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Stock tuned Demon makes 874rwhp

by Patrick Rall on

The folks at A2Speed have dyno tested a 2018 Dodge Challenger SRT Demon in stock form with pump gas, tuned with pump gas and tuned with Q16 racing fuel, and all of the numbers are impressive – with the tuned Mopar monster with race fuel making 874 rear wheel horsepower.

2018 Dodge Demon Tuning

Dyno Testing the Demon

The A2Speed video begins with a baseline dyno run with the Demon running the stock “pump gas PCM”, which delivers an advertised figure of 808 horsepower. With that setting, the supercharged Challenger sent 730 horsepower to the rear wheels in 100% factory-stock form.

Next, using software from Syked ECU Tuning, the A2Speed team added a custom tune to the stock PCM to work with 93 octane pump gas, so literally nothing changed shy of the tune. With just that tune, the Demon made 819.8 rear wheel horsepower in the video below and in other tests, that number climbed to 840 rear wheel horsepower. In short, the video shows the Demon picking up 90 rear wheel horsepower from just a 93-octane tune while later picking up another 20 horsepower for a total of 110 rear wheel horsepower being gained from just a pump gas tune.

Finally, not shown in the video, the A2Speed team filled the fuel tank with Q16 race fuel and added an ECU tune to work with this high octane racing fuel. Again, this was using the Syked software with the stock PCM and on this run, the supercharged, drag-ready Dodge made 874 rear wheel horsepower at the wheels. That is an increase of 154 horsepower over stock with just a tune and race fuel.

Engine Horsepower Conversions

For those wondering how these numbers convert to engine horsepower, here is some quick math.

The stock run was in the 808 horsepower setting and the 2018 Dodge Challenger SRT Demon made 730 at the wheels. This represents a loss of 78 horsepower or about 9.7% drivetrain loss.

When we apply that 9.7% drivetrain loss ratio to the tuned 93-octane RWHP figure of 840 horsepower, the tuned-and-otherwise-stock Demon is making around 930 horsepower at the crankshaft.

Applying that same ratio to the tuned Q16 number leads us to an engine power figure of 968 horsepower from the tuned 2018 Challenger Demon running oxygenated race fuel.

Now, we should point out that dyno numbers can be affected by all sorts of variables, so this same Dodge Demon with the same engine tunes might make more or less horsepower on another dyno in another shop. However, the gains should be relatively steady from one dyno to another, so focus less on the final numbers and more on the fact that with Q16 race fuel and an engine tune, an otherwise stock Challenger Demon picked up more than 150 horsepower at the wheels.

Check out the video below for a look at the A2Speed dyno runs with the Demon in stock form and with the 93-octane tune.

Patrick Rall was raised a Mopar boy, spending years racing a Dodge Mirada while working his way through college. After spending a few years post-college in the tax accounting field, Patrick made the jump to the world of journalism and his work has been published in magazines and websites around the world.

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