RPM, as I keep adding the available tuning options one after the other. Top left is standard, Lower Right is fully tuned. Even the graph changes, although very vague and almost unusable IMO.


    So for anybody interested in tuning in GT-6 forget what you did in GT-5.

    Power is a good thing, but not the only good thing anymore.

    Torque and RPM combined with suitable gearing,
    can do wonders specially on difficult tracks.


    P.S. The quality of screen grabs sucks, please bear with me, until I find a way of capturing screens of GT-6 in a native way. (Now I shoot with my phone off the wall...).

    Has anybody found a way other than HDMI grabbers? If yes please let me know...

    In the rest of this thread, I will between other things try to investigate further, test and report my findings.
     
    Last edited: Mar 14, 2014
    Mamaghi, ToyGTone, gvmz and 12 others like this.
  5. yannagas

    yannagas

    Messages:
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    Location:
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    In this excellent thread @Hastatus showed that there is a 5% boost in Power when a oil change is performed. This gain will remain for 200 km. After this and in the next 100 km the car will lose that boost linearly.


    This experiment will show that the same applies to Torque



    1.OIL CHANGE BOOST EFFECT ON TORQUE.

    In this test, cars of different Performance Point Categories will receive on oil change, and results will be compared over standard values.


    Category 9 900+ PP

    001.png

    Category 8 800+PP

    002.png

    Category 7 700+PP

    003.png

    Category 6 600+PP

    004.png

    Category 5 500+PP

    005.png

    Category 4 400+PP

    006.png

    007.png

    Category 3 300+PP

    008.png

    Category 2 200+PP

    009.png

    010.png

    FINDINGS
    • There is an equal oil change boost of about 5% both in Power and Torque, in all categories.
    • PP gain is a fixed value of 4 to 8, spans all categories and does not seem to follow a percentage pattern.But it certainly follows some sort of pattern...Further digging required.
    • The above findings apply to tuned cars as well, in any tuning state, and that also includes the power limiter.
    • There is a constant data reporting error between Dealer card, Settings card and graph, and the Garage card. In all PP categories there was an error of 0.4 to 0.5 kgfm in Torque Values. In some cases there was a Power error of 1 BHP, and errors in max Power and or Torque rpm values.
    • Statistical error is quite high in all categories and especially evident in category 2 due to PD's Conversion, rounding, and small Torque numbers(kgfm).

    Next we'll see what happens with tuned cars, and how Torque behaves with oil boost deterioration
     
    Last edited: Mar 20, 2014
    Mamaghi, gvmz, romynovanda and 11 others like this.
  6. yannagas

    yannagas

    Messages:
    281
    Location:
    Greece
    2. OIL CHANGE BOOST EFFECT ON TORQUE (TUNED CARS).


    In this test, cars of different Performance Point Categories will be fully tuned, then they will receive on oil change, and results will be compared over standard values.



    Category 6 600+ PP

    101.png

    Category 5 500+ PP

    102.png

    Category 4 400+ PP

    103.png

    104.png

    Category 3 300+ PP

    105.png

    Category 2 200+ PP

    106.png

    FINDINGS



      • This test verifies that there is an equal oil change boost of about 5% both in Power and Torque, in all tested categories, even when the cars are fully tuned.
      • PP gain is a fixed value of 6 to 8, and does not seem to follow a percentage pattern. Looks like it has to do with starting PP value, because it differs in some cases from Standard to Fully Tuned. In the last test performed, the little Fiat gained 2 PP categories(from 216PP to 461PP) due to full tuning.
        So the PP gain from new Oil changed from 5PP to 7PP, a difference of 2 PP.
        The Honda gained 1 PP Category (from 350PP to 466PP) So the PP gain from new Oil changed from 6PP to 7PP, a difference of 1 PP.
      • There is a constant data reporting error between Dealer card, Settings card and graph, and the Garage card. In all PP categories there was an error of 0.4 to 0.5 kgfm in Torque Values. In some cases there was a Power error of 1BHP, and errors in max Power and or Torque rpm values.
      • Statistical error is quite high in all categories and especially evident in category 2 due to PD's Conversion, rounding, and small Torque numbers(kgfm).
     
