Partager la publication "Dodge//SRT Demon : 840hp supercharged 6.2L HEMI V8 Fastest 0-60mph 2.3s #NYIAS2017"
Après des mois de teasers, Dodge a présenté l’ultime Challenger SRT dénommé Demon, à la veille de l’ouverture du New York Auto Show 2017. Les spécifications pour ce monstre sont démoniaques : 6.2L supercharged V8 delivers 840 hp & 770 lb-ft, making the Demon the most powerful muscle car ever. It also has the highest horsepower from a V8 production car. It dispatches 30 mph in 1 second; 60 mph takes just 2.3 seconds.
April 11, 2017 – Auburn Hills, Mich. – Dodge rocked the high-performance car world in 2014 with the 707-horsepower Charger SRT Hellcat and Challenger SRT Hellcat, building supercar performance at affordable prices. They were the most powerful muscle cars ever – until now.
Today, Dodge is shaking the foundation of the entire performance car industry, launching New York International Auto Show week with its wickedly fast new 2018 Dodge Challenger SRT Demon – highly capable on the street, absolutely dominating at the drag strip.
Powered by a 840-horsepower, supercharged 6.2-liter HEMI Demon V-8, the limited-production Challenger SRT Demon is the world’s most powerful factory-production V-8 – bar none. (National Hot Rod Association) NHRA-certified 9.65 seconds @ 140 mph makes the Dodge Challenger SRT Demon the fastest ¼-mile car in the world.
0-30 mph: 1.0 second
0-60 mph: 2.3 seconds
The Challenger SRT Demon also is the world’s first production car to lift the front wheels at launch and set the world record for longest wheelie from a standing start by a production car at 2.92 feet, certified by Guinness World Records. And hold onto your seat. The Challenger SRT Demon also registers the highest g-force (1.8 g) ever recorded at launch in a production car.
“With Demon, our goal was to build a car that would tattoo the Dodge logo into the subconscious of the general market, beyond even our loyal enthusiasts. To do so, we had to set records that have never been set before, do more than has ever been done before, go beyond even the legendary Hellcat. The result: an 840-horsepower, 9-second muscle car unlike anything that has ever come before it.”
Tim Kuniskis, Head of Passenger Cars – Dodge, SRT, Chrysler and FIAT, FCA North America
The Challenger SRT Demon’s record-setting performance is the result of collaboration among the Dodge//SRT, Design, Engineering, Powertrain and Manufacturing teams inside FCA US LLC, many of whom are experienced and active drag racers. While the 2018 Dodge Challenger SRT Demon remains a potent street car, every component was scrutinized and optimized for weight, capability and durability on the strip.
Demon Unleashed – Dodge Challenger SRT Demon
The new 2018 Dodge Challenger SRT Demon is the most-powerful muscle car ever with 840 horsepower and 770 pounds-feet of torque from its supercharged 6.2-liter HEMI® Demon V-8 engine.
Moteur Dodge Demon
Avec un V8 surchargé de 6,2 litres et une carrosserie à propos de l’aérodynamique que l’usine de cette voiture, le SRT Demon est la première voiture de production d’usine avec un ordinateur de commande de moteur spécialement étalonné pour un indice d’octane de 100.
Sur la Dodge SRT Demon, Après avoir fait le plein, un bouton au tableau de bord modifie les paramètres de la gestion électronique moteur (en premier lieu, l’avance à l’allumage), et le moteur fournit plus de puissance.
La puissance est transmise aux roues arrière via une boîte automatique à huit rapports et accompagnée d’une fonction TransBrake qui verrouille l’essieu arrière, bloquant ainsi tout mouvement de l’auto. Cela permet d’augmenter le régime moteur à l’arrêt et d’optimiser au maximum les accélérations afin de garantir un départ canon. Et comme si cela ne suffisait pas, Dodge annonce que la voiture possède même un système de précharge de couple qui améliore le travail du compresseur pour alimenter encore davantage le moteur en air. L’ensemble de ce système est, toujours selon la marque américaine, plus efficace de 30% par rapport à la fonction launch control.
