# Using a fuel with higher oxygen content or by adding an oxidizer such as nitrous oxide.
# Reducing losses to friction by machining moving parts to lower tolerances than would be acceptable for production, or by replacing parts. A common example of this is, in OHV engines, replacing the production rocker arms with replacements incorporating roller bearings in the roller contacting the valve stem.
# Reducing the “rotating mass”, which comprises the crankshaft, connecting rods, pistons, and flywheel. Doing so can improve throttle response due to lower inertia, as well as reduce overall vehicle weight. This may be achieved by using alloy parts instead of steel. However a heavy crankshaft can void the need for a flywheel (common on V6 engines).
# Changing the tuning characteristics electronically, by changing the firmware of the engine management system (EMS). This chip tuning often works because modern engines are designed to produce more power than required, which is then reduced by the engine management system to make the engine operate smoothly over a wider RPM range, with low emissions. This is called de-tuning and produces long-lasting engines and the ability to increase power output later for facelift models. Recently emissions have played a large part in de-tuning, and engines will often be de-tuned to produce a particular carbon output for tax reasons.
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 computers 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.