Diesel Chips / Diesel Tuning - How Its Done
Posted: Wed Dec 14, 2011 10:14 pm
Considering how many threads get started that I end up commenting in regarding diesel chips, performance products, intercoolers and how they work has become a daily occurrence for me (as much as I love helping people, I generally end up getting flamed down by other workshops for telling the truth or asking the hard to answer questions)
I thought it might be a good idea to start up one thread, with the intention of separating fact from fiction regarding these topics.
Diesel Performance Chips: 2 Catagories (CR/Pre CR)
First a basic break down of what happens on each piston cycle in a diesel engine.
The engine control unit reads a lot of sensors before it decides when, and how much fuel to inject on each engine cycle.
Crank Angle Sensor: The ECU reads this to determine which piston is next to fire, and how far away it is from its injection point.
Boost Sensor/Manifold Absolute Pressure Sensor (MAP): The ECU reads this to determine how much air pressure is going into the cylinder. The more pressure, the more oxygen that is available to burn the fuel thats injected.
At sea level, the pressure in the engine is 14.7 pounds per square inch (PSI). Anything shown in Gauge pressure, is 14.7psi + boost in PSI.
Air Temperature Sensor: As critical as air pressure. The cooler the incoming air is, the more oxygen that is available to burn the diesel that is injected into the cylinder.
This component of it is as important as air pressure when it comes to engine longevity.
Engine Coolant Temperature: Used as a compensation by the ECU to determine if too much fuel is being injected resulting in very high combustion temperatures.
Exhaust Gas Temperature: Rarely used by OEM ECU as the EGT does not indicate actual combustion temps on modern day diesel engines. Only water temp gives a true reading of actual combustion temps due to post combustion fuel injection that keeps EGT high to help drive the turbocharger exhaust wheel.
Throttle Position Sensor: Is used by the ECU to determine how much torque is being requested by the driver.
Common Rail Pressure Sensor: Measured by the ECU to determine how much pressure the CR pump is delivering.
Now to the Types of chips and how they Deliver.
Common Rail Chips: Comprises of two types of chips (Injector Extender and Pressure Increaser)
Pressure Increaser Chip:
The 'Chip' takes the common rail pressure sensor signal and drops it by X voltage so the engine control unit sees 'low' pressure at the common rail sensor.
The ECU then tries to correct this low voltage by demanding more pressure from the common rail pump.
This increase of common rail fuel pressure pressure increases the amount of diesel each injector fires, thus increasing power accordingly with the extra fuel injected.
Injector Extender Chip:
The engine control unit fires the injector when required, the 'Chip' does not allow the ECU to close the injector when it is asked by the ECU. It keeps it open for a few milliseconds longer which allows more fuel to be added per injector fire sequence.
Power is supplied to each injector constantly and the ecu turns the earth on to open the injector and off to close it.
The injector extender chip watches for end of injection point, and maintains the earth contact to keep the injector open.
This type of chip plugs directly into each injector between the ecu plugs and the injector itself. As it is extending only one injector at a time, there is no other way to go about it.
Fuel Pressure Chips: Plug into the Fuel pressure Sensor on the common rail.
Extender Chips: Plug into injectors.
Chips that can adjust injection timing: Plug into the crank angle sensor.
Chips that can adjust Boost: Plug into the MAP (Manifold Absolute Pressure) Sensor.
Chips that can control Everything in one: Plug into the main ECU harness
CANBUS Explained:
What is CANBUS: Controller Area Network is what it stands for.
It basically means every sensor can be connected to the same wire, and each sensor has its own address. So commands issued by the ecu are headed with a certain address and each sensor will only respond to the signals with its address tagged onto it.
Four wires are normally used on a CANBUS system. CAN-HI and CAN-LOW, V+ & V-
CAN-HI is used for systems such as airbags, abs and other critical systems. The CAN HI signal will always be dealt with first by the ecu as they are more important
CAN-LOW is used for systems such as indicators, lights, seat warmers etc.. Non Critical systems.