Basé sur une version Hellcat de 707 ch., ce coupé en conserve le V8 6.2L suralimenté par compresseur. Mais Dodge fait grimper la cavalerie à 808 ch avec du carburant d’octane 91, et à 840 ch avec un octane supérieur à 100 !
L’indice d’octane mesure la résistance d’un carburant utilisé dans un moteur à allumage commandé à l’auto-allumage (allumage sans intervention de la bougie). Ce carburant est très généralement l’essence. On dit qu’un carburant a un indice d’octane de 95 par exemple, lorsque celui-ci se comporte, au point de vue auto-allumage, comme un mélange de 95 % d’iso-octane qui est résistant à l’auto-inflammation (son indice est de 100 par définition) et de 5 % de n-heptane, qui lui s’auto-enflamme facilement (son indice est de 0 par définition).
L’octane est le principal composé de l’essence exprimé en %. L’essence « normale » a un indice d’octane de 91 aux États-Unis et 95 en Europe (SP95 ou Eurosuper) ou 98 avec le fameux SP98). A savoir, le plomb était un additif utilisé dans l’essence comme lubrifiant (au niveau des soupapes) et afin d’améliorer l’indice d’octane du carburant. Le plomb a été depuis remplacé par du Potassium. L’indice d’octane permet de repousser l’auto-allumage et de mieux contrôler son déclenchement.
Les indices, en France, sont :
Super 97, avec du plomb – indice d’octane de 97.
Sans plomb 98 – indice d’octane de 98 – 98% d’octane et 2% d’heptane.
Sans plomb 95 – indice d’octane de 95 – 95% d’octane et 5% d’heptane.
En Formule 1, le carburant utilisé est bien du Sans Plomb (le même que celui de notre pompe à essence) mais pour lequel l’indice d’octane n’est pas limité et les écuries peuvent déterminer le rendement le plus adapté à leur motorisation… en bref les ingrédients sont donc réglementés par la FIA mais pas les proportions.
Un carburant à haut indice d’octane n’est pas en soi un carburant à haute teneur en énergie, il rend simplement le moteur pour lequel il est conçu thermodynamiquement plus efficace. Utiliser un carburant à plus haut indice d’octane que celui pour lequel le moteur est conçu n’en augmente pas le rendement : chaque moteur nécessite le carburant ayant l’indice d’octane correspondant à son fonctionnement optimal.
Demon’s heart: Supercharged V-8
The heart of the 2018 Dodge Challenger SRT Demon is the supercharged 6.2-liter HEMI Demon V-8, rated at 840 horsepower and 770 pounds-feet of torque (1044 Nm).
While the Demon V-8 shares its architecture with the 707-hp 6.2-liter supercharged HEMI Hellcat V-8, it is not simply a Hellcat engine with more boost. The Demon V-8 engine has 25 major component upgrades from the Hellcat engine, including supercharger, pistons, rods, valve train and fuel injection system.
Among the changes, compared with the Hellcat V-8, the Demon’s supercharged V-8 features:
Larger supercharger: 2.7 liters versus 2.4 liters
Increased boost pressure: 14.5 psi versus 11.6 psi
Higher rpm limit: 6,500 rpm versus 6,200 rpm
Fuel: Two dual-stage fuel pumps versus one
Larger induction air box with three sources of intake air: Air-Grabber hood, driver-side Air-Catcher headlamp and an inlet near the wheel liner
In addition, the HEMI Demon V-8 includes a high-speed valvetrain, strengthened connecting rods and pistons, and improved lubrication system. The upgrades enable the engine to sustain higher output and pressures while meeting FCA US LLC’s stringent durability requirements.
One key to the Challenger SRT Demon’s best-ever power output is air – the supercharged Demon V-8 takes in plenty of it. The SRT Demon’s Air-Grabber™ hood includes the largest functional hood scoop (45.2 square inches) of any production car.
The Air-Grabber hood is sealed to the air box, which is also fed from the driver-side Air-Catcher™ headlamp and an inlet near the wheel liner. Combined, those sources give the Demon V-8 an air-flow rate of 1,150 cubic feet per minute, 18 percent greater than the Hellcat V-8 and the largest air induction volume of any production car.
