Supercharged 6.2L Hellcat HEMI Detailed

[scottm]

Supercharged Hellcat V8 Engine Detailed
http://www.autoevolution.com/news/super ... 81815.html

Almost a week ago, Dodge unveiled the first photos and specs of this year's most anticipated muscle car - the awe-inspiring 2015 Dodge Challenger SRT Hellcat. As we're sure you know, the centrepiece of the package is the monstrous blown 6.2-liter HEMI V8 producing over 600 horsepower.

Even though Dodge released further info on the powerplant, the brand still keeps its lips tightly shut about the exact horsepower and torque figures. Boo and hiss, but nevertheless, other technical aspects of the mill are certain to make jaws drop.

The American carmaker's most potent mass produced engine ever shares just 9 percent of its bits and bobs with the less powerful 6.4-liter HEMI V8. The latter provides the 2015 Dodge Challenger SRT with 485 horsepower and 475 lb-ft (644 Nm) of torque.

So what has been changed over the 6.4-liter V8? Well, for a start there's a twin-screw supercharger dominating the engine bay. Sealed forever with a special type of premium full-synthetic lubricant, the 2.4-liter blower can rotate at a maximum 14,600 revolutions per minute and has a 2.36:1 drive ratio.

Featuring integral charge coolers and an electronic bypass valve which regulates boost pressure to a respectable 11.6 psi, the supercharger draws fresh air via intakes integrated in the inner headlamps. The final stage of the four-stroke combustion cycle is dealt by a 2.75-inch exhaust system with dual exit tips. Combining comfort with sportiness, an electronically controlled butterfly valve system keeps noise levels down at low rpm and unleashes the full staccato burble at higher revs.

Moving on to the belly of the beast, highly durable forged-alloy pistons are connected to powder-forged connecting rods. High load capacity bushings and carbon-coated piston pins are also on the menu, while both cylinder heads are heat-treated for extra toughness. The hollow-stem cylinder exhaust valves are sodium-cooled and benefit from steel-alloy heads which can withstand scorching hot temperatures up to 800 C (1,472 F).

Naturally, the blown 6.2-liter HEMI V8 powering the 2015 Dodge Challenger SRT Hellcat needs a pretty special fuel system to keep the powerplant well fed with high octane gasoline. Just to name a few of its highlights, the high performance fuel system is comprised of eight high-flow injectors, a variable pressure in-tank pump and 0.5-inch fuel lines. If you're a bit of a leadfoot, be warned: all the fuel accommodated in the 18.5-gallon (70-liter) tank will run out in a mere 13 minutes if you give the throttle pedal the Full Nelson.

As expected from a muscle car of this caliber, there are only two very well sorted transmissions available: a track-proven Tremec TR6060 six-speed manual derived from the SRT Viper sporting an upgraded clutch and an exterior cooling system, as well as the all-new TorqueFlite eight-speed paddle-shift automatic. Even thought the front and rear axles are chunkier than on the normal SRT, weight is kept under control thanks to the heavy use of special lightweight alloys.

The 230 mm rear axle sports an asymmetric electronically controlled limited-slip differential which aids the driving dynamics of the vehicle with good levels of traction and grip, sports car roadholding and smooth power delivery when accelerating hard out of corners. Of course, the hardware is also able to offer plenty of hoonage whenever the mood takes you for a little sideways, tire shredding action.

Standard 245/45 Goodyear tires or optional Pirelli P Zero rubber can be shoehorned on 20-inch forged-aluminum wheels measuring 9.5 inches across. The "Slingshot" rims feature a split-seven spoke design and are painted in a ominous matte black hue. The Brass Monkey (dark bronze) finish is an optional extra. Last but not least, braking power is sourced by a Brembo system with six-piston calipers up front and 15.4-inches discs on all four corners.

Don't know about you guys, but the 2015 Dodge Challenger SRT Hellcat is shaping up to be one helluva machine. If you want one right now, tough luck - the first ones will arrive in U.S. dealer showrooms towards the end of 2014.

Simply amazing!

[scottm]

This article has some of the same info, but a few more details, too. Worth reading through as well.

More Details Offered On New Hellcat Hemi Engine
http://www.enginelabs.com/news/more-det ... mi-engine/

We have additional information on new supercharged 6.2-liter Dodge “Hellcat” Hemi that will power the upcoming Challenger SRT and Charger SRT. While horsepower numbers still haven’t been released — Dodge is promising 600-plus and industry observers continue suggesting 650-plus — there are more details on the engine’s components and specs.

The Hellcat will be the Chrysler Group’s most powerful V8 engine and built with 91 percent new content when compared to the standard 392 Hemi. The foundation is an orange powdercoated cast-iron block with redesigned coolant passages. It’s fitted with a forged-steel crankshaft that Dodge says can withstand cylinder pressures up to 110 bar, or 1,595 psi. Crank vibrations are controlled with a specially tuned damper capable of 13,000 rpm. Forged aluminum pistons, powder-forged connecting rods and DLC pins make up the remainder of the rotating assembly.

The supercharger is key to the engine’s performance and puts Dodge on a more level playing field with the blown competition from the ZL1 Camaro and GT500 Mustang. The twin-screw rotors are specially coated to accept tighter tolerances and higher temperatures as well as resisting corrosion. Rated at 2,380cc per rev, the supercharger will be overdriven 2.36:1 for a max speed of 14,600 rpm. Fresh air is fed to the blower through an inlet port mounted where the driver’s-side marker light was located, and then routed into an 8-liter air box. The Hellcat relies on an integrated electronic bypass valve to regulate boost at 11.6 psi max and a huge 92mm throttle body to control power.

Fuel delivery was improved to satisfy the engine’s elevated thirst, including half-inch fuel lines and 600cc/min fuel injectors. Cooling the boosted air charge before it mixes with the fuel are two air-to-water intercoolers mounted in the supercharger housing. Dodge says the system is designed to keep intake charges cooled down to 140 degreesF.

“So effective is this feature that engine power will not be de-rated due to cooling demands, even after 20 laps of a grueling 3.1-mile road course at an ambient temperature of 100 degrees Fahrenheit (37 degrees Celsius).” claims Dodge.

Lubrication was also improved with a high-flow gerotor pump, oil-to-air heat exchanger and piston cooling jets. The heat-treated alloy cylinder heads hold sodium-cooled steel exhaust valves that can withstand 1,472F temperatures. Dodge says the valve lift will be .561 and .551 respectively for the intake and exhaust valves. And speaking of exhaust, the Challenger SRT will utilize a electronically controlled relief valve to accentuate the exhaust note booming through the dual 2.75-inch pipes. (see video below)

Finally, Dodge says its engineers ran the engine over 2 million customer-equivalent hours on the dyno as well as 24-hour endurance tests on the track. Another test included 125 consecutive drag-race starts.

Dodge promises more information is forthcoming, so stay tuned.