Thirteen minutes. That’s the amount of time it takes the 707hp Hellcat Hemi to completely drain the 2015 Dodge Challenger SRT’s 18.5-gallon tank at full throttle. We’ll pause for a moment as you try to wrap your mind around that. If you poured 18 gallons of fuel on the ground and lit it with a match, it would take twice as long to burn. It should then come as no surprise that the Hellcat’s ceramic catalytic converters and dual 2.75-inch exhaust are tested to withstand over 1,900 degrees.
Let’s contemplate the Hellcat’s power for a minute. In this day of rising power figures, the public has become a bit numb to their meaning. Right around the time America was fighting for independence from mother England, James Watt was busy quantifying how much work a horse could do in order to rate his new steam engine. Watt found out the average workhorse could continuously lift a 550-pound load by one foot every second. Now multiply that by over 700.
Stuffing your right foot into a motor north of 700 hp isn’t something most people do every day, so getting an invite to do so ranks right up there with getting a golden ticket to Willy Wonka’s chocolate factory. We’ve driven race cars with that kind of power before, so we were curious about how Dodge’s powertrain and chassis engineers would balance the sheer terror of 700 hp with the need for acceptable street manners. What they came up was nothing short of astonishing.
Our first face-to-face encounter with SRT’s stunning Hellcat was in downtown Portland, Oregon. We fired the 6.2L supercharged Hemi with the stab of a button, slotted the shifter of the eight-speed TorqueFlite automatic into “D,” and pulled out into city traffic. The Dodge PR people were wise to start us off in the bumper-to-bumper grind?it showed us right away how docile this beast can be. In fact, we didn’t see the first pound of the Hellcat’s possible 11.6 psi of boost until a full 10 minutes into our drive.
At idle, the Hellcat hums unobtrusively, the exhaust producing a playful crackle only once the throttle is blipped. In traffic, the SRT Challenger easily plays the part of dutiful commuter, and there’s a reasonable amount of travel in the throttle pedal that will allow you to live normally without unleashing the hounds of hell?or the cats, as the case may be. It’s in this mode that the judicious owner will have a fighting chance of pulling down something close to the expected 20 mpg on the highway. (Yes, Hellcat does come with a gas-guzzler tax?$1,700 for the automatic and $2,100 for the six-speed.)
Our first highway merge was a magic moment. Pushing down on the loud pedal launches you violently as the eight-speed TorqueFlight downshifts and the exhaust’s electronic valves bypass the mufflers. A black hole immediately opens up in front of the Hellcat and sucks you into it, leaving only sound and fury in its wake. That’s when you notice the seats are not only supportive and comfortable, they’re strong enough to keep from breaking loose from the g-force when the throttle opens up.
The Hellcat’s 92mm drive-by-wire throttle body is the largest one Dodge has ever used, and at full throttle, it gulps enough air to drain all the oxygen from an average bedroom in 60 seconds. This air enters an IHI-sourced air-to-liquid intercooled supercharger, which employs proprietary polyimide resin-coated rotors that spin at 14,600 rpm (max). Now compressed, the air is deposited in vast amounts with commensurate amounts of fuel via high-flowing Hemi heads into a deep-skirted, cross-bolted iron block. Translation: Hellcat is really good at making torque way down low and everywhere else. At just 1,000 rpm, the Hellcat already makes 413 lb-ft of twist?more than the base 5.7L Hemi makes anywhere in its torque curve.
Enigmatically, Hellcat is an engine that makes enough torque to live in harmony with a one-speed transmission, yet it’s mated to a world-class eight-speed automatic that manages to improve significantly on the 845RE eight-speed that debuted in the Durango, Ram 1500, and Cherokee. In ordinary Hemi Challengers and in 392 Hemi cars, the ZF-sourced eight-speed 845RE is called the 8HP70 TorqueFlite. When beefed up with additional pinion gears in the First and Third gear assemblies and given five extra clutch packs, the 8HP70 transforms into the Hellcat’s nuclear-proof 8HP90. If you prefer to shift your own gears, the Tremec-sourced TR-6060 six-speed uses a beefy 258mm twin-disc clutch, which can easily handle the torque. Let’s be clear here: Either way you choose to shift gears, Dodge has the Hellcat’s 650 lb-ft of torque covered!
Our two-hour drive through the Columbia River valley gave us little time to familiarize ourselves with the Hellcat’s many electronic enhancements?most of them part of, or adjunct to, the massive 8.4-inch Uconnect screen. The features of the Uconnect system could easily fill this entire magazine, but to the extent we had time to fiddle with them, we came away somewhat confused. This is a system that takes plenty of study and practice, and doing so will yield big results; the Uconnect with its Performance Pages is clearly the key to getting the most out of the Hellcat, right down to its adjustable settings for active launch control, shift light rpm, steering firmness, suspension response, and electronic traction control. Moreover, you can record drag strip passes, in effect turning any stretch of tarmac long enough into a track. You can monitor any gauge you want (ex. g-force, horsepower output, air/fuel ratio, 0-60 mph) on the central 7-inch instrument cluster screen, and even pull up a lap timer for track events.
On the scenic drive, we were torn between playing with electronics, and fighting to keep the locomotive-like power from pushing us off the cliff into the rocky river. We finally gave up on the gadget distraction and concentrated on the drive, and we were glad we did. The Hellcat is remarkable in that it hides its weight well, thanks to lots of tuning, a five-link IRS, and help from an electronically managed suspension.
The Hellcat has three performance modes; Street, Sport, and Track. (Technically, it has four modes if you include “Default,” a mode that allows users to select their own settings for suspension firmness, shift rpm, steering firmness, and level of traction control intervention). Let’s go over these and explain the difference.
In Street mode, Hellcat has a ride quality like a luxury sport coupe, totally befitting its price and its ability to move four adults in comfort. You won’t be embarrassed to give your mom a ride to church, and you won’t suffer from fatigue on long trips because the ride in Street mode is compliant, supple, and quiet. Better yet, Street mode still commands all 707 horses as long as you have the red key fob.
Switch over to Sport mode, and things get a little more serious. Shift points move up and get firmer, steering feel is stiffer, and the ADS Bilstein shocks are valved with more compression and rebound damping. There’s also less intrusion by the traction control system when the tires begin to argue with the pavement. Sport is a great mode for an active street driving style, such as the kind we were doing in the tight mountain switchbacks.
Track mode is just as it says. You get WOT shifts at redline made with lightning fast speed and with max firmness. Those gears hang in there too, such that if you breathe off the gas for a moment to correct your line, it won’t upshift and spoil your lap. That’s great on the road course as we found when we flogged the Hellcat at Portland International Raceway. Cool shift fact number two: in Track mode, the eight-speed TorqueFlite rev-matches gears when downshifting?the Achilles’ heel of automatics on road courses. With automatic rev-matching, the rear has far less tendency to step out on you while trail braking, making driver confidence higher, and lap times lower.
In “Track,” the electronically boosted steering goes to its lowest assist level. This does a reasonably good job of transmitting the road feel, but it’s still a little artificial feeling as there’s never a good sense of the slip angle for the outside front tire, which on Hellcat lives a tortured existence. Shock valving also gets more aggressive in “Track,” which is really important in a heavy car that sees lots of weight transfer from front to rear and side to side. A stiff shock means better braking, faster turn-in, and getting on the gas sooner for lower lap times. Here, the heavy Hellcat feels a full thousand pounds lighter than advertised when pushed at the limit, and that’s important to guys who expect to go up against lighter Mustangs and Corvettes.
None of this fun happens without good brakes, and the 15.4-inch, six-piston Brembo binders let this big cat know it’s on a short leash. In the rear, 13.8-inch vented rotors are complemented by fixed four-piston clamps, and together with the fronts are more than a match for the estimated 199-mph top speed of the Hellcat. Our only desire here is for Dodge to imbue the Hellcat with a wider footprint; at a 275 cross-section width, the Pirelli PZero rubber is significantly outmatched by the mass of the nose-heavy SRT and its 650 lb-ft of torque.
Speaking of which, detractors of the Challenger love to point out its weight as a disadvantage, and arguably so, since the Challenger does carry far more than its fair share of mass for a ponycar. Yet for many buyers shopping the ponycar segment, the Challenger’s large, comfortable muscle car interior make it the only one worth considering. That being the case, if Dodge engineers can effectively disguise the weight, they will have essentially trumped all comers.
On the dragstrip, the news is mixed. A polished and edited YouTube video with a Motley Cr?e backing track was released by Dodge PR and shows the Hellcat running 10.85 at 126.1 mph on DOT-legal drag radials in what we’re expected to believe is a drive-right-in-and-run-it deal. (Subsequent graphics say 11.2/125 on production tires.) On the dragstrip at Portland International (which is just 16 feet above mean sea level) we got just one chance to make a run, and posted a 12.50 at 117 mph.
The difference between our e.t. and their e.t. can be explained by the lack of traction, but the disparity between the published and observed trap speed?the best indicator of horsepower?can only partially be explained away. The dragstrip slide rule at Vexer.com says we should run 124.9 mph with 707 hp and 4,655 pounds (car plus driver). Working backward from the 117-mph trap speed and calculating observed horsepower, we get 588?not quite the 707 promised. Of course, the fine print in the Dodge press material says they made 150 drag passes during testing, so maybe we’ll hold off making judgments with just one pass under our belt.
