Adding Lightness for Quicker E.T.s – A Look at Demon’s Unique Front Disc Brakes

“You don’t need 200-mph brakes on a 160-mph car.” Those are the words FCA Demon development engineer Jim Wilder used to explain why the 2018 Dodge SRT® Demon employs smaller front disc brakes than its SRT Charger and Challenger Hellcat siblings. “It all comes down to the fact Demon’s P315/40R18 Nitto drag radials carry a manufacturer speed rating of W, which equals a maximum of 168 mph.” To ensure proper performance, the Demon is electronically limited to stay below 168 mph.  


By contrast, the Hellcat Challenger and Charger twins are designed for maximum speeds of 199 and 204 mph (respectively) and wear (Y)-rated (186 mph and above) tires to help make it happen. As a consequence, Hellcats are equipped with huge 15.4-inch diameter front brake rotors (bigger than Viper!) and big six-piston Brembo® calipers to ensure stopping power that’s well matched to their top speed capabilities and race track brake fade requirements. Don’t think for a second though that these smaller brakes will negatively impact braking performance. With the super sticky Nitto tires the Demon actually stops from 60mph in 97ft! That is a shorter distance than any SRT vehicle, ever.  


In the case of Demon, let’s remember that it’s essentially a Hellcat that’s been optimized for quarter-mile drag strip action. Able to crank 0-60 in 2.3 seconds and cover the quarter mile in the mid-nines at 140 mph (on a prepared surface), that’s hauling serious butt. Since Demons don’t come close to the 200-mph barrier, exhaustive testing by Wilder and his team showed they can get by with smaller 14.2-inch diameter front rotors and four-piston Brembo calipers. They’re similar to the front disc brake package used on 6.4-liter Scat Pack Challengers but with aluminum calipers in place of the Scat Pack’s iron items.  


Remembering that Wilder’s team took a fine-tooth comb to the Hellcat package in search of weight saving opportunities, Demon’s smaller front brakes aren’t the result of some random minimalist quest. Rather, the smaller binders shed nearly 20 pounds of unsprung and rotating mass from the nose of the car. These smaller, lighter parts consume less energy to set into motion when the drag strip light flashes green. That was the ultimate goal.  


Out back, the Demon shares its 13.8-inch diameter brake rotors with Hellcats and Scat Packs. Perched directly atop the rear tire contact patch, where the rubber meets the road — or slicks meet the strip, as the case may be — weight saved here is of dubious value. And so the Hellcat rear disc brake rotor size wasn’t reduced. Jim Wilder comments, “With the narrow front tires used in all-out drag strip mode, the rear tires play a greater role in staging the car. We wanted to have plenty of holding power on the starting line. Better still, the Hellcat/Scat Pack 13.8-inch rotors and four-piston calipers fit inside the smaller (18-inch diameter) Demon Hole Shot rims just fine. Again, we didn’t change the Demon’s rear brake diameter, our focus was on the front brakes.”  

Fans of the 1967 Dodge WO23 HEMI® Coronet, one of Demon’s spiritual ancestors, will recall how a similar strategy played out half a century ago. Built specifically for sanctioned drag racing, Dodge substituted the Street HEMI V8’s regular 11×3-inch front brake drums with lighter, smaller 10×2-inch units. But at the rear of the car, the hefty 11×2-1/2-inch Street HEMI V8 rear brake drums remained to help squash the slicks into the starting line. Only 55 WO23 HEMI Coronets were built (plus an equal number of Plymouth RO23 HEMI Belvederes). They were the first Dodge vehicles to employ this staggered-size brake drum diameter trick (the 1962-’65 Max Wedges and Race HEMIs used 10-inch drums at both ends).  

And that’s the story of how and why the Demon came to have smaller — but lighter — front disc brakes than the Hellcat. Simply stated, they’re the right parts for the job and further proof of how “adding lightness” throughout the car delivers amazing results and helps make the Dodge 2018 SRT Demon the world’s fastest accelerating production car*! Stay tuned to Demon Confidential for even more behind-the-scenes news about the Demon.

*Excludes non-mass production vehicles and hybrids, based on 0-60 times.


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