Editing Formula SAE (section)

==Summary of rules==

===Student competition===

Formula SAE has relatively few performance restrictions. The team must be made up entirely of active college students (including drivers) which places obvious restrictions on available work hours, skill sets, experience, and presents unique challenges that professional race teams do not face with a paid, skilled staff. This restriction means that the rest of the regulations can be much less restrictive than most professional series.

Students are allowed to receive advice and criticism from professional engineers or faculty, but all of the car design must be done by the students themselves. Students are also solely responsible for fundraising, though most successful teams are based on curricular programs and have university-sponsored budgets. Additionally, the points system is organized so that multiple strategies can lead to success. This leads to a great variety among cars, which is a rarity in the world of motorsports.

===Engine (IC Competition)===
The engine must be a [[four-stroke]], [[Otto cycle|Otto-cycle]] piston engine with a displacement no greater than 710cc. An [[air restrictor]] of circular cross-section must be fitted downstream of the throttle and upstream of any [[forced induction|compressor]], with a diameter no greater than 20mm for gasoline engines, forced induction or naturally aspirated, or 19mm for ethanol-fueled engines. The restrictor keeps power levels below 100&nbsp;hp in the vast majority of FSAE cars. Most commonly, production four-cylinder 600cc [[sport bike]] engines are used due to their availability and displacement.  However, there are many teams that use smaller [[V-twin]] and [[single-cylinder]] engines, mainly due to their weight-saving and packaging benefits. Very rarely do teams build an engine from scratch, few examples include [[Western Washington University]]'s 554cc V8 entry in 2001, [[University of Melbourne]]'s "WATTARD" engine in 2003–2004, and [[University of Auckland]]'s V twin.  In 2019, 120 student teams registered for competition, and 109 of them were found to be onsite. There was also 2567 students that participated from these teams that showed up.<ref>{{Cite web |title=About - Formula SAE Knowledge |url=https://www.sae.org/attend/student-events/formula-sae-knowledge/about |access-date=2025-03-12 |website=www.sae.org |language=en}}</ref>

=== Electric Powertrain (EV Competition) ===
[[File:Carnegie Mellon Racing2 4e.jpg|thumb|258x258px|[[Carnegie Mellon University]]'s Formula SAE Electric Car, 24e]]
The accumulator must not have a voltage greater than 600V, but does not have a capacity limit. An energy meter is installed at competition ensuring no more than 80kW are drawn. Most teams elect to use lithium-ion cells, but both lead acid cells as well as other energy storage devices such as capacitors are also permitted — this accounts for the commonly referred ''battery pack'' being referred to as an ''accumulator'' in this competition. Cell voltages and temperatures must be monitored and individual cell connected via fusible links. These challenges lead many (especially young) teams to use preconfigured cell modules that are connected together in the accumulator enclosure. The competition organizers attempt to prepare teams for competition EV technical inspection by having teams complete an Electrical Safety Form (ESF) prior to competition — this form outlines many of the parts used in the high voltage system as well as design decisions the team is making.

===Suspension===
The suspension is unrestricted save for safety regulations and the requirement to have 50mm total of wheel travel. Most teams opt for four-wheel [[independent suspension]], almost universally [[double-wishbone]]. Active suspension is legal.

===Aerodynamics===
Complex aerodynamic packages, while not required to compete, are common among the fastest teams. With the low speeds of the FSAE competition rarely exceeding {{cvt|60|mph|km/h}}, designs must be thoroughly justified in the design judging event through [[wind tunnel]] testing, [[computational fluid dynamics]], and on track testing. Aerodynamic devices are regulated through maximum size and powered aerodynamic devices are outlawed.

===Weight===
There is no weight restriction. The weight of the average competitive Formula SAE car is usually less than {{convert|440|lb|abbr=on}} in race trim. However, the lack of weight regulation combined with the somewhat fixed power ceiling encourages teams to adopt innovative weight-saving strategies, such as the use of composite materials, elaborate and expensive machining projects, and [[rapid prototyping]]. In 2009 the fuel economy portion of the endurance event was assigned 100 of the 400 endurance points, up from 50. This rules change has marked a trend in [[engine downsizing]] in an attempt to save weight and increase fuel economy. Several top-running teams have switched from high-powered four-cylinder cars to smaller, one- or two-cylinder engines which, though they usually make much less power, allow weight savings of {{convert|75|lb|abbr=on}} or more, and also provide much better fuel economy. If a lightweight single-cylinder car can keep a reasonable pace in the endurance race, it can often make up the points lost in overall time to the heavier, high-powered cars by an exceptional fuel economy score. 
:'''Example:''' At the 2009 Formula SAE West endurance event, third-place finishers [[Rochester Institute of Technology]] completed the endurance course in 22 minutes, 45 seconds with their four-cylinder car, while fourth-place finishers [[Oregon State University]] finished in 22 minutes, 47 seconds with their single-cylinder car; this gave RIT 290.6 of 300 points for the race portion of the event and OSU 289.2 points. However, OSU used the least fuel of any car ({{convert|.671|USgal|L|abbr=on}}, or {{convert|20.3|mpgus|L/km|abbr=on}} over the entire endurance race) and received the full 100 points for fuel economy, while RIT used {{convert|1.163|USgal|L|abbr=on}} ({{convert|11.75|mpgus|L/km|abbr=on}}) and was thus only awarded 23.9 of the available points. RIT went on to win the overall competition by only 8.9 points over OSU, having scored slightly better in all of the other dynamic events.<ref>{{Cite web |url=http://www.sae.org/students/fsaew2009results.pdf |title=Archived copy |access-date=2010-03-31 |archive-url=https://web.archive.org/web/20110605035925/http://www.sae.org/students/fsaew2009results.pdf |archive-date=2011-06-05 |url-status=dead }}</ref>

===Safety===
The majority of the regulations pertain to safety. Cars must have two steel [[roll hoop]]s of designated thickness and alloy, regardless of the composition of the rest of the chassis. There must be an [[impact attenuator]] in the nose, and impact testing data on this attenuator must be submitted prior to competing. Cars must also have two hydraulic brake circuits, full five-point racing harnesses, and must meet geometric templates for driver location in the cockpit for all drivers competing. Tilt-tests ensure that no fluids will spill from the car under heavy cornering, and there must be no line-of-sight between the driver and fuel, coolant, or oil lines. Electric vehicles are also fitted with a ''Shutdown Circuit'', which is the physical electrical path the current takes that closes the main contactors of the vehicle. All safety buttons, switches, and circuits are part of the Shutdown Circuit such that removing any should make it physically impossible for high voltage to be present outside the accumulator.