Chip tuning
Encyclopedia
Chip tuning refers to changing or modifying an EPROM
chip in a car
's or other vehicle's electronic control unit
(ECU) to achieve better performance, whether it be more power, cleaner emissions, or better fuel economy
.
This was done with early engine
computer
s in the 1980s and 1990s. Today, the term chip tuning can be misleading, as people will often use it to describe ECU tuning that does not involve swapping the chip. Modern ECUs can be tuned by simply updating their software through a standard interface, such as OBDII
. This procedure is commonly referred to as engine or ECU tuning. ECUs are a relatively recent addition to the automobile, having first appeared in the late 1970s.
As technology advanced, so did the electronics that go into cars. The ECU in a modern automobile, together with advanced engine technology, makes it possible to control many aspects of the engine's operation, such as spark timing and fuel injection
. The ECU may also control electronic throttle control
(drive-by-wire), valve
timing, boost control (in turbocharged
engines), ABS
, the automatic
transmission
, speed governor (if equipped), and the electronic stability control
system.
Performance gains are realized by adjusting the ignition timing advance. Higher timing may result in higher performance. However, to cope with advanced timing, one must run high-octane gasoline to avoid pre-ignition
detonation or pinging. Manufacturers design for a specific timing and this may limit performance accordingly.
In addition, changing fuel maps to coincide with the stoichiometric
ratio for gasoline combustion may also realize performance increase. Most manufacturers tune for optimum emissions and fuel economy purposes which can limit performance.
Cars with a turbo fitted can have the requested and allowable boost levels raised, these applications usually have the most effect if the turbo fitted is a low pressure turbo which leaves the most room for improvement.
Another reason to change the ECU map is if there are engine, intake, or exhaust modifications to the car. These "bolt-on" modifications alter the way that the engine flows, often causing the air to fuel ratio
to change. Without re-mapping the fuel tables, some of the performance gains from the modifications may not be realized.
A poorly tuned ECU can result in decreased performance, driveability, and may even cause engine damage.
The most common way to 'upgrade' the ECU is using either plug in modules as mentioned above or using a specialist tuner who will use an OBD Flash tool. These devices generally plug into the diagnostic port although in some cases the reprogramming is done directly on the circuit board
. Maps are supplied by tuners.
An alternative to modifying the on-board chip is adding an external device, often known as a tuning box. The abilities of the external devices generally reflect on-board chip modifications, with the advantage that they can be easily removed to restore the vehicle to standard. Adding an external tuning box is generally only possible on modern engines with external management ports.
EPROM
An EPROM , or erasable programmable read only memory, is a type of memory chip that retains its data when its power supply is switched off. In other words, it is non-volatile. It is an array of floating-gate transistors individually programmed by an electronic device that supplies higher voltages...
chip in a car
Čar
Čar is a village in the municipality of Bujanovac, Serbia. According to the 2002 census, the town has a population of 296 people.-References:...
's or other vehicle's electronic control unit
Electronic control unit
In automotive electronics, electronic control unit is a generic term for any embedded system that controls one or more of the electrical systems or subsystems in a motor vehicle....
(ECU) to achieve better performance, whether it be more power, cleaner emissions, or better fuel economy
Fuel efficiency
Fuel efficiency is a form of thermal efficiency, meaning the efficiency of a process that converts chemical potential energy contained in a carrier fuel into kinetic energy or work. Overall fuel efficiency may vary per device, which in turn may vary per application, and this spectrum of variance is...
.
This was done with early engine
Engine
An engine or motor is a machine designed to convert energy into useful mechanical motion. Heat engines, including internal combustion engines and external combustion engines burn a fuel to create heat which is then used to create motion...
computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
s in the 1980s and 1990s. Today, the term chip tuning can be misleading, as people will often use it to describe ECU tuning that does not involve swapping the chip. Modern ECUs can be tuned by simply updating their software through a standard interface, such as OBDII
On Board Diagnostics
On-Board Diagnostics, or OBD, in an automotive context, is a generic term referring to a vehicle's self-diagnostic and reporting capability. OBD systems give the vehicle owner or a repair technician access to state of health information for various vehicle sub-systems...
. This procedure is commonly referred to as engine or ECU tuning. ECUs are a relatively recent addition to the automobile, having first appeared in the late 1970s.
