Chip Tuning - The Reality, The Myths and Everything Inbetween

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In this section we hope to dispel the myth/ignorance that have been instilled into many chip tuners. The resulting information is plain engineering fact and direct experience of the combined 50 years trade and formal education in our trade.

Custom Tuning Files

Fact - In chip tuning there is no such thing or ever was..

For any formally qualified automotive/calibration engineer the custom remap debate is amusing to say the least for a number of reasons;

Firstly – After 2004 most engine management systems became a closed looped torque based model simply put, the engine management is adapting (optimizing) the tune of the engine in almost real time based on the hard code or what is known as the statistical dynamics element of the memory. A quality remapping engineer understands and respects this and simply enters the correct desired targets in the correct places to the code and the system references the sensors accordant (closed loop or PID) thus using these settings to achieve the desired result. The one and only time a 'custom' strategy is required is when a vehicle is modified to a point where the dynamics employed by the factory ECU are no longer valid for example - a larger turbo is fitted requiring new PID loops to be employed.

"Even under these circumstances, only a small modification is required to a base calculation within the ECU to correct the internal equation."

Think of an ECU in its simplest form, it's a calculator programmed to receive values in terms of voltages and frequencies at a rate of 1 to 200 HZ or in layman's terms 1 to 200 times a second dependent on the type of value it needs to sample. For example - sensor values such as coolant temperature, are a slow changing value, so a sample of 1-5 HZ is fine. Where fast changing variable's such as manifold pressure, It requires a faster sample rate of say 50 HZ or 50 times a second. The processor then first of all references (for the sake of this explanation) three memory models within the ECU, one known as 'statistical elements' and the others as we know them as 'maps' and 'curves'

Statistical elements

Ideal gas.png

This is the core structure of the ECU function - It can be made up by a number of control algorithms such as 'Motronic' and elemental rules such as ideal gas law, this also includes configuration switches and curve/map address library for the controller to switch between based on the strategy or mode required.

Curve

MAF-EXP.png

The curve structures in the ECU are a vital and are often mistaken as torque limiters by 'CUSTOM MAPPERS' or re-scaled in a effort to bypass a mechanical limit resulting in a loss of resolution and refinement. An ECU can only interpret what a engine is doing by its input signals via the relevant sensors. This is usually done by voltage or frequency - so the 'curve' is the real world signal conversion to a digital value the ECU can use in a calculation to out put to its PWM's

Map

Injector-1.jpg


Basically a data matrix, a table of data values arbitrated to a output of the ECU drivers or PWM's referencing values such as requested torque, boost, lambda and air flow. These are desired targets based on the data and control logic influenced by the 'curve' and 'statistical elements'. ALL employing PID control - understanding this will expose the ignorance of most chip tuners.

Advanced ECU Engineering Principles

Diesel Tuning / DPF Removal and Smoke Emissions

No Smoke No Poke

Basic engineering fact - Smoke is WASTED energy This is the product of a badly written calibration, by normally adding fuel because its the easy and quick map to find with absolutely no recognition to thermodynamic principles,stoichiometry or Volumetric efficiency. A correctly written calibration will provide the cylinder with the correct amount of air to completely combust the given fuel. PLEASE understand that fuel is fixed sum (energy) for the ECU and air is variable, an engine is driven by the heating of air to gain the most power you must heat as much volume of air as possible from a relative due point (exothermic reaction), the fuel already in cylinder must be burnt completely to extract the most energy (allowing for the boundary layer), a complete burn of fixed fuel = more heat, more heat = more power, basic physics.

Diescyc.gif

Manufacturers go to huge lengths to achieve the perfect/maximum thermal efficiency in engine design striking the perfect balance from a induction temperature and the heating point of the fuel vs permissible exhaust temperature (EGT) whist targeting the idea push/pumping(expansion) cycle or adiabatic process. The problem in tuning a diesel engine for a manufacturer is purely down to controlling EGT relative to particle matter and Nox (nitrogen oxide) emissions the very reason forcing the use of DPF systems.

So how is the damage done? By modifying the lambda (fuel relative to air) the first issue is the over loading of the DPF management cycle as the filter is designed to handle a certain amount of matter vs measured flow vs a oil quality / engine ageing strategy, think of it like this - tuning an engine, it is a given performance air filters, they provide more airflow by using better, more expensive materials.