The additional air inlets help reduce the temperature of the intake air by more than 30 degrees Fahrenheit compared with the Hellcat V-8, which improves overall throttle response.
Heat is the enemy of speed at the drag strip, so Dodge//SRT engineers looked for more ways to keep the intake air as close to the optimum temperature as possible.
The innovative SRT Power Chiller is a production car first. It diverts the air-conditioning refrigerant from the SRT Demon’s interior to a chiller unit mounted by the low-temperature circuit coolant pump. Charge air coolant, after being cooled by ambient air passing through a low-temperature radiator at the front of the vehicle, flows through the chiller unit, where it is further cooled. The chilled coolant then flows to the heat exchangers in the supercharger.
Every run down the drag strip generates plenty of heat. The After-Run Chiller, a factory-production car first, helps the SRT Demon get ready for the next run as quickly as possible.
When the engine is shut down, the After-Run Chiller keeps the engine cooling fan and low-temperature circuit coolant pump running to lower the supercharger/charge air cooler temperature, helping the Challenger SRT Demon minimize heat soak effects. The driver can track the supercharger coolant temperature on the 8.4-inch Uconnect touchscreen in the instrument panel, and know in real time when the supercharger is at the optimum temperature for another run.
The impact of the SRT Power Chiller and After-Run Chiller, combined, lowers intake air temperature by up to 45 degrees Fahrenheit.
Fueling performance: 100+ unleaded high octane
The Challenger SRT Demon is the first-ever, street-legal factory-production car designed to run on 100+ unleaded high-octane fuel. That fuel is readily available at select gas stations, specialty shops and drag strips.
The keys to unleashing the SRT Demon’s full performance fury are in the Demon Crate: Direct Connection Performance Parts include a new powertrain control module calibrated for the high-octane unleaded fuel and a new switch bank for the center stack that includes a high-octane button.
The SRT Demon leaves the factory with a powertrain control module configured for 91-octane premium unleaded pump gasoline, which delivers top level performance.
The switch to the Direct Connection controller enables the supercharged HEMI engine to extract the maximum power from the knock-resistant fuel at high pressures and optimum spark timing. Drag racers can anticipate improvements in elapsed times (ETs) and trap speeds with the high-octane fuel.
The Challenger SRT Demon is engineered to be able to run on a mix of 100+ octane and premium unleaded fuels without hurting the engine, but the high-octane function won’t activate if the combined fuel octane is too low. A message in the gauge display tells the driver the car will use the premium fuel calibration until the engine is shut off and restarted. How does the car know? The controller monitors the engine’s knock sensors.
There will be plenty of fuel available: the SRT Demon carries dual fuel pumps (versus one pump in the Challenger SRT Hellcat), larger fuel injectors and fuel lines that handle higher pressures.
Similar to the Challenger SRT Hellcat, the SRT Demon comes with two key fobs. The black fob limits engine output to 500 horsepower. The red key fob unlocks the engine’s full output of 808 horsepower and 717 pounds-feet torque. With either key fob, the driver can activate Eco and Valet Modes. Eco Mode revises the transmission shift schedule to include second-gear starts. Valet Mode limits the engine to 4,000 rpm and reduces torque output.
The high-octane unleaded fuel capability with the optional Direct Connection powertrain controller boosts engine output to 840 horsepower and 770 pounds-feet of torque.
Châssis Dodge Demon
TransBrake is a production car first
Every Dodge Challenger SRT Demon is equipped with the standard TorqueFlite 8HP90 eight-speed automatic transmission. Already a proven and robust gearbox used with the HEMI Hellcat V-8, the transmission gets some significant changes for duty in the Challenger SRT Demon.
Internal changes include an upgraded torque converter that delivers an 18 percent increase in torque multiplication. Also, the stall speed is increased 11 percent and the lockup speed is increased.
The Challenger SRT Demon is the first-ever, factory-production car with TransBrake, which locks the transmission output shaft to hold the car in place before a standing start. This lets the driver increase engine speed up to 2,350 rpm without overpowering the brakes, resulting in quicker power delivery and up to 15 percent more torque at launch.
