How Dodge Squeezed 1,025 HP From The Challenger SRT Demon 170's Supercharged V8

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The camshaft is the only significant part Dodge didn't change in developing the craziest muscle car ever.

The Dodge Challenger SRT Demon 170 is the street-legal muscle car king to end all muscle cars, generating 1,025 horsepower and 945 lb-ft of torque from a 6.2-liter supercharged V8 running on E85 fuel. With sticky Mickey Thompson street-legal drag radials as standard and on a prepped surface, the Demon 170 can hit 60 mph in 1.66 seconds and demolish the quarter mile in 8.91 seconds at 151.17 mph. But best of all, it's 100% street legal and ships straight from the showroom floor, with a manufacturer warranty.

But how does the Last Call that was delayed because it kept blowing up engines make all its power?

Dodge
Dodge
Dodge

1. Fueled By E85 Ethanol

To generate such high horsepower, the Demon 170 needs to run on E85 - an 85% ethanol blend. It can run on 91 octane pump fuel, but it only generates 900 hp and 810 lb-ft in this trim. Only.

Juiced up on the good stuff, though, 1,025 hp is available. But what happens if you're running half a tank of 91 and top the rest up with E85? The Demon 170's D170 V8 engine (the Hellephant crate engine is designated C170) has ethanol sensors that can calculate how much ethanol is in your fuel mixture on the fly, automatically limiting horsepower to prevent early detonation and damage to the powertrain. High-flow fuel injectors pump fuel at 164 gallons per hour to keep the D170 fed, while colder heat range spark plugs help ignite the ethanol more efficiently.

Theoretically, the Demon 170 is the world's first eco-friendly, sustainable muscle car. That's a relative term, however, as Dodge's CEO, Tim Kuniskis, says it will produce 45% less CO2 than regular gas. "It won't save polar bears, but it will go fast," says Kuniskis.

Dodge
Dodge

2. Uprated 3.0-Liter Supercharger

Dodge says the new engine is not a production version of the Hellephant, but it does share a number of similarities. The supercharger, for instance, is a modified version of the crate motor's item. The 3.0-liter supercharger generates 40% more boost pressure at 21.2 psi and has 30% more airflow thanks to a 105mm throttle body. Over and above this, it has a 3.02-inch pulley and a 2.68 drive ratio, with 14% more overdrive compared to the Hellcat Redeye Widebody.

Accompanying the supercharger is the SRT Power Chiller - which reduces induction temperatures by 45 degrees Fahrenheit - and the Air-Grabber hood and Air Catcher headlamps to ensure enough airflow. The result is 1,582 cubic feet of air per minute reaching the Demon 170's engine.

Dodge
Dodge
Dodge

3. Coping With Immense Cylinder Pressure

With more boost pressure, more air, and more fuel driving up outputs to insane levels, pressures within the combustion chambers have reached new heights: 2,500 psi when running on E85. That figure is 32% higher than the 797-hp Hellcat Redeye Widebody. In order to contain that much explosive force, Dodge engineers had to use aerospace-spec steel studs with steel inserts in the aluminum cylinder head, increasing the clamping load by 38%. The main bearing caps had to be strengthened, too, using the same aerospace-grade steel bolts and billet steel main caps to increase the clamping load by 44% compared to the Redeye. The block had to be machined in a specific way to accommodate these new items.

Dodge
Dodge

4. New Bearings and High-Strength Con-Rods

With all the extra heat, force, and everything else going on, Dodge used a new copper-lead construction for the main and rod bearings, increasing the load capability of the engine and reducing the chances of spun bearings and oil starvation.

The connecting rods also received an overhaul to increase their strength. Even the pin bushing support was strengthened to help the rods cope with the drastic increase in pressure within the combustion chamber.

Dodge
Dodge

5. Valves To Cope With Any Fuel

Using high-concentration ethanol places additional strains on a motor, including the ability to prematurely wear the valvetrain. The solution was to use nitride-coated intake valves with strengthened valve guides and seat materials to prevent premature wear.

Dodge
Dodge

6. Damping Crank Vibrations

With so much force being generated when burning E85 fuel, Dodge had to develop a new viscous damper for the crankshaft. This damper reduces torsional vibration to prevent the engine from shaking itself to pieces.

Dodge
Dodge

7. Updated Transmission & Stronger Driveline

To accommodate all that power and torque, the TorqueFlite 8HP90 eight-speed automatic transmission received an updated outputs flange, which was needed for the new prop shaft, which has an increased tube diameter, thicker tube walls, and larger CV joints resulting in 1 30% increase in strength compared to the original Dodge Demon. Aerospace-grade metals were used to reinforce the 240mm rear axle housing by as much as 53%, while the inboard and outboard CV joints pair with 43-spline rear half shafts to remove as much slack as possible from the driveline under duress.

Dodge
Dodge

Everything Else

There's so much more to the Dodge Challenger SRT Demon 170 than just an engine and a gearbox, from the 315/50R17 Mickey Thompson drag radials on aluminum and carbon fiber wheels to the TransBrake 2.0 system, drag race-specific suspension modes and staggered widebody design. You can even spec a parachute mounting system direct from Dodge, and owners have to sign an indemnity acknowledging that, while street legal, the Demon 170 can't be driven in everyday conditions like rain and cold weather without a high likelihood of disaster. The Demon 170 is the first-ever eight-second factory muscle car, and is possibly the best way to send the combustion-powered muscle car out with an almighty bang.

Dodge
Dodge
Dodge
Dodge

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