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28-848: The Toyota Yaris WRC is a World Rally Car designed by Toyota Gazoo Racing WRT to compete in the World Rally Championship . The car is based on the Vitz-based XP130 Toyota Yaris , and is the first car Toyota have competed with in the WRC since withdrawing from the championship at the end of the 1999 season to focus on their Le Mans Prototype and Formula One programmes. The car was driven by Sébastien Ogier , Elfyn Evans , Ott Tänak , Kalle Rovanperä and Takamoto Katsuta . The car entered its testing and development phase in March 2014, ahead of its début in

56-405: A 33 mm (1.3 in) diameter air restrictor and a maximum boost pressure of 2.5 bar (36 psi) absolute. This limited torque to about 400 N⋅m (300 lb⋅ft) or less ). Exotic materials ( titanium , magnesium , ceramics and composite ) were forbidden except when present in the base model. Carbon fibre and aramid fibre were very restricted ("only one layer of fabric

84-482: A 34 mm diameter air restrictor before the turbocharger inlet, limiting the airflow to about 10 cubic meters per minute. The restriction was intended to limit power output to 220 kW (300 hp) although some WRC engines were believed to produce around 250–250 kW (330–340 hp). Engine development did not focus on peak power output but towards producing a very wide powerband (or power curve). Typically, power output in excess of 220 kW (300 hp)

112-855: A linear system), so peak power is produced in the upper speed range where there's both high torque and high RPM. In turbocharged and supercharged engines with potential for abundant torque, an intake pressure regulation system often limits torque to a near-constant figure across the engine speed range to reduce stresses on the engine and provide consistent handling without decreasing peak power. Powerbands can surpass 14,000 RPM in motorcycles and some racing automobiles, such as Formula One cars . Such high speeds are reached by using lightweight pistons and connecting rods with short strokes to reduce inertia, and thus stresses on parts. Advances in valve technology similarly reduce valve float at such speeds. As an engine grows larger (its stroke in particular), its power band moves to lower speeds. In more common applications,

140-510: A modern, well designed and engineered fuel-injected , computer-controlled , multi-valve and optionally variable-valve timing -equipped gasoline engine using good fuel can achieve remarkable flexibility in automobile applications, with sufficient torque even at low engine speeds and a relatively flat power output from 1,500 to 6,500 RPM, allowing easy cruising and forgiving low-speed behaviour. However, achieving maximum power for strong acceleration or high road speed still requires high RPM. Though

168-433: A power-splitting device such as a clutch or torque converter to efficiently achieve a wide range of speeds. A continuously variable transmission can also avoid the issues of a narrow power band by keeping the engine running at an optimal speed. In typical combustion engines found in vehicles, the torque is low at idling speed, reaches a maximal value between 1,500 and 6,500 RPM, and then falls more or less sharply toward

196-405: Is produced, and ends below the redline after reaching maximum power (above 5,000 RPM but less than 7,000 RPM). Diesel engines in cars and small trucks may develop maximum torque below 2,000 RPM with the power peak below 5,000 RPM. A mechanical transmission with a selection of different gear ratios is designed to make satisfactory power available over the full range of vehicle speeds. The goal of

224-417: Is used and is affixed to the visible face of the part"), except for bodywork's side protections where multiple layers of aramid fibre were allowed. The gear changes must be made with a mechanical linkage system, so paddle-shifters were outlawed. However the system was re-allowed in 2015 . There was no center differential (earlier it used to be 3 differentials, with a center/3rd differential included), but

252-561: The 2017 season . Development and operation of the cars would be overseen by four-time World Drivers' Champion Tommi Mäkinen , and entered under the banner of Toyota Gazoo Racing WRT . The car made its first public appearance in May 2016 during testing in Palokka-Puuppola , with Mäkinen and Juho Hänninen driving. The Toyota Gazoo Racing three car team of Toyota Yaris WRCs won the 2018 manufacturers' championship, followed in 2019 by

280-449: The engine displacement up to 2.0L, forced induction (including an anti-lag system ), addition of four wheel drive , fitment of a sequential gearbox , modified suspension layout and attachment points, aerodynamic body modifications, weight reduction to a minimum of 1230 kg and chassis strengthening for greater rigidity. The maximum width was set at 1770 mm while front and rear tracks shouldn't exceed 1550 mm. Unlike

308-444: The changing of some parts, including suspension, steering, turbochargers, and gearboxes. Starting in 2011, rules for WRC cars changed to be more restrictive. New regulations were derived from Super 2000 cars with a different aerodynamic kit. The cars could be smaller models (there was no longer a minimum 4 m length) and include a custom-build or production 1600 cm direct injection turbo-charged global race engine with

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336-517: The cost of lower efficiency). While engines and motors have a large range of operating speeds, the power band is usually a much smaller range of engine speed, only half or less of the total engine speed range (electric motors are an exception—see the section on electric motors below). Specifically, power band is the range of RPM around peak power output. The power band of an internal combustion gasoline automobile engine typically starts at midrange engine speeds (around 4,000 RPM) where maximum torque

364-404: The literal power band covers most of the operating RPM range, particularly in first gear (as there is no lower gear to shift down to, and no "flat spot" in which the engine does not produce any power), the effective band changes in each gear, becoming the range limited at the upper end by either the limiter, or a point roughly located between peak power and the redline where power drops off, and at

392-487: The lower end the engine's idling speed. A typical road-going ("high-speed") diesel has a narrower band, generating peak torque at lower RPM (often 1,500–2,000 RPM) but also with a sharper fall-off below this, and reaching peak power around 3500-4500 RPM, again rapidly losing strength above this speed. Turbocharged diesel engines with turbo lag (narrowed, exaggerated power band intrinsic to most turbocharged engines) may display this characteristic even more markedly. Therefore,

