The most powerful machine ever created by man, the Saturn V rocket, boasted a power-to-weight ratio of roughly .0067 pound per horsepower*. Only 17 were ever built at an inflation-adjusted cost of roughly $2.7 billion each. They harnessed liquid hydrogen, kerosene and magic to propel 29 large-stoned men into orbit — some all the way to the moon.
You couldn't go to your corner rocket ship store and buy one, however.
But you can go to your corner rocket ship store and buy a 2013 SRT Viper. Or a 2012 Chevy Corvette ZR1.
Both cars, although equipped with far more modest power-to-weight ratios of only 5.2 pounds per horsepower, can also be fueled right at your local Gas-and-Sip. They come with warranties, sticky tires and shift-it-yourself six-speed transmissions. And though they might not take you to the moon, low-earth orbit isn't out of the question should you get it wrong.
Mercifully, despite many trips into triple digits, two racetrack visits and hundreds of miles on the open road, we didn't get it wrong.
The Saturn V, SRT Viper and ZR1 Corvette have more in common than their impressive power-to-weight ratios. All three are fodder for freedom-loving gratuity hounds. All three are made to unleash hell when fully throttled. And all three will make you famous: the former for lifting its occupants into space on a trail of fire and hubris, the latter two, of course, because YouTube exists.
And in all three cases it might just be worth it.
Open the throttle on either of these cars and there's mountain-moving power and tectonic torque at your disposal. When the numbers are left to the Society of Automotive Engineers it's a near dead heat, with the Viper cranking out 640 horsepower and 600 pound-feet of torque to the Vette's 638 hp and 604 lb-ft. We don't leave it to the SAE, however.
We leave it to the dyno.
And on the dyno the ZR1's advantage in the explosive power delivery department is made immediately clear. Despite similar peak power and torque figures, the Corvette enjoys a 50-70 lb-ft advantage throughout much of the midrange. This torque hit manifests itself in a tire-frying Gong Show — even on the freeway. Though unbridled zeal with the throttle isn't recommended, it is mind-blowingly awesome.
But it's nowhere near as demanding as the Viper. Ever.
Big Power, Big Responsibility
So it was with carefully tempered enthusiasm that we arrived on a 50-degree overcast day at the 1.8-mile Streets of Willow Springs road course to settle the score. On a warm day these machines require patient respect until their tires are up to temperature. With the mercury so low and no sun to warm the track surface, they demand unthinkable restraint and a stubborn refusal to crash.
And it took only as long as our warm-up laps to be certain which car was both quicker and easier to drive.
The 2012 Chevrolet Corvette ZR1, with its arsenal of technology, was our ally. It is more predictable and more stable and simply easier to drive — particularly in the cold conditions. Its adaptive magnetic dampers yield both the body control and compliance necessary for commitment to every dynamic move.
Performance Traction Management, Chevy's advanced stability control, is there when you need it at corner exit. Too-eager throttle stomping will make its intervention burdensome, but it will still be blindingly quick. In the end, a perfectly calibrated right foot is better than PTM, but those are hard to come by. We liked the confidence PTM 5 provided and used it on our quickest lap.
The Viper's "Track" stability control setting is lenient enough to allow sideways moves certain to compromise lap times, but also a solid enough safety net that we used it for our quickest lap. We didn't, however, use the Viper's "Race" damper setting. Even the "Street" setting was too stiff for the track on this day. Without the compliance to absorb the track's small surface imperfections, the Viper's ride was busy at the limit, which diminished our confidence.
After all, we know few drivers partial to bouncing past the edge of grip. Most prefer a calculated, controlled breach of adhesion and that's not available in the Viper. But it is in the Vette.
As a result, the ZR1 was just over a second quicker:
2013 SRT Viper: 1:23.0
2012 Chevrolet Corvette ZR1: 1:21.9
Is This Necessary?
At the end of the day the Viper's creators are as unapologetic in their approach as the car is from behind the wheel. Erich Heuschele, manager of SRT Dynamics Engineