Until now, what you know about 2015 Challenger SRT Hellcat is that its big numbers – 707 hp and 650 lb-ft of torque can produce some small numbers:
Dodge says it will do the quarter-mile in 11.2 seconds at 125 mph with the stock Pirellis.
The time is dropping to 10.8 at 126, on drag radials.
And after we had driven it, we invested some time in testing of the small numbers of our own.
So below are 10 facts you should know about the fastest, most powerful stock muscle car ever produced.
1. Few engines are as appropriately named.
At full throttle, the Hellcat sounds so pissed-off that you might think you will find another behind you, one above, or one on either side too.
Well, we can say that this imaginary formation can make perfect sense, as the name is military-derived:
Hellcat fighter aircraft and tank destroyers (which were constructed by Buick) fought on our side in WWII.
Dodge’s history of militarized engine monikers like the Apache, Viper, Tigershark is very strong….
…but this one, and the noise the engine creates, wins.
A 2.75-inch exhaust system uses front and back resonators, with electronically controlled valves that can bypass the ones out back.
The range of flow can be dictated by the drive modes:
When the Challenger is in track mode, it’s gloriously loud…
…but in the default setup at a highway cruise it avoids annoying drone.
Here we speak of a high-tech approach compared to the block-off plates on a Boss 302 Mustang, or even the vacuum-operated valves in Corvettes and Camaros, providing more control and customization.
But I’m pretty sure people will find the fuse and pull it.
I will the next time I’m in one.
2. A lot had to change to make the first factory-supercharged Hemi.
By part value, the 2015 Challenger SRT Hellcat engine is 91 percent new when compared with the 6.4-liter Apache V8 on which it is based.
Also, here we have some new stuff:
High-heat heads, rocker covers, high-heat exhaust valves, connecting rods, pistons, crankshaft, block, oil pump, oil pan.
And of course, the supercharger.
Most of the carryover was measurements (valve locations, bore, bore centers), fasteners, and hang-on parts like the alternator.
3. It’s the fifth-most-powerful production car today.
Which are the models ahead of the Hellcat?
Note that three of the top five are Fiat-Chryslers.
Sergio likes some power.
Chrysler had to upgrade its dyno cells just to test the engine.
4. Heat is the enemy of efficiently making an ungodly hellstorm of power.
Not many new ideas went into making 222 more horsepower than the naturally aspirated 6.4-liter.
One of the concerns was to keep everything cool enough to reach those numbers.
That implies a cooling for the transmission, separate low-temp cooling loop for the intercoolers (a setup originally cooked up for use in high-efficiency small-displacement applications), and a big oil cooler.
To feed it, they popped a hole in the left parking lamp to ram-air the airbox.
Also, development target for the car was to endure a 20-minute track session in 100-plus-degree heat without having to start pulling power from the engine.
As a proof, one of our fans claimed that Dodge really did well with the cooling…
…and from whole WannaGoFast race, his Hellcat was the only car that didn’t lose power.
5. The Hellcat needs a bigger automatic transmission…
…as in physically larger.
All 2015 Challengers are eight-speeds, while the one in the Hellcat uses stronger, wider gear, which makes the transmission case longer.
Also, at full throttle it shifts quickly with a little kick to let you know it is after speed and not smoothness in track mode.
Hellcat has borrowed the standard Tremec six-speed manual from the Viper, but adds an external oil cooler.
So, the Hellcat is capable to shift as smoothly and as quickly as you desire.
6. The engine was just part of the upgrade, albeit a big part.
The Hellcat comes with an about 210 pounds extra weights than the SRT 392 but, it really doesn’t feel like it.
Much larger sway bars are here to deal with the added weight and to fix some of the previous model’s boat, like tendencies.
Instead of seeming like it’s going to tip, the body stays flat enough to stimulate some confidence, letting the 9.5-inch-wide Pirellis out back do their job.
And also to ensure that the thing actually stops, the front brakes have been upgraded from four-piston to six-piston calipers, clamping onto discs with lightweight aluminum hats.
A testament to the brake system:
I was much more concerned with bad things happening when I went for the right pedal than when I went to scrub the speed it wrought.
7. Patience is a virtue, street or strip.
Yes, you can steer the Challenger Hellcat with your right foot.
This should not surprise you much.
The thing that came as a little bit of a shock was how with ease this can be achieved.
So don’t be overconfident (more on that below).
Comfortably long throttle travel makes it a progressive walk from idling in traffic to roasting the black 20-inch marshmallows.
The chassis is surprisingly neutral…
Which gives you leeway…
Which you might need…
…because-650 freaking lb-ft of torque.
But do not think it is difficult to get roasting.
A pre-drag burnout is a side-step away.
Even with a minimal brake-torquing (we revved to 1500 rpm before dropping the hammer on a Hellcat auto) it will put an angle between the car and the wall very quickly.
Recovery from such a stylish leave from the line is again aided by that long right pedal.
Then you just line up again and tell everyone you weren’t going for a time.
8. Doesn’t look that different, doesn’t really need to.
The 2015 Challenger SRT Hellcat makes an instant recognition.
The changes that were made for the 2015 model evolve the styling from ’70-aping to ’71-inspired.
And it all works, even if the car looks like a 6:5 scale model of the original.
But unlike the big-power Mustangs, and Camaros the muscliest Challenger doesn’t have a ton of styling differentiation compared to a base V6 car.
Here we have subtle changes:
SRT in the grille, a lowered grille brow, an aluminum hood with heat extractors flanking a scoop, a deeper splitter, and a taller spoiler.
Aside from the “SUPERCHARGED” badges, there is almost no ornamentation to suggest nutso power.
The thinking seems to be:
Once it starts moving, you will know.
9. Two keys, because you shouldn’t trust yourself.
Red fob provides accessibility to every last one of the 707 hp.
Black fob limits output to 500 hp, or a little higher than a stock SRT 392.
Call it rain mode.
Since few can be trusted with absolute power, valet mode limits the engine to 4000 rpm, keeps ESC on all the time, and, on automatic models, alters shift points and starts out in second.
10. You can’t put a Hellcat engine in a Viper. You shouldn’t want to.
For people wondering to know what Chrysler’s most-powerful-ever engine is doing in anything but the Viper:
Two different animals.
The SRT people are describing the Viper as a track car you can drive on the street…
…and the Hellcat as a street car that can go to the track.
The Hellcat engine and attendant cooling weigh about 180 pounds more than the Viper V10, so you can stop right there.
However, in case you have not put down your shoehorn yet, know that the Hellcat V8 is way too tall to fit under the Viper’s carbon-fiber hood.
So just don’t.
And in any case, the sensible thing to do is buy a Dodge Challenger Hellcat and enjoy the engine in a place it belongs.
Because it only costs $60,990 for the manual model, which is crazy cheap for America’s most insane engine.