    Last edited: Mar 20, 2014
    Mike458, Mamaghi, gvmz and 7 others like this.
  7. yannagas

    yannagas

    Messages:
    281
    Location:
    Greece
    3. OIL CHANGE BOOST EFFECT (STANDARD AND FULLY TUNED)
    50% POWER LIMITER


    In this test a Category 5 car (middle category) will receive an oil change in 4 states: Standard, Standard with 50% Power limiter, Fully tuned, and Fully tuned with 50% Power limiter.


    201.png

    202.png

    FINDINGS
    1. This test verifies that there is an equal oil change boost of about 5% both in Power and Torque, in all tested states, Standard, Standard with 50% power limiter, Fully tuned and Fully tuned with 50% power limiter.
    2. PP gain remains fixed at 7 PP except the last state (Fully tuned 50% limiter)where gain mysteriously becomes 8 PP...
     
    Last edited: Mar 20, 2014
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  8. yannagas

    yannagas

    Messages:
    281
    Location:
    Greece
    4. OIL CHANGE BOOST DETERIORATION EFFECT ON TORQUE


    It all started here... While racing the Diablo TT, I tried @beodo20vt 's tune, and did an oil change... That was the first time I ever did one, and probably the last...

    I noticed a big increase in Torque and tuned the Lambo accordingly,
    less power more torque, lower final gear, longer individual gears and was as fast in acceleration both uphill as well as in the straits, as I could catch @eclipsee 's ghost at some points, and even gain on him at others.


    While trying different suspension settings I noticed a sudden big drop in performance, and freaked out... @eclipsee informed me that I had to change the oil every 200 km, and pointed me to the Oil thread...


    So in the following test, that same car will receive an oil change, and then will be driven for over 300 km, to record changes to Power and Torque.

    301.png

    302.png

    303.png

    304.png

    FINDINGS
    Data recorded speaks for it's self. Both Power and Torque undergo the exact same changes. Oil boost deterioration starts on km 201 after the Oil change, and stops at km 301, where the car returns to pre Oil change state.

    Drop is absolutely linear in these 100 km at a rate of 1% of initial Oil change gain (boost), per kilometer.

    I suspect that Oil deterioration and Engine deterioration as described here affect Torque
    in the same way as Power. I will check further...
     
    Last edited: Mar 21, 2014
    Mamaghi, gvmz, romynovanda and 8 others like this.
  9. SGETI

    SGETI

    Messages:
    2,357
    Location:
    United States
    Wow. This a great read. Will need to re-read to wrap my head around all the info. Thank you for your time. In all honesty I will need to re-read more than once.
     
    xande1959, Ronald6 and yannagas like this.
  10. FussyFez

    FussyFez

    Messages:
    1,440
    Location:
    United Kingdom
    Excellent Info here, thanks alot for putting it all together. :gtpflag::cheers:
     
    t3kc0h and yannagas like this.
  11. yannagas

    yannagas

    Messages:
    281
    Location:
    Greece
    PD's Reporting Error: The "schizo" effect

    look at the images bellow, seems when you are buying a car, you are actually buying 3...

    At the Dealer's

    dealer 564_001.JPG

    At the settings page

    settings 564_003.JPG

    At the Garage Page
    garage 564_002.JPG

    So at the dealer's you get 631 BHP /7500 rpm , 64.2 kgfm /6200 rpm
    at the settings you get 630 BHP and 64.7 kgfm
    but in the garage you have 630 BHP / 7500 rpm and 64.2 kgfm / 5500 rpm

    You can pick the one you like better!
    or is it a 3 in 1 deal? :confused::D

    This error appears in every car tested so far...
    So until PD fixes this mess, I suggest using the Garage card data,
    as I find the settings page
    and graph very vague to say the least...
     