Currently there is no material solution for DPF to achieve performance increase other than (at best) an increase regeneration cycles to keep flow optimized resulting in increased fuel use for such a regeneration leading to the inevitable shorted life cycle. So adding fuel = Dead DPF.

Turbochargers suffer greatly from tuning ignorance, and are a fundamental component in managing the efficiency of a engine. The compressor map of a turbo dictates the dynamics of the air heating process with the cylinder temperatures vs EGT calibrated precisely known as the 'flame wall' as diesel fuel ignition timing is dictated by the mass vs relative fuel temperature respecting thermodynamic variables / e.g. - the fuel pressure (endothermic reaction), fuel mass (duration), start of injection (timing).

We see issues with calibrations where the mass (duration) is modified, the SOI (timing) is modified along with increased rail pressure resulting in the movement of the flame wall causing a cascade rise in EGT, thus damaging the turbocharger due to the paradox of increased boost pressure only compounding the issue. Another issue born out of over fuelling and flame de-tuning is the sooting of the exhaust wheel of the turbo causing an imbalance of the turbine and jamming of the variable geometry setup where applicable, thus greatly reducing the life of the turbocharger.

Drive line and chassis harmonics - Manufacturers again go to huge length to control engine running frequency and this 'noise' causes long term damage to components. A simple example is the presence of a dual mass flywheel, which is tasked in part to countering this issue in conjunction with tuned engine mounts and phased injection strategies.

  • By not respecting these components in a calibration, all will lead to early failure.

The work is already done in the ECU to increase the performance to a sensible point without compromising the power train. The key is understanding the physics on which the calibration was designed, so the next time you see a youtube video of a vehicle pumping a dyno cell full of black smoke think about what you have read here and the ignorance of some tuners.


Rolling Roads: THE FACTS

Rolling roads are a way to measure the power of a vehicle. However, they can also lead to many an unhappy and confused car owner as results can often be misread due to a general lack of understanding of the limitations, drawbacks and also benefits of a rolling road.

There are a few fundamental things you should know about rolling roads:

  • It is impossible for a rolling road to simulate real world driving. Rolling roads provide linear load on the engine and do so with a slow pull from low RPM’s to redline. It can take up to 45 seconds to reach redline. This amount of time and constant load on an engine and turbo charger will inevitably raise intake temperatures well beyond what the real world driving will see.
  • Raised intake temperatures will cause the ECU to factor the boost / fuel / timing maps to reduce load, thus limiting power. This is a protection feature.
  • It is very common for a car to have less rolling road performance and yet maintain strong power on the tarmac. This can be attributed to several factors.
  • The fan we usually see in front of the vehicle when a vehicle is on the rollers is providing a linear flow of air (constant flow/volume/temp), usually to a small portion of the frontal area of the vehicle. If we were to compare this to real world conditions, we can prove airflow is proportionately increased as speed is increased. This isn't replicated with the airflow on a dyno. This causes the air intake temperature to be well outside of what we would see if we were to log temperature on the road. The higher these temperatures get, the lower power output will be. So from this we can make some assumption that a car will probably make more power on the road than the dyno.
  • The final figure will also be variable with weather. Ever noticed on a cool, damp evening your car seems faster??

HEAT SOAK

A term used when an engine doesn't get adequate cooling for the given running conditions and the ECU will be forced to compensate for the additional heat. When a car suffers from heat-soak the ECU will typically go into an Exhaust Gas Temperature protection mode; lowering the requested load and increasing the amount of fuel in attempt to cool things down, this results in the curve tailing off much quicker than expected and a lower than realistic power output.