One thing we’d like to point out about the paddle-shifted TorqueFlite: It is simply amazing. Whether drag racing or road racing, the shifts come immediately, they happen quickly (in 160 milliseconds or less), and when it hits, the exhaust issues a staccato note under full throttle that is music to the ears. The left-hand downshift/right-hand upshift arrangement is far superior to GM’s finger-pull downshift/thumb-push upshift, and when used in conjunction with the user-adjustable shift light on the Performance Pages, the Hellcat’s paddle shifters are a blast to play with.
So how does the Hellcat’s value stack up to the competition? Five years ago, the $59,995 price tag of the Challenger Hellcat might’ve been perceived as a bargain, but with competitors like the Ford Shelby GT500 (662 hp, $55,110) and the ZL1 Camaro (580 hp, $55,355), it’s a bit on the high side, even for 707 hp. When it comes to bragging rights on the street, the calculus is a little more complicated than dividing engine power by the total price; curb weight enters the picture because it has such a profound influence on performance, and not just in a straight line.
The math: Each horsepower of the Hellcat Hemi has about 6.35 pounds to move. When compared to the Shelby’s 5.87 pounds per horsepower, The SRT Challenger Hellcat is still going to see the Pony’s taillights, even after spending four grand more. Hellcat is, however, well ahead of the Camaro ZL1, which is burdened with 7.10 pounds for every rated horsepower. Nevertheless, the situation is complicated. The GT500’s bragging rights are temporarily suspended because production on the next version won’t start again until well after the Hellcat hits the showroom this fall. This is, of course, a non-issue for hard-core Mopar guys; the GT500 and ZL1 are dead players to the converted. We’re just providing the info for the impending bench race that is sure to ensue.
So you’re sold on the Hellcat and want one. The only problem is that there will only be about 1,200 built. With more than twice that many Dodge stores, product will be allocated only to the best dealers. And while there is technically a choice of options and a variety of colors (11 exterior and 4 interior choices), the reality is that you’ll have to take what’s there. Don’t look for any bargains and don’t get your hopes high for a testdrive, unless you want to elicit laughter from the salesman; just run to your Dodge dealer and hand over the cash now. You’ll thank us later. If you pre-order, you’ll actually have a say in how yours is built, and with luck you might be able to get the price down to MSRP. So what are you waiting for?
- Type: 370ci V-8, cast iron with revised cooling and piston oil squirters
- Block: Gen III Hemi, 4.09 (bore) x 3.58 (stroke)
- Oiling: wet sump, 7.5-quart capacity, 0w40 synthetic required
- Rotating assembly: induction-hardened forged steel crankshaft and rods; 9.5:1 compression forged pistons, powder-forged connecting rods
- Cylinder heads: pressure-cast aluminum, semi-hemispherical chambers with 2.13-inch intake valves and 1.65-inch sodium-filled exhaust valves
- Camshaft: hydraulic roller, .561-inch intake lift, .551-inch exhaust lift
- Induction: IHI-sourced, liquid-intercooled, twin-screw supercharger with integral overrun clutch, 11.6 psi of max boost, 600cc/min fuel injectors
- Ignition: dual coil-over-plug, electronically controlled
- Exhaust: dual 2.75-inch exhaust with twin electronic exhaust valves
- Fuel requirement: 91-octane minimum
- Output: 707 hp at 6,000 rpm, 650 lb-ft at 4,000 rpm
- Transmission: TorqueFlite 8HP90 eight-speed automatic or six-speed Tremec TR-6060
- Rear axle ratio: 2.62:1 (automatic) or 3.70:1 (manual)
- Front suspension: independent SLA with coil springs and ADS Bilstein shocks, 34mm solid sway bar
- Rear suspension: five-link independent with coil springs, 22mm solid sway bar, ADS Bilstein shocks
- Front brakes: 15.4 x 1.34-inch vented rotors with floating six-piston mono-block calipers
- Rear brakes: 13.8 x 1.10-inch vented rotors with fixed four-piston calipers
- Curb weight: 4,439 pounds (manual trans), 4,449 (automatic)
- Weight bias (F/R): 57/43
- Wheels amp; Tires
- Wheels: 20×9.5 “Slingshot” split seven-spoke alloy (matte black or “brass monkey”)
- Tires: 275/40R20 Pirelli PZero
Text Source: Hot Rod Network
Author: Johnny Hunkins