    Last edited: Mar 21, 2014
  12. Mirado_7

    Mirado_7

    Messages:
    371
    Location:
    United States
    Absolutely great read. Thanks so much for doing this!
     
    yannagas likes this.
  13. Youngun

    Youngun

    Messages:
    2,143
    Location:
    United Kingdom
    My head hurts reading all that so early. Great info though dude, that and oil info, i'll be a race machanic in no time lmao.
     
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  14. GTP_CargoRatt

    GTP_CargoRatt

    Messages:
    11,209
    Location:
    United States
    Wow, what a wealth of valuable information. :bowdown: So much to be learned here, thank you so much for taking the time to put this together for us. A very valuable resource for sure, much appreciated my good friend...you are the man. :bowdown: :cheers:

    EDIT: I have asked @Jordan that this be stickied.

    EDIT: The sticky request has been granted by @Jordan. :tup:
     
    Last edited: Mar 21, 2014
    Hastatus, Ronald6 and yannagas like this.
  15. yannagas

    yannagas

    Messages:
    281
    Location:
    Greece
    Wow what can I say! Sticky Torque! :lol: Thanks to all friends for their kind comments, I know there's a lot of stuff packed in here, so take your time to digest it, and feel free to ask for anything that needs further explanation or clarification.
    Ideas and thoughts you might have, or something you discovered in the numbers, or in the game and I might have missed, your input is more than welcome.
    There's allot more to come so stay tuned! (i like this last word!)

    Thanks again, specially to my buddy Mich for his kind gesture:cheers:, and to @Jordan for accepting his request!
    This Thread has consumed quite some time and effort, and this is a great reward!
     
    rams1de likes this.
  16. xande1959

    xande1959

    Messages:
    1,399
    Location:
    Brazil
    sir yannagas :bowdown::bowdown::bowdown::bowdown: . thank you for the excellent work enlightening, has a saying,..'re born dies without learning but I know I'll have to read much further sir yannagas an Oscar would be little congratulation :cheers::tup::gtpflag:
     
    Last edited: Mar 21, 2014
    yannagas likes this.
  17. ProjectWHaT

    ProjectWHaT

    Messages:
    13,369
    Location:
    Antarctica
    :tup: that's probably the most well written things I've read this week! Too bad I fell asleep like Jeremy Clarkson falling sleep when May's talking about...torque. It's just too confusing to me. >.<
     
    yannagas likes this.
  18. Motor City Hami

    Motor City Hami

    Messages:
    4,801
    Location:
    United States
    Are you doing any testing without oil changes? If you are racing anything other than maxed out tunes, oil change will actually be slower. Do an oil change use the power limiter to reduce things back to the stock PP level. You will actually lose performance. Plus, with no oil change, the engine does not seem to wear out... ever. Have they fixed this glitch by 1.05 and I have missed it?
     
    backnfourth likes this.
  19. GTP_CargoRatt

    GTP_CargoRatt

    Messages:
    11,209
    Location:
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    Just fyi, my name is Mitch, not Mich.:lol::lol: You keep forgetting the "t". :lol:

    Anyways, you're welcome and glad the request was granted...very deserving of it. :bowdown: Peace my good friend.
     
    yannagas likes this.
  20. yannagas

    yannagas

    Messages:
    281
    Location:
    Greece
    Totally agree, I normally never do an oil change, at least that's how i'm used to, and i don't really recommend it yet.
    It's too much of a hassle , having to change oil every 200 km.

    However when I tried it on the Diablo TT to replicate a tune by @beodo20vt who was top 20 or something like that, I was quite impressed. It seemed like there was an overall uniform boost in engine response throughout the entire rev span, even with the limiter in use to match the PP.

    I have found through experimenting, that the limiter plays a great role in conjunction with an oil change, since it actually limits Power linearly, but not Torque! It will actually start affecting maximum Torque after quite some heavy limiting, and even when that starts happening, maximum Torque will shift to lower rpm...
    I will post these findings shortly. I just need to make the tables.