Driver-oriented step-by-step instructions are displayed on the instrument cluster to guide the driver through the staging process and help them keep their focus on the Christmas Tree.
The TransBrake helps to improve driver reaction time and launch consistency by using the steering wheel paddle shifters as a launch trigger – a paddle launch improves reaction time by 30 percent compared with a foot-brake launch. In addition, the system enables delivery of initial torque to the flywheel as soon as 20 milliseconds after launch.
TransBrake works in conjunction with another SRT Demon first-ever factory-production car feature, Torque Reserve, to deliver increased levels of power and torque at launch.
Torque Reserve becomes active once engine speed passes 950 rpm. It does two things:
Closes the bypass valve, “prefilling” the supercharger with boost
Manages fuel flow to cylinders and manages spark advance or retard to balance engine rpm and torque
With TransBrake and Torque Reserve active, the SRT Demon has more than 8 psi of boost at launch and up to 120 percent more engine torque than without Torque Reserve. TransBrake also preloads the driveline with torque, leading to full engine torque delivery at the rear wheels 150 milliseconds after the shift paddle is released. That results in faster acceleration at launch, faster 60-foot times and an improvement of more than a tenth of a second in quarter-mile times, which can be an entire car length.
Driveline components have been upgraded to get all that power and torque to the rear wheels, on every run.
Production car first: Drag-mode Launch Assist
SRT engineers went digital to isolate and resolve one of the biggest challenges to clean launches and driveline integrity – wheel hop.
In simple terms, wheel hop happens when tires quickly slip and regain traction at launch, rapidly storing up and releasing energy in the driveline. These high torque spikes can quickly and severely damage driveline components – and up until now, the only solution was to back out of the throttle.
Not with the Challenger SRT Demon. In a first for a factory-production car, the SRT Demon’s Launch Assist uses the wheel speed sensors to watch for signs that the tires are slipping/sticking. If slip is detected, the SRT Demon’s control module momentarily reduces engine torque to maximize traction almost instantly – without the driver having to lift. Launch Assist reduces loads in the driveline from wheel hop by more than 15-20 percent, dramatically reducing component damage.
Production car first: Street-legal drag tires
The Challenger SRT Demon is equipped with a set of four standard Nitto NT05R street-legal, drag-race tires, a first for a factory-production car.
The 315/40R18 tires were specifically designed and developed exclusively for the SRT Demon, with a new compound and specific tire sidewall construction. The drag radials give the SRT Demon a 15-percent larger tire contact patch and more than twice the grip of the Challenger SRT Hellcat.
The sticky drag tires are mounted on lightweight 11×18-inch wheels, with each tire measuring 12.6 inches wide. Putting full-size tires at all four corners gives drag racers an extra set of rear tires when the front tires are replaced with narrow front-runners at the track.
A unique rear knuckle reduces negative camber by 0.5 degrees, “standing up” the tire and increasing the size of the tire contact patch.
Engineering: More traction, less weight
The main mission of the 2018 Dodge Challenger SRT Demon is to cover the quarter mile as quickly as possible. To do this, it combines the best of both mechanical and electronic tuning to deliver maximum launch grip while still maintaining precision directional control.
The Bilstein Adaptive Damping shocks have been tuned for drag racing, shifting as much weight as possible on the rear tires at launch for maximum traction. The weight transfer improves rear tire grip by 11 percent.
Mechanically, weight shift in the Challenger SRT Demon is aided by softening up some key suspension components.
Those changes, compared with the Challenger SRT Hellcat, include:
Softer springs: 35 percent lower rate front/28 percent lower rate rear
Softer, lighter, hollow sway bars: 75 percent lower rate front/44 percent lower rate rear
When Drag Mode is activated, the front Bilstein shocks are set for firm compression and soft rebound damping, while the rear Bilstein shocks are set for firm compression and firm rebound damping.
That configuration is maintained as long as the car runs at wide open throttle. When the driver backs off the gas pedal, the system switches to firm compression and firm rebound front and rear for improved handling.
