Editing Car tuning (section)

===Engine tuning===
{{main|Engine tuning}}
[[File:Turbo-p1020673.jpg|thumb|A cutaway of a [[turbocharger]], used to increase the performance of an engine]]
Engine tuning is the process of modifying the operating characteristics of an engine. In a typical engine set-up, there are various mechanical and electronic elements such as the [[Inlet manifold|intake manifold]], [[Spark plug|spark plugs]], and [[Mass flow sensor|mass air flow sensor]]. Modern engines employ the use of an [[engine control unit]] to provide the best balance between performance and [[Exhaust gas|emissions]]. Via the [[On-board diagnostics|OBD]] communications protocol,<ref>{{Cite web|last=Miller|first=Tim|date=November 1, 2021|title=OBD2 Communication Protocols|url=https://www.obdadvisor.com/obd2-protocol-supported-vehicle/|url-status=live|website=OBD Advisor|archive-url=https://web.archive.org/web/20180103101443/http://www.obdadvisor.com:80/obd2-protocol-supported-vehicle/ |archive-date=2018-01-03 }}</ref> electronically controlled aspects of the engine can be modified in a process known as mapping. Mapping can either be performed by changing the software within the ECU ([[chip tuning]] via firmware modification), or by providing false data via plug-in hardware. Other standalone engine management systems are available; these systems replace the factory computer with one that is user-programmable. Engine tuning often involves the use of a [[dynamometer]] in order to provide, base-line performance and post tuning metrics.<ref>{{cite web | access-date=November 12, 2023 | url=https://labordemotorsport.com/the-fascinating-history-of-dyno-tuning/ | title=The Fascinating History of Dyno Tuning | date=September 19, 2023 | last=Joshua | first=Laborde | url-status=live | website=Laborde Motorsport | archive-url=https://web.archive.org/web/20231112092650/https://labordemotorsport.com/the-fascinating-history-of-dyno-tuning/ | archive-date=12 November 2023}}</ref>

Mechanical components of the [[Internal combustion engine|engine]] can also be added or replaced, such as [[forced induction]] systems like [[Turbocharger|turbochargers]] or [[Supercharger|superchargers]].

Improper, incorrect and poorly executed engine modifications can have a detrimental effect on performance and reliability. Mechanical and electrical components can suffer or simply fail as a result. An example would be the use of an air compressor such as a turbocharger to increase the volume of air used in the power stroke of the [[Otto cycle]]. In a typical chemical reaction, the [[air–fuel ratio]] must be a minimum of 14:1. If higher ratios are used, higher pressures and temperatures are observed in the cylinders,<ref>{{Cite web|title=What Is a Cylinder in a Car?|url=https://www.kia.com/dm/discover-kia/ask/what-is-a-cylinder-in-a-car.html|access-date=2021-11-23|website=Kia Motors British Dominica|language=en}}</ref> which can quickly push an engine beyond its intended design limits.

Neglecting such operating parameters can lead to premature failures, such as warped cylinder heads and walls, disintegrated [[Piston ring|piston rings]], cracked or bent [[Connecting rod|connecting rods]] and [[Crankshaft|crankshafts]], total [[Internal combustion engine cooling|cooling system]] failure, [[Firing order|engine fire]]{{clarify|date=February 2025|reason=unrelated link target?}}, [[engine knocking]], engine seizing, and even blowouts. This can all lead to very expensive repairs, as well as being very dangerous.