---
title: "Watch The Dodge Challenger SRT Demon’s 840-HP V8 Engine Scream On the Dyno"
description: "It had to be factory-tested on a setup originally designed for NASCAR engines."
date: "2017-06-07"
modified: "2017-06-07"
authors:
  - name: "Kyle Cheromcha"
    job_title: "Editor-in-Chief"
    link: "https://www.thedrive.com/authors/kyle-cheromcha"
url: "https://www.thedrive.com/watch-this/11223/watch-the-dodge-challenger-srt-demons-840-hp-v8-engine-scream-on-the-dyno"
categories:
  - "Dodge News"
  - "News"
  - "News by Brand"
  - "Watch This"
tags:
  - "Challenger"
  - "Challenger SRT Demon"
  - "Coupe"
  - "dodge"
  - "dyno"
  - "FCA"
  - "sports car"
  - "V8"
---

# Watch The Dodge Challenger SRT Demon’s 840-HP V8 Engine Scream On the Dyno

![](<https://www.thedrive.com/wp-content/uploads/images-by-url-td/content/2017/06/engine.png>)
*\<em\>www.thedrive.com</em>*

The candles have been lit, the incantation is nearly complete, and the Dodge Challenger SRT Demon is about to be summoned by dealers nationwide. But before that happens, take a moment to appreciate the extreme testing done on the 840-horsepower supercharged V8 engine in order to sharpen the knife of a car that, in the words of *The Drive* editor Mike Guy, "hates humans."

To wring out every last bit of power from the Hellcat's existing 6.2-liter engine, the tiny crack team of FCA SRT engineers [worked in near-total secrecy](<https://www.thedrive.com/new-cars/11088/dodge-challenger-demon-will-still-run-a-sub-10-second-quarter-mile-on-street-gas>) to redesign over 60 percent of the internals, including the cast-iron block, high-strength alloy pistons, powder-forged connecting rods, and crankshaft. They also rigged up the car's special air intake chiller system and rigged the whole thing to run on 100-octane gas. Parts suppliers were given the bare minimum details to work with, sometimes just a target figure, and internal simulator work helped piece everything together.

Of course, testing a screaming V8 engine that's being covertly developed poses its own set of challenges. The SRT crew was able to do most of the work in their own building down the road from FCA's main campus in Michigan, but they still needed to use the larger facility's engine dyno setups to dial everything in. In order to keep the banshee's howl from giving everything away, tests were originally conducted on nights and weekends.

https://youtube.com/embed/LzLPXoXqh_c

Later, a more clever solution emerged—altering the [dyno](<https://www.thedrive.com/watch-this/10022/watch-this-6-second-nissan-gt-r-max-out-a-dyno-with-2700-horsepower>) display screen to always read 707 horsepower, so anyone walking by would think they were just testing a plain-Jane Hellcat engine. There was more than one problem, though. Despite using a setup at FCA's headquarters that was originally designed for NASCAR engines, they were still limited by the building's fuel delivery system, which almost couldn't keep up with the engine's insane 1.36-gallons-per-minute appetite at full blast.

The video above shows one of these tests, and pay attention to the numbers at bottom left (and the red-hot exhaust pipes). Those 840 horses get all the attention, but it's the Dodge Demon's sky-high torque figures that get it off the line for that vaunted nine-second quarter-mile run. At a relatively tame 4500 RPM, the engine is already putting out almost 660 horsepower and 770 lb.-ft. of torque. That's already more than the peak figures for the [Chevrolet Camaro ZL1 1LE,](<https://www.thedrive.com/news/10353/chevy-camaro-zl1-1le-extreme-track-performance-package-dominates-race-tracks>) and it's just getting started.

## Author
Overseeing an expert staff of writers and editors from his lair in Los Angeles, Kyle shapes The Drive’s singular approach to covering the automotive industry and car culture. He’s been with the site as a writer since 2017, taking over as editor in 2019. On a daily basis, Kyle is responsible for directing The Drive's editorial news and car review content strategies, setting special coverage priorities, managing complex reporting projects, and ensuring what you read on the page meets our high internal standards for quality and trustworthiness. He is also the executive producer of The Drive's YouTube channel, which was relaunched in February 2024 to great acclaim and has accumulated over 14M new views in its first year back on the scene. He hosts a biweekly series on the channel where he breaks down fascinating and complicated stories from the automotive world.

### Author social links  
[Bluesky](<https://bsky.app/profile/kylecheromcha.bsky.social>)  
[Instagram](<https://www.instagram.com/kylecheromcha>)  
[LinkedIn](<https://www.linkedin.com/in/kyle-cheromcha-1550248a/>)