“You couldn’t do it,” Tim Kuniskis said bluntly. It was the night before the 2017 New York International Auto Show. Just minutes earlier, Dodge had officially unveiled the 2018 Challenger SRT Demon, the 840-horsepower super-Hellcat that can rip through the 1/4-mile in 9.65 seconds. I was sitting alongside Kuniskis, Head of Passenger Car Brands at Fiat Chrysler, in one of two Demons onstage as media and Dodge fans pored over its every angle.
I’d asked Kuniskis, previously the President and CEO of SRT, whether owners of “regular” Challenger SRT Hellcats could upgrade their middle-rung 707-horsepower muscle cars to Demon-level performance. The Dodge exec made it seem nearly impossible.
“Number one, the engine is completely different,” he told me. “We deck-hone the block, a different machining process on that. New crankshaft, new connecting rods, new pistons, new camshaft, new valvetrain, new supercharger. Basically, it’s just the heads that carry over.”
He continued. “The suspension, technically, I guess you could replicate, but you’d literally have to rebuild the whole car. You can’t duplicate the trans brake. You could duplicate the driveline—you’d have to replace the driveshaft, the half shafts, and the rear gear assembly. You could probably take the torque converter. That’s about it, really.”
Kuniskis’s answer shows his obvious pride in what SRT engineers have accomplished with the Demon. The car offers a whole raft of equipment and technology that’s never before been offered on a production car, all aimed at making it the quickest stock vehicle ever to run the quarter-mile. The suspension he mentioned? It’s a trick active system that goes all the way soft up front and firm in the rear to promote weight transfer on a drag strip launch—but snaps back to a firmer, more stable setting when you need to steer. The trans brake? It’s a tried-and-true piece of drag racing hardware, one that no automaker has ever before offered from the factory—in part because aftermarket systems have a reputation for grenading drivelines if used clumsily.
SRT engineers made hundreds of changes, big and small, to create the Demon. It’s more than 200 lbs lighter than the Challenger Hellcat it’s based on; it makes 133 more horses, 120 more lb-ft of torque, and shaves more than a second off that car’s 0-60 time—and still meets all emissions, fuel economy, and crash safety regulations. This is a nine-second car that pops wheelies, yet still carries Dodge’s 60,000-mile drivetrain warranty.
No, it’s not fair to compare aftermarket tuner offerings to the factory Demon. But it is inevitable. So I went to the guy building the quickest hot-rodded Hellcats in the world to see how he could replicate the Demon’s performance, and at what cost.
Joshua Schwartz is the owner of High Horse Performance, a Smyrna, Delaware-based speed shop specializing in the third-generation Hemi V8 engine. High Horse-tuned Hellcats routinely run nine-second quarter-mile times—clearly, Schwartz knows how to build a ‘Cat that runs with the Demon.
“To get a standard Hellcat up to Demon levels, it’s really just turning up the boost, doing exhaust work, intake work and tuning,” Schwartz told me over the phone. Add in a gearing swap, from the factory 2.62:1 final drive to a shorter 3.09, and you’re in the Demon’s neighborhood. “We have a ton of customers where we take them from 11 psi, the factory boost, to 15 psi, retune them with exhaust work, then gears, drag radials, and on their race gas tune typically they’ll run 9.80 with full-weight Hellcats.” Strip out the 200-plus pounds of weight that the Demon sheds, and you’re well on your way to 9.65, Schwartz says.
But you’ll need plenty of practice to do it. High Horse’s developments are all real-world tested on the shop’s white Challenger Hellcat. Nicknamed “TopCat,” it currently runs a 9.15-second quarter-mile on stock engine internals and the factory ZF eight-speed automatic transmission. “When the car was running 9.5s, 9.6s, it took me a month and a half, eight trips to the track, before I learned how to launch the car,” Schwartz told me. His best times are achieved by loading the torque converter at the line, releasing the brake, then patiently adding in throttle. “As I feel the rear end squat, I can just roll in quicker on the gas pedal, but I have to initiate that weight transfer myself,” Schwartz said.
Schwartz said his shop is experimenting with suspension upgrades to help with weight transfer, and his TopCat runs with a race seat, race fuel, the NHRA-mandated chute, and drag radials. The Demon’s combination of launch control, trans brake, and suspension-assisted weight transfer likely make a measurable difference in the car’s drag strip performance, Schwartz said.
So, what would it cost to build up a Demon-chasing Hellcat? High Horse offers a package with 18 psi of supercharger boost, a race gas tune, drag radials, swapped rear end gears, and exhaust upgrades. “It’s right around a $10,000 package,” Schwartz says, “and with drag radials we had a bunch of guys last year running in the 9.5 to 9.7 range consistently.” Such a setup usually nets around 800 rear-wheel horsepower, Schwartz says, though he prefers to go by drag strip times over chassis dyno numbers.
A base-model Challenger SRT Hellcat with an automatic transmission skates in at just under $69,000. Add ten grand for High Horse’s upgrades and tuning expertise, and you’re running mid-nines for right around 80 grand. With the Demon expected to come in at just under $100,000, the savings adds up to a whole bunch of spare rear tires. So why spring for the Demon at all?
“I think the fact that it has a warranty is huge,” Schwartz says. “That alone, to a lot of our customers, is really a huge selling point, because pretty much everything I do, I’m voiding the warranty on that car.” Add in the super-limited production numbers—3000 Demons slated for the US, 300 for Canada, one model year only—and the peace of mind of knowing your speed equipment is street legal and engineer tested, and suddenly that factory-built drag racer begins to make sense.
Not that Schwartz and the High Horse Performance team are worried. “We’re hoping that once the Demon comes out, we’ll get a nice influx of them through our shop for roll cages to make them NHRA legal,” he said. And perhaps some of those Demon owners will ask him to add a few horses on top of the 840 that Dodge offers. “I don’t know how aggressive they were, if they left horsepower on the table,” he said. “There might still be some room in there for tuners like myself to get our hands on the cars and turn it up a little bit more.”