  • The majority of rolling roads will load a vehicle up during a power run in a certain way, this can vastly effect how the car ‘behaves’ on the rolling road as the ECUs are load based. All requests to the engine are calculated based on the feedback the ECU has from the engine and the load it’s under.
  • This doesn't even take into account any potential issues that could be inherent with a car, the amount of heat already in the car before it goes on the rollers, or any inconsistencies between operators and rolling road calibration. For Example: vehicle weight, number of cylinders, transmission type, air temp, air pressure. All factors not entered into the dyno software correctly that can lead to BS figures.
  • Wheel and flywheel figures can be a source of confusion, and there’s a danger of back-calculating flywheel figures from a chassis dyno. Power at the wheels is more meaningful and fairly accurate so long as the ambient and intake temps are reasonable. Certain rolling roads calculate force applied at the rollers, everything from there on is a mathematical equation and as such don’t necessarily give you accurate figures.
  • One of the biggest mistakes people make is to take a figure from a Rolling Road as gospel. There are so many varying factors between different dynos that can affect the output, (as mentioned above), that can differentiate vastly from one rolling road to the next. Realistically, a Rolling road can be a great tool to show differences from the fitment of additional hardware, but in the guise of a rolling road ‘shoot-out’ for a one off reading they are a waste of time.

“A figure or power curve only shows what the car is doing on that dyno, on that day, in those conditions.”

  • Using a Rolling Road to show the difference between cars or show the increase from software can also be unrealistic without correct preparation. If you have two identical cars running the same quality fuel, tyre pressures, etc. you can still have a variable within the ECU due to differing driving styles and conditions the cars see. One car might have been used much more aggressively than the other and have a much larger correctional factor due to adaptation from excessive heat. This can vastly affect the power output of a vehicle. Something else to be aware of is after programming an ECU the car will take a certain period of driving time to adapt (short/long term fuel trim), this period of time is dependent on driving style and conditions.

What is important is a road test and inspection of the vehicle before it's flashed. A full check over of the vehicle to see if there are any issues that need addressing prior to software being installed.

PEAK FIGURES

  • The peak numbers you get on a rolling road are typically referred to as ‘Pub Talk’ numbers; who has the most power and torque! In reality the Peak numbers are largely irrelevant; it's the power/torque throughout the rev range and the power delivery that's important, the peak number gives very little indication to how capable a vehicle is or how well it drives. Unfortunately there’s a lack of understanding in the industry and still a requirement to quote peak figures?

At the end of the day peak power and torque figures are all pub talk and mean very little in real world conditions. Peak figures don't give you any indication of drivability or even a true indication of increased performance as they ignore the power/torque curve and can’t tell you how smooth, powerful and efficient the power is delivered.

  • The general consensus is the higher the number the better, numbers sell. A 300hp car sounds much better than a 280hp car! But in reality what can you tell by these numbers?
  • First of all, quoted power and torque numbers are peak figures, they are the highest seen figures on a power or torque curve. They tell you what power and torque a vehicle is making on that dyno but those figures are really only useful for bragging rights. For a true indication of how a vehicle will feel and where the benefits of tuning can be seen you need to assess the power and torque curves, In the below example there are three power curves,
  • Purple is stock
  • Red is stage 1
  • Dashed blue line is hypothetical

Dyno.JPG

  • On paper the dashed blue line makes the most power as it peaks nearly 10bhp higher.
  • However from 2400rpm through to 6000rpm the red curve makes a lot more power.
  • At 3500rpm the red curve is 50bhp more than the dashed blue curve.
  • On the road, a car running the red curve (with a lower power output) would be a much quicker car.

This is a good example of how a peak number can be very deceptive and not tell the full story. You can see the difference in the area under the curves and how much more the red curve has gained throughout the rev range in comparison to the dashed blue curve

We don’t go chasing peak numbers but getting the balance between power and drivability is key.

Whilst an understanding of peak figures and power under the curve is important, it’s just as important to understand that rolling road results can and do vary and aren’t always a true representation of what a car will do in the real world.

I HOPE THIS WILL MAKE SENSE, AND YET AGAIN, TAKE OUT MORE BS FROM THE INTERNET FORUMS.

EGR Valve Removal, The Plain Facts

Its a well documented obsession of enthusiast diesel owners to remove an EGR valve or an owner with a faulty EGR valve, the want to remove it.

EGR removal in engineering terms will break down into a number of issues.

We are currently seeing tuners offering EGR deletes on vehicles equipped with LIVE DPF systems. We DO NOT offer this service for a number reasons. First of all, as part of the integral emissions system that was embedded into the software, the EGR and DPF systems work together in the regeneration process, as such we only remove EGR functions with DPF deactivation.

