"How is it possible that we've never dynoed a Hemi Charger?" The question hung in the air like an apostrophe as we pondered the burnt orange 2011 Dodge Charger R/T in our stable.
We've dynoed many flavors of Mopar including Challengers in R/T and SRT8 trims, a Viper, even a Ram. But never a Charger.
Have Charger, will dyno. Off to MD Automotive's Dynojet we went.
The 2011 Charger R/T carries a 5.7-liter V8 dishing up 370 bhp at 5,250 rpm and 395 lb-ft at 4,200 rpm. It's backed by five-speed autobox. With its iron block and pushrod-actuated two valves per cylinder, this mill might appear to be lifted directly out of the sixties. However, it sports a few modern twists.
The new Hemi's got the ability to shut down half of its cylinders by essentially 'collapsing' the hydraulic lifters that actuate four of its eight intake valves. This cylinder deactivation system saves fuel during certain part-throttle situations by increasing the engine load (e.g., opening the throttle) on the remaining four cylinders.
That's all well and good, but this is a dyno test. And that's where the Hemi's variable valve timing can be put to good effect. All of its valves are actuated by a single cam; the variable timing mechanism adjusts both intake and exhaust valve timing in lockstep (only the Viper had a concentric-cam arrangement to facilitate independent valve timing for the intake and exhaust valve timing in a pushrod engine).
The Hemi's VVT may be something of a compromise, but it still allows the torque to plumped up a bit by improving volumetric efficiency across the rev range. The result can be seen below:
The Charger generates a peak of 393 lb-ft at 4260 rpm, while turning out more than 350 lb-ft at any point north of 2800 rpm. Its power peak of 360 horsepower arrives right at the 5300 rpm rev limit. Note that this is lower than the 5800 rpm in Dodge's literature due to a 140-and-change mph speed limiter encountered while on the dyno.
It's nice, too, that the Charger's automatic transmission doesn't downshift of its own accord when in manual mode. Many autoboxes (the Ram's included) overrule your better judgement in this situation when pedal meets carpet.
That little hitch in the torque curve at 4700 rpm was present in every one of the eight or so runs on the dyno. It's more of a curiosity than anything, since it was so repeatable and did occur in a particularly detonation-sensitive part of the torque curve. You'd normally see this kind of stuff happen at peak torque where cylinder pressures are higher.
We came away from this test impressed -- the standard-issue workaday Hemi V8 is quite healthy, comfortably generating more power than what Chrysler claims. Imagine if it wasn't forced to lug around so much car.