Also during Drag Mode, the traction control system is disabled to enable the rear wheels to spin for a burnout, but the electronic stability control system remains engaged to help the driver with straight-line performance.
In pursuit for every tenth of a second, engineers looked to cut as much weight as possible. The result: Equipment removed from the Challenger SRT Demon weighs more than 200 pounds.
Design Dodge Demon
Dual personalities: Performance Pages and Drive Modes
The 2018 Dodge Challenger SRT Demon gives the driver the capability to set up the car for on-road precision, maximum drag strip performance or anything in between.
The nerve center for those personalities is SRT Performance Pages and Drive Modes, displayed on the Uconnect 8.4-inch touchscreen.
Performance Pages arm the driver with real-time data, including a graphic display of engine horsepower and torque with gear changes plotted; supercharger coolant temperature; timers for reaction time, 0-60 miles per hour (mph), 0-100 mph, eighth-mile and quarter-mile elapsed time and vehicle speed; instantaneous and peak longitudinal and lateral g-forces; and gauge readouts for engine oil temperature and pressure, coolant temperature, transmission fluid temperature, intake air temperature, air-fuel ratio; intercooler coolant temperature, boost pressure and battery voltage.
The Drive Modes include the Challenger SRT Demon-exclusive Drag Mode. Drive Mode settings include Auto (Street) Mode, which sets the Bilstein Adaptive Damping Suspension (ADS) for comfortable ride with compliant handling, and Custom Mode, which lets the driver select between Auto and Drag Mode configurations for the transmission, paddle shifters, traction, suspension and steering.
Performance Pages also includes rpm-adjustable launch control and by-individual-gear-adjustable shift light displayed in the instrument cluster. A new data recorder feature lets the Challenger SRT Demon driver build an archive of data to help optimize the car for track and weather conditions, while helping to improve driving techniques.
Functional and Intimidating Design
The 2018 Dodge Challenger SRT Demon is the widest Challenger ever and first-ever, factory-production muscle car with wide-body fender flares.
The wide body flares are designed to amplify the Challenger SRT Demon’s menacing stance, while making room for wider tires with concealed attachments. The fender flares, which cover the lightweight 18×11-inch wheels with exclusive, specifically designed Demon-branded 315/40R18 Nitto NT05R drag radial tires front and rear; add 3.5 inches to the Challenger SRT Demon’s overall width. The front side marker lights are styled to flow with the shape of the fender flares.
The entire chassis is e-coated for durability before final assembly.
Additional defining exterior features include the wide Air-Grabber hood scoop – the largest functional hood scoop (45.2 square inches) of any production car – and new Demon logos flanking each fender.
The driver is the focus in the interior of the Challenger SRT Demon, as it is for every model in the Challenger lineup.
Both the front passenger seat and rear seat, along with their corresponding seat belts, are deleted in the standard configuration of the Challenger SRT Demon.
Facing the driver is a flat-bottom SRT Performance steering wheel wrapped in Alcantara with paddle shifters. The SRT white-face gauges include a 200-mph speedometer and flank the 7-inch thin-film transistor (TFT) cluster display screen. A custom carbon fiber instrument panel badge with “Demon” script is located on the outboard vent and signifies the build sequence number.
A new four-point harness bar, available through Speedlogix, is available for use at the track. Mounting points for the bar are accessible, making it easy for customers to install without cutting or drilling anything.
Standard cloth seats include Ballistic II inserts with silver embroidered Demon head logo in the seat backs. An optional Laguna Leather Package includes leather covered seats and trim with embossed Demon head logo.
The 2018 Dodge Challenger SRT Demon will be available 14 exterior colors: B5 Blue, Billet Silver, Destroyer Grey, F8 Green, Go Mango, Granite Crystal, Indigo Blue, Maximum Steel, Octane Red, Pitch Black, Plum Crazy, TorRed, White Knuckle and Yellow Jacket.
Production of the 2018 Dodge Challenger SRT Demon begins later this year at the Brampton (Ont.) Assembly plant.
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