If the EGR system is deleted by means of duty cycle and airflow modification, this will have a negative impact on the DPF regeneration cycle. The DPF system was designed to work along side the EGR using different strategies in the passive and active regeneration process.

Gasoline / Petrol Stage 1234+ Tuning

FACT - Its a load of non-sense, its either tuned correctly or not.

Usually started from vehicle owner forums run/owned/funded by tuning companies thus pushing 'sponsors' -- pushing the myth that every time an extra piece of hardware is installed on the engine, then a calibration adjustment is required. To a certain degree this is true when you get to high levels of modification. In the eyes of the general public, this poses a grey area between the stage 1 and 2 ++ tune calibration. On a modern torque based petrol ECU, the fitting of the following requires NO further modification;

  • Full exhaust system with Decat
  • Cold air intake system or air filter replacement
  • Inter-cooler upgrade
  • Basically anything that improves airflow and/or lowers intake temperature into and from the engine.

The truth of the matter is, a correctly calibrated ECU will be able to deal with the extra air or air at a higher relative density (cooler) thus adjusting fuel and advance trims accordingly (adaption). This is where people assume, that having all of this hardware fitted they require further adjustments.

It has should be noted that some companies offer stage 1 and 2 tunes to completely stock vehicles. After 20 years we are still waiting for some one to explain what the difference is.

The requirement for a further calibration would be hardware such as;

  • Upgraded much larger turbocharger
  • Upgraded injectors / fuel system
  • Larger MAF or modification to run on MAP alone (Alpha N)
  • Basically anything that requires re-calibrating or re-scaling from standard production sensor curve (input)

Even then how this falls in the the mythical stage scale is yet to be seen. ITS EITHER TUNED CORRECTLY OR NOT.

ECO Tuning and Driving Style Changes

Fact - A client has owned a vehicle for (X) amount of time, over that period time regardless of how the vehicle is driven the client will have a very good idea on how economical their vehicle is. They have an ECO tune as they would like to gain extra economy, driving exactly the same journeys as before the remap. Soon after they realize that the return is the same or worse and only to be told that they need to drive the vehicle in a different manor. At this stage alarm bells should be ringing as this exposes several problems.

  • cover up of a poor product
  • incorrectly calibrated data
  • the engine is running inefficiently

An engine running more efficiently will not require different load conditions. To summarize, vehicles used daily on similar routes with a PCW ECO calibration will return extra MPG under the same operating conditions.

Clone / Copied Tools

FACT - with most things in life, there will always be copies, clones, rip offs. For example DVD movies and CD Albums. When it comes to chip tuning, Yes many tools have been copied/cloned etc. A quick google search will reveal the extent of how many clone tools are a wash over the internet. As an example, try and search FGtech for the legitimate FGtechnology website, lets put it this way, its not in the top 10 results. The fact that china has gone all out on manufacture and marketing of these tools, and even to the point of starting websites with very similar names means that people very little experience in chip tuning may be duped into thinking they are buying a legitimate tool a fraction of the cost of the genuine article.

DO clones Works?

This question is very difficult to answer, as clones are clones and it will be up to the user to test. The quality of the components and construction varies. The tools cannot be used while connected to the internet, so they cannot be updated to the very latest software/firmware, some protocols may or may not work due to old or corrupt software/hardware. The best source of information on these tools is the internet, like a chip tuning forum etc, although most major chip tuning sites actually ban the talk of clone tools, as you can imagine this is quite a taboo subject.

For someone looking to start up a professional chip tuning business, then there in no compromise for a genuine tool. Genuine tools are built as the manufacturer intended, All of the protocols listed 99% of the time work, so there is no real chance of error.

WE DO NOT USE OR SELL CLONE TOOLS - We are a file Calibration service

The economy of the clone tool market for a professional tuner is a false one. If you take into account possible lost time/earnings and replacement of damaged ecu's, it doesn't take many bad jobs to be at the same expenditure that a genuine tool would cost in the first place. Where possible, always use a genuine tool.

If you require advise or would like to order a particular GENUINE tool then we will be more than happy to help.