There is often many seperate CANBUS circuits through out the car. Engine Control / Gearbox Control / SRS Controls / Lighting etc..
A sudden surge of companies are pushing this so called 'New Technology' onto customers.
Calling their chip's CANBUS controllers or the likes, claiming only 3-5 wires are necessary to control ever engine function under the sun.
As far as I know, no Common Rail diesel vehicles are sold in Australia that use a CANBUS system for engine control at all. Even the VW Toureg TTV10 does not use it for engine control! I cannot think of a more technologically advanced Diesel 4x4 in the country.
Each control system has its own dedicated circuit/wiring back to the ecu. This includes Fuel Pressure > Boost > Engine RPM > Throttle Position > And everything else needed to run the engine.
The only few engines I know of that do run any CANBUS system is some older VP44 Pump equipped cars such as the early 3.0L Patrol and Holden Rodeo.
And the only CANBUS system used on these is pump control.
If anyone is trying to sell you a 'CANBUS Chip' or pushes this kind of technology in their advertising, I urge you to bring it to the public's attention. You could save yourself money on a misleading under performing product, and even better save alot of other people's money to.
If you are in doubt at all about the 'supposed' claims of any chip, bring it up in a public forum. Hear others experience, Get proper advice and avoid wasting your money.
If what they are selling is indeed misleading and false, name and shame them. Its the only way people wise up. If members dont do this, companies continue to make money off abusing peoples trust.
Each type of chip has pros and cons.
Pressure Chip Pros:
More pressure = better atomisation of the fuel. The finer the droplets of fuel are, the easier they mix with oxygen molecules, which helps the fuel to burn more completely.
Pressure Chip Cons:
Lets say the ECU is demanding 25,000 psi and getting a feedback reading of 20,000 psi it will eventually pick up that something is wrong and put the car into limp-home mode.
Generally it detects a fuel leak, as its demanded pressure is much higher than actual pressure. This limits this type of chip to how far the factory sets its 'fail safe defaults' outside of the operating range.
It also poses a problem of putting the common rail system past its maximum safe working load.
Most systems will cope with 24,000-28,000psi constantly. It is very common for chips to have the systems working at or past their recommended limit. The risks to this are, common rail splitting/breaking, injectors splitting/leaking, or injection lines starting to leak from their joints.
Injection Chip Pro's:
Is undetectable by the ECU as it is holding the injector open after the ECU demands a close point. The ECU cannot measure if the injector is open or closed! It relies on the fact that the injector is doing what the ECU is demanding of it.
Injection Chip Cons:
The longer the injector stays open, the lower the fuel pressure behind it will be.
Lower injection pressure generally results in less atomisation of the fuel, which will not mix as easily with the oxygen and thus will not burn as easily.
Spill Valve Timing / Pre CR Chips: Clearing up the big myth.
What is a spill valve?
It allows more or less fuel to pass through the injector pump. Effectively giving us electronic control over how much fuel is injected.
Just as with our CR injector chips. A spill valve chip, will allow us to hold the valve open longer than the ecu is allowing, by supplying an earth source to the valve after the ecu has turned it off.
When people talk about spill valve timing, alot of them confuse this with actual injection timing.
Spill valve timing relates to how long the valve is held open. The longer it is open for the more fuel that will be allowed to pass.
These types of pumps run an advance slide that is also controlled electronically. This is what moves the actual injection timing of the pump. Not the spill valve.
Air Before Fuel Philosophy:
To burn any type of fuel, oxygen is required. More oxygen content gives us a couple of options.
1) The ability to burn more fuel.
2) The ability to burn the fuel we already have more completely.
They sound similar, but in actual fact are vastly different in a diesel engine.
Completing #1 will always result in more power from a diesel engine. More fuel will almost always results in more power.
The way a diesel molecule burns is like peeling an onion, it continues to burn, layer after layer. Which always keeps the temperature and pressure in the cylinder high (more power).