As technology advanced, so did the electronics that go into cars. The ECU in a modern automobile, together with advanced engine technology, makes it possible to control many aspects of the engine's operation, such as spark timing and fuel injection
Fuel injection
Fuel injection is a system for admitting fuel into an internal combustion engine. It has become the primary fuel delivery system used in automotive petrol engines, having almost completely replaced carburetors in the late 1980s....
. The ECU may also control electronic throttle control
Electronic throttle control
Electronic throttle control is an automobile technology which severs the mechanical link between the accelerator pedal and the throttle. Most automobiles already use a throttle position sensor to provide input to traction control, antilock brakes, fuel injection, and other systems, but use a...
(drive-by-wire), valve
Poppet valve
A poppet valve is a valve consisting of a hole, usually round or oval, and a tapered plug, usually a disk shape on the end of a shaft also called a valve stem. The shaft guides the plug portion by sliding through a valve guide...
timing, boost control (in turbocharged
Turbocharger
A turbocharger, or turbo , from the Greek "τύρβη" is a centrifugal compressor powered by a turbine that is driven by an engine's exhaust gases. Its benefit lies with the compressor increasing the mass of air entering the engine , thereby resulting in greater performance...
engines), ABS
Anti-lock braking system
An anti-lock braking system is a safety system that allows the wheels on a motor vehicle to continue interacting tractively with the road surface as directed by driver steering inputs while braking, preventing the wheels from locking up and therefore avoiding skidding.An ABS generally offers...
, the automatic
Automatic transmission
An automatic transmission is one type of motor vehicle transmission that can automatically change gear ratios as the vehicle moves, freeing the driver from having to shift gears manually...
transmission
Transmission (mechanics)
A machine consists of a power source and a power transmission system, which provides controlled application of the power. Merriam-Webster defines transmission as: an assembly of parts including the speed-changing gears and the propeller shaft by which the power is transmitted from an engine to a...
, speed governor (if equipped), and the electronic stability control
Electronic Stability Control
Electronic stability control is a computerized technology that may potentially improve the safety of a vehicle's stability by detecting and minimizing skids. When ESC detects loss of steering control, it automatically applies the brakes to help "steer" the vehicle where the driver intends to go...
system.
Performance gains are realized by adjusting the ignition timing advance. Higher timing may result in higher performance. However, to cope with advanced timing, one must run high-octane gasoline to avoid pre-ignition
Engine knocking
Knocking in spark-ignition internal combustion engines occurs when combustion of the air/fuel mixture in the cylinder starts off correctly in response to ignition by the spark plug, but one or more pockets of air/fuel mixture explode outside the envelope of the normal combustion front.The...
detonation or pinging. Manufacturers design for a specific timing and this may limit performance accordingly.
In addition, changing fuel maps to coincide with the stoichiometric
Stoichiometry
Stoichiometry is a branch of chemistry that deals with the relative quantities of reactants and products in chemical reactions. In a balanced chemical reaction, the relations among quantities of reactants and products typically form a ratio of whole numbers...
ratio for gasoline combustion may also realize performance increase. Most manufacturers tune for optimum emissions and fuel economy purposes which can limit performance.
Cars with a turbo fitted can have the requested and allowable boost levels raised, these applications usually have the most effect if the turbo fitted is a low pressure turbo which leaves the most room for improvement.
Another reason to change the ECU map is if there are engine, intake, or exhaust modifications to the car. These "bolt-on" modifications alter the way that the engine flows, often causing the air to fuel ratio
Air-fuel ratio
Air–fuel ratio is the mass ratio of air to fuel present in an internal combustion engine. If exactly enough air is provided to completely burn all of the fuel, the ratio is known as the stoichiometric mixture, often abbreviated to stoich...
to change. Without re-mapping the fuel tables, some of the performance gains from the modifications may not be realized.
A poorly tuned ECU can result in decreased performance, driveability, and may even cause engine damage.
The most common way to 'upgrade' the ECU is using either plug in modules as mentioned above or using a specialist tuner who will use an OBD Flash tool. These devices generally plug into the diagnostic port although in some cases the reprogramming is done directly on the circuit board
Printed circuit board
A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...
. Maps are supplied by tuners.
An alternative to modifying the on-board chip is adding an external device, often known as a tuning box. The abilities of the external devices generally reflect on-board chip modifications, with the advantage that they can be easily removed to restore the vehicle to standard. Adding an external tuning box is generally only possible on modern engines with external management ports.