420-678: The manufacturer's (or purchaser's/modifier's) choice of gearing, and appropriate use of the available ratios, is even more crucial to make best use of the available power and avoid being "bogged down" in flat spots. Larger diesel engines in locomotives and some watercraft use diesel-electric drives. This eliminates the complexities of extremely low gearing, as described below. The largest ("low-speed") diesels—large generators on land and marine diesels at sea—may turn at only hundreds of RPM or even below, with idling speeds of 20-30 RPM. These engines are usually two-stroke diesel engines . Electric motors are unique in many ways, especially when it comes to

448-424: The maximum width of the WRC cars was increased from 1770 mm to 1800 mm. In an attempt to cut costs, since 2006 new regulations required mechanical front and rear differentials, while the central differential remained active. Active suspension and water injections were also prohibited. Cars entered by a manufacturer had to be equipped with the same engine for two rallies; further limitations were imposed on

476-404: The new World Rally Cars were allowed for use by manufacturers' teams only. Powerband The power band of an internal combustion engine or electric motor is the range of operating speeds under which the engine or motor is able to output the most power , that is, the maximum energy per unit of time. This usually means that maximum acceleration can be achieved inside this band (often at

504-461: The new regulation allows the only front and rear axle differential and a mechanical clutch to disconnect the rear axle during handbrake use (to reduce cost and make the cars' driving style more exciting again for both spectators and TV broadcasts). These two differentials must be mechanical, without electronic control or hydraulic or viscous systems (from 2006 to 2010 the center differential and previously all three could be active ). The minimum weight

532-510: The power band. The exact characteristics vary greatly with the type of electric motor. The maximum torque of a universal motor (vacuum cleaner, small machines, drills, starter motors) occurs at zero rotation rate (when stalled) and falls for higher RPM. For induction motors connected to a fixed frequency AC source (most common in large applications), the maximum torque is usually just below the synchronous RPM, sinks to zero for this RPM and becomes negative above it (induction generator); at low RPM

560-535: The redline. Below the RPM of maximal torque, the intake air velocity and thus mixing of air and fuel is not ideal. Above this speed several factors start to limit the torque, such as growing friction, the required time for closing the valves and combustion, and insufficient intake flow. Due to increasing vibration and heat, an external RPM limitation may also be installed. Power is the product of torque multiplied by speed of rotation (analogous to force multiplied by speed in

588-534: The requirements for the preceding Group A cars, manufacturers were no longer required to build "homologation specials" in order to meet approval. The base model did not need to have all the characteristics of the WRC car, as evidenced from cars such the Peugeot 206 , 307 , Citroën Xsara , and Škoda Fabia , which during this period had no road car variant with a turbocharged petrol engine or four-wheel-drive. To limit power, all forced induction cars were fitted with

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616-410: The selection of gear ratios is to keep the engine operating in its power band. The narrower the band, the more gears are needed, closer together in ratio. By careful gear selection, an engine can be operated in its power band, throughout all vehicle speeds. Such use prevents the engine from labouring at low speeds, or exceeding recommended operating speeds. A narrow power band is often compensated for by

644-539: The team's Ott Tänak and Martin Järveoja winning the 2019 drivers' and co-drivers' championships, the 2020 drivers' (Ogier) and co-drivers' ( Julien Ingrassia ) championships, and a sweep of the 2021 manufacturers', drivers' (Ogier) and co-drivers' (Ingrassia) championships. A successor known as the Toyota GR Yaris WRC , based on the 2020 GR Yaris road car, was due to be introduced in 2021 but

672-706: The torque is usually slightly lower. Synchronous motors can be used only at the AC source synchronous velocity. In modern applications, synchronous and induction motors with electronic control of the frequency are used, e.g., brushless DC electric motors . In this case, unless external limitations are applied, the maximum torque is achieved at low RPM. For example, the AC motor found in the Tesla Roadster (2008) produces near constant maximum torque from 0 to about 6000 RPM, while maximum power occurs at about 10000 RPM, long after torque begins to drop off. The Roadster's redline

700-445: Was 1200 kg empty and 1350 kg (1360 kg from 2013) with driver and co-driver (in both cases when measured with only one spare wheel ). The 1.6 L turbo-charged global race engine was retained in the 2017 World Rally Car regulations, but the turbo restrictor diameter was increased from 33 mm to 36 mm, increasing the engine's power output from 230 to 280 kW (310 to 380 hp). The minimum empty vehicle weight

728-453: Was available from 3000 rpm to the 7500 rpm maximum, with a peak of 250–250 kW (330–340 hp) at around 5500 rpm. At 2000 rpm (the engine idle speed in "stage" mode) power output was slightly above 150 kW (200 hp). By 2004, the best cars had ABS , electronic clutch control, paddle-shift , traction control , three active differentials , ride height control with GPS, electronic dampers and active suspension . For 2005

756-471: Was decreased by 10 kg but the combined vehicle, crew and spare wheel weight remained at 1360 kg. Manufacturers were given more freedom to maximise aerodynamic performance, including large brake cooling ducts in fairings forming enlarged wheel arches. Electronically controlled active centre differentials were permitted, while the front and rear differentials remain mechanical. While 2011 specification World Rally Cars were allowed to compete in 2017,

784-535: Was later decided against in favour of sticking with the existing rally car. The Yaris WRC's true successor, the Toyota GR Yaris Rally1 , would not be racing until the year after . * Season still in progress. World Rally Car Between 1997 and 2010, the regulations mandated that World Rally Cars must have been built upon a production car with a minimum production run of 2500 units. A number of modifications could be made including increasing

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