The main problem is the longer it burns for, the higher your engine/cylinder temperatures will be (resulting in engine damage from excess
I thought it might be a good idea to start up one thread, with the intention of separating fact from fiction regarding these topics.
Diesel Performance Chips: 2 Catagories (CR/Pre CR)
First a basic break down of what happens on each piston cycle in a diesel engine.
The engine control unit reads a lot of sensors before it decides when, and how much fuel to inject on each engine cycle.
Crank Angle Sensor: The ECU reads this to determine which piston is next to fire, and how far away it is from its injection point.
Boost Sensor/Manifold Absolute Pressure Sensor (MAP): The ECU reads this to determine how much air pressure is going into the cylinder. The more pressure, the more oxygen that is available to burn the fuel thats injected.
At sea level, the pressure in the engine is 14.7 pounds per square inch (PSI). Anything shown in Gauge pressure, is 14.7psi + boost in PSI.
Air Temperature Sensor: As critical as air pressure. The cooler the incoming air is, the more oxygen that is available to burn the diesel that is injected into the cylinder.
This component of it is as important as air pressure when it comes to engine longevity.
Engine Coolant Temperature: Used as a compensation by the ECU to determine if too much fuel is being injected resulting in very high combustion temperatures.
Exhaust Gas Temperature: Rarely used by OEM ECU as the EGT does not indicate actual combustion temps on modern day diesel engines. Only water temp gives a true reading of actual combustion temps due to post combustion fuel injection that keeps EGT high to help drive the turbocharger exhaust wheel.
Throttle Position Sensor: Is used by the ECU to determine how much torque is being requested by the driver.
Common Rail Pressure Sensor: Measured by the ECU to determine how much pressure the CR pump is delivering.
Now to the Types of chips and how they Deliver.
Common Rail Chips: Comprises of two types of chips (Injector Extender and Pressure Increaser)
Pressure Increaser Chip:
The 'Chip' takes the common rail pressure sensor signal and drops it by X voltage so the engine control unit sees 'low' pressure at the common rail sensor.
The ECU then tries to correct this low voltage by demanding more pressure from the common rail pump.
This increase of common rail fuel pressure pressure increases the amount of diesel each injector fires, thus increasing power accordingly with the extra fuel injected.
Injector Extender Chip:
The engine control unit fires the injector when required, the 'Chip' does not allow the ECU to close the injector when it is asked by the ECU. It keeps it open for a few milliseconds longer which allows more fuel to be added per injector fire sequence.
Power is supplied to each injector constantly and the ecu turns the earth on to open the injector and off to close it.
The injector extender chip watches for end of injection point, and maintains the earth contact to keep the injector open.
This type of chip plugs directly into each injector between the ecu plugs and the injector itself. As it is extending only one injector at a time, there is no other way to go about it.
Fuel Pressure Chips: Plug into the Fuel pressure Sensor on the common rail.
Extender Chips: Plug into injectors.
Chips that can adjust injection timing: Plug into the crank angle sensor.
Chips that can adjust Boost: Plug into the MAP (Manifold Absolute Pressure) Sensor.
Chips that can control Everything in one: Plug into the main ECU harness
CANBUS Explained:
What is CANBUS: Controller Area Network is what it stands for.
It basically means every sensor can be connected to the same wire, and each sensor has its own address. So commands issued by the ecu are headed with a certain address and each sensor will only respond to the signals with its address tagged onto it.
Four wires are normally used on a CANBUS system. CAN-HI and CAN-LOW, V+ & V-
CAN-HI is used for systems such as airbags, abs and other critical systems. The CAN HI signal will always be dealt with first by the ecu as they are more important
CAN-LOW is used for systems such as indicators, lights, seat warmers etc.. Non Critical systems.
There is often many seperate CANBUS circuits through out the car. Engine Control / Gearbox Control / SRS Controls / Lighting etc..
