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Serious drag tools: Demon anti-lag

by David Zatz on

Today’s 2018 Dodge Challenger SRT Demon news might be the most surprising so far: the Demon will be the first production road car to come with a “torque reserve” system – or what racers commonly call an anti-lag system.

Demon license plate

This system will also allow the Demon to leave the starting line with higher boost, reaching peak power more quickly as it heads down the track.

So what is the torque reserve system in the 2018 Demon? Dodge explained that “it lets more air flow through the engine before launch, allowing for increased supercharger rpm without torque overwhelming the brakes and spinning the rear tires.”

A normal supercharged engine has a period of time from when you first hammer the throttle to when you reach full boost – and full power. This period is called boost lag.

The torque reserve system – or anti-lag system, if you prefer – works by closing the bypass valve of the supercharger, which allows the boost pressure to raise. At the same time, the engine computer briefly deactivates alternating cylinders to allow RPMs to rise while keeping power output low.

On launch, when the system disengages, the Demon will leave the line at a higher engine RPM and a higher boost level, so it takes less time for the Hemi engine to reach its peak performance levels. It is also a little easier on the drivetrain components when preparing to launch, over a similar car at the same rpm.

Another result of an anti-lag system like the one in the 2018 Dodge Challenger SRT Hellcat is a unique exhaust tone, as the alternating cylinder deactivation creates a sort of stutter. To showcase this unique exhaust sound, which has never been replicated by any factory-built road car, Dodge has offered up a new ringtone for your cell phone on

Finally, this week’s teaser information comes with more mystery math in the form of another license plate. The 2018 Challenger Demon has a custom Michigan plate which reads 3.9+221=405. There is no information to go with that odd math, but this should lead to a new round of speculation as to what the numbers might mean.

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