    What I'm actually doing now is trying to analyze all the available tuning options in a statistical way, and then compare their PP, Power and Torque gains. Some sort of reverse engineering, to see how the guys at PD do it. It's not easy but that's what I'm after.

    So what I need to see now, is what other tuning combo will give you a 5% gain in both Power and Torque for as little as 4 to 8 PP, to really see if the oil change is a player worth the hassle.

    I have also seen some quite heavy engine deterioration due to bad oil in a XKR-S '11 that had no oil change, and i did 5627 km in that other TT in Rome if I remember well.
    It lost about 3.2% of its Power and Torque, compared to a new Jag.
    So I don't believe there's a glitch there, if you're talking about that.

    Mind you I have also found that there are no registered kms done in Arcade mode, so in that mode nothing changes.

    I'll post that too later, when i do more km, but i expect a total loss of 5% both in Power and Torque when it has reached 6000 km, as @Hastatus has shown for Power here.

    Thanks for visiting and dropping a line, I consider your tuning work great, I often check your thread and tunes,
    and will be happy to collaborate with you and gain from your knowledge and experience, as I'm sure the community will gain too!:tup:
     
    Last edited: Mar 23, 2014
    Hastatus and backnfourth like this.
  21. yannagas

    yannagas

    Messages:
    281
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    Sorry Mi ch I o ally forgo ha le er... :lol: ..bad brain cell :crazy: le me fix i ...:banghead:....:idea: Thanks Mitch!!! :cheers:
     
    Last edited: Mar 23, 2014
    GTP_CargoRatt likes this.
  22. GTP_CargoRatt

    GTP_CargoRatt

    Messages:
    11,209
    Location:
    United States
    :lol: Very nicely played my friend, clever response. :tup: Had a good laugh over that one. :lol:
     
    yannagas likes this.
  23. xande1959

    xande1959

    Messages:
    1,399
    Location:
    Brazil
    never change oil of my car, so when complete 1000 kilometers, not sure if it makes a difference, but I have a mazda 300 gt RX-7 Model base and inadvertently changed when oil was 1,200 Km inadvertently not made a note in the data but something happened improved after the car decreases (PP). 'll start to notice these details.:cheers::tup:
     
  24. backnfourth

    backnfourth

    Messages:
    96
    I started doing this with several cars. I was only looking at HP gain per PP for parts and certain part combos that were added. I can tell you that the major torque components are the Intake Tuning, Isometric Exhaust, turbos(varies) and supercharger, and engine tuning. These give significantly less power per PP but noticeably more torque. As far as power per PP the catalytic converter, sports computer, any of the exhausts, and often the combination of intake + turbo/surpercharger provide the most power per PP. As far as power/PP, when I did individual components I also included the oil change at it was always at or near the bottom of the list.

    I stopped looking into this because the basic roles became pretty clear and the numbers became more complicated. A lot of the numbers presented as finite whole number variables in GT6 are in fact continuous in my opinion. I've also yet to experience a car (aside from rally and some featherweight cars) that truly benefits from having torque components added to reach a PP level (maxing torque) vs. adding power components to reach the the same PP level (maxing HP)

    That's just what I think though. Great stuff you've posted. Very thorough testing. Kinda wish I had some of your basic physics explanations back when I was taking physics so I could think about those concepts in terms cars and not other weird textbook stuff.
     
    yannagas likes this.
  25. bread82

    bread82

    Messages:
    112
    Location:
    England
    @yannagas

    I loved reading this, especially the F1 vs NASCAR section, really interesting. You've clearly put a lot of work into both the RL theoretical section and the GT6 analysis. :tup::cheers:. Really well formatted too, which made it flow nicely and easy to read.