A sudden surge of companies are pushing this so called 'New Technology' onto customers.
Calling their chip's CANBUS controllers or the likes, claiming only 3-5 wires are necessary to control ever engine function under the sun.
As far as I know, no Common Rail diesel vehicles are sold in Australia that use a CANBUS system for engine control at all. Even the VW Toureg TTV10 does not use it for engine control! I cannot think of a more technologically advanced Diesel 4x4 in the country.
Each control system has its own dedicated circuit/wiring back to the ecu. This includes Fuel Pressure > Boost > Engine RPM > Throttle Position > And everything else needed to run the engine.
The only few engines I know of that do run any CANBUS system is some older VP44 Pump equipped cars such as the early 3.0L Patrol and Holden Rodeo.
And the only CANBUS system used on these is pump control.
If anyone is trying to sell you a 'CANBUS Chip' or pushes this kind of technology in their advertising, I urge you to bring it to the public's attention. You could save yourself money on a misleading under performing product, and even better save alot of other people's money to.
If you are in doubt at all about the 'supposed' claims of any chip, bring it up in a public forum. Hear others experience, Get proper advice and avoid wasting your money.
If what they are selling is indeed misleading and false, name and shame them. Its the only way people wise up. If members dont do this, companies continue to make money off abusing peoples trust.
Each type of chip has pros and cons.
Pressure Chip Pros:
More pressure = better atomisation of the fuel. The finer the droplets of fuel are, the easier they mix with oxygen molecules, which helps the fuel to burn more completely.
Pressure Chip Cons:
Lets say the ECU is demanding 25,000 psi and getting a feedback reading of 20,000 psi it will eventually pick up that something is wrong and put the car into limp-home mode.
Generally it detects a fuel leak, as its demanded pressure is much higher than actual pressure. This limits this type of chip to how far the factory sets its 'fail safe defaults' outside of the operating range.
It also poses a problem of putting the common rail system past its maximum safe working load.
Most systems will cope with 24,000-28,000psi constantly. It is very common for chips to have the systems working at or past their recommended limit. The risks to this are, common rail splitting/breaking, injectors splitting/leaking, or injection lines starting to leak from their joints.
Injection Chip Pro's:
Is undetectable by the ECU as it is holding the injector open after the ECU demands a close point. The ECU cannot measure if the injector is open or closed! It relies on the fact that the injector is doing what the ECU is demanding of it.
Injection Chip Cons:
The longer the injector stays open, the lower the fuel pressure behind it will be.
Lower injection pressure generally results in less atomisation of the fuel, which will not mix as easily with the oxygen and thus will not burn as easily.
Spill Valve Timing / Pre CR Chips: Clearing up the big myth.
What is a spill valve?
It allows more or less fuel to pass through the injector pump. Effectively giving us electronic control over how much fuel is injected.
Just as with our CR injector chips. A spill valve chip, will allow us to hold the valve open longer than the ecu is allowing, by supplying an earth source to the valve after the ecu has turned it off.
When people talk about spill valve timing, alot of them confuse this with actual injection timing.
Spill valve timing relates to how long the valve is held open. The longer it is open for the more fuel that will be allowed to pass.
These types of pumps run an advance slide that is also controlled electronically. This is what moves the actual injection timing of the pump. Not the spill valve.
Air Before Fuel Philosophy:
To burn any type of fuel, oxygen is required. More oxygen content gives us a couple of options.
1) The ability to burn more fuel.
2) The ability to burn the fuel we already have more completely.
They sound similar, but in actual fact are vastly different in a diesel engine.
Completing #1 will always result in more power from a diesel engine. More fuel will almost always results in more power.
The way a diesel molecule burns is like peeling an onion, it continues to burn, layer after layer. Which always keeps the temperature and pressure in the cylinder high (more power).
The main problem is the longer it burns for, the higher your engine/cylinder temperatures will be (resulting in engine damage from excess