Dodge Challenger
Dodge Challenger
Dodge Challenger
Dodge Challenger
Dodge Challenger
Dodge Challenger
Dodge Challenger
Dodge Challenger
Dodge Challenger
Dodge Challenger
The whole 392 thing was a total coincidence. So says Dodge Challenger chief engineer Tom McCarthy. In 2009, McCarthy and his team were discussing a punch-out of the Challenger SRT8’s rather peaky 6.1-liter V-8 for more midrange torque.
“I always thought that engine was tuned to the horsepower number,” says McCarthy, meaning that to reach the 425-hp benchmark engineers tuned the engine for revs to the detriment of usable torque. McCarthy and his team settled on giving the big-block a 0.9-mm increase in bore to 103.9 and a 3.6-mm stretch to the stroke to 94.5, for a total of 6410 cc.
hese days, engineers work strictly in metric units, even at U.S. car companies. “I had no idea what the displacement worked out to in cubic inches,” claims McCarthy, until Dodge brand president and CEO Ralph Gilles casually asked in a meeting. Okay, math whizzes, it actually works out to 391.15 cubic inches, but that’s close enough for Chrysler to roll out the marketing war wagons. Way back in the late 1950s, hemi-head 392s powered the so-called forward-look Chryslers, including the fabulous 300 letter series, although it never was installed in a Dodge Challenger.
The 2011 Challenger SRT8 391.15, base price around $46,000 makes 470 hp at 6000 rpm and, perhaps more important, 470 lb-ft of torque, a gain of 50 lb-ft. The torque peak is lower, too, at 4200 rpm versus 4800 in the old 6.1. And, yes, the engine is still painted Hemi Orange.
It also moves the SRT8 to 60 mph in 4.5 seconds, 0.3 seconds quicker than the last SRT8 we tested, and through the quarter-mile in 12.9 seconds at 114 mph, almost a half-second quicker than the old mega-Challenger. (We only have test data on an automatic-equipped 6.1-liter SRT8, so the comparison isn’t totally apples-to-apples with this six-speed manual 392.)
Even quicker times might be possible outside of California, where the pumps only serve premium rated at 91 octane. McCarthy figures the car can improve by a tenth or two to 60. We shoved in a bottle of STP octane boost but have no way to determine how much effect it had until we can test the 392 back at our Ann Arbor headquarters.