    Are you an engineer in real life, or just a car enthusiast that really likes to know how things work?
     
    yannagas likes this.
  26. yannagas

    yannagas

    Messages:
    281
    Location:
    Greece
    Well thanks for your kind words, nice to see you like the Thread,
    I have tried to uncomplicate things as much as possible, something not always easy to do in a way that everybody finds interesting to read. I know it still needs an effort to go through it, but anyway it's nice to get comments like yours.

    Now to answer your question, you can say I'm both. I have an engineering background and a passion for engines and almost anything that has one. I have raced MX and Enduro bikes, Karts and cars, and even constructed a weird looking vehicle with a 50 cc Ducati engine when i was 13 :). I kept heavily tuning cars that I owned, don't think pimp style tuning, but rather racing tuning (as far as Group A) in original "unsuspecting" bodywork. Anyway I'm 48 now and still find "knowing how things work" more fascinating than ever!
     
  27. yannagas

    yannagas

    Messages:
    281
    Location:
    Greece
    The hidden power of the Power Limiter

    In this experiment, I will try to see how the Power Limiter found in the Car settings page behaves.
    I initially tested two cars with similar engines I had in my Garage, both Naturally Aspirated, big displacement,
    The Lamborghini Diablo GT2, and the Audi R8 4.2 FSI .
    I recorded the power limiter's effect, in two states for each car. Standard and fully tuned.


    limiter 001.png

    limiter 002.png



    limiter 003.png

    limiter 004.png

    EARLY FINDINGS
    In both cars and in both states, the power limiter reduces Power in an absolutely linear way, at the exact rate of the Power limiter's nominal value. This i believe happens to all cars in the game.

    The above is not the case with Torque, which remains untouched in the standard state until 80% or more
    limiter is applied, and then follows a geometrical or exponential curve. More testing needs to be done.
    In the tuned state Torque limitation starts earlier, but again until around 80% limiter, the losses in Torque remain very small. In both states with full limiter (50%) applied, Torque suffers a loss of a maximum 17% in the worst case.

    The Power limiter affects the Power band in a very clear manner as the tables above show, the more limiter used, the more max Power and Torque shift to lower RPM. This can be beneficial some times with the use of a properly geared gearbox.
    Some erroneous values I believe are reporting glitches, need to crosscheck with the graphs, but PD has quite a history and we are used to that..

    PP at full limiter (50%) in the standard state had a total drop of 16% in both cars, while in the fully tuned state that drop was 14% for both cars. Seems the rate PP drops follows a variable geometric progress, further testing is needed.

    These tests give us valuable information concerning the relation between PP, Power and Torque, since we can see e.g. what 50% Power and 16% Torque with known values translate into recorded PP values.
    We can also extract valuable information, as to how much of a cars total PP value corresponds to its engine characteristics. Further testing is needed, and it wont be easy as i suspect engine PP is not only derived from its Power and Torque, but also from other category setting performance blocks like displacement and aspiration type.

    Anyway, looks challenging but I'll dig more..
     
    Last edited: Mar 25, 2014
    gvmz, Mamaghi, romynovanda and 7 others like this.
  28. Hastatus

    Hastatus

    Messages:
    720
    Very nice work! I'm glad I could inspire you.

    I only see one small issue:

    No one seems to know for sure who said:
    "Horsepower sells cars, torque wins races."
    It's been attributed to both Carrol Shelby and Enzo Ferrari. And maybe they each took it from someone else? Or maybe Enzo said it in Italian, instead of English. ;)
     
    yannagas and DaBomm4 like this.
  29. yannagas

    yannagas

    Messages:
    281
    Location:
    Greece
    Well yes that's an issue alright! Who knows? There was no internet back then... Europe and America where two different worlds... So Enzo in his world and Carrol in the other... Both where Racers. Racing Patrons and business men making and selling cars...Both companies made Torque monsters...And there is a bad connection up there where they both hang out!:) So I edited the post to be fair to both!:lol:
     
  30. saidaouita

    saidaouita

    Messages:
    431
    I have smoke coming out of my ears and you call it a great read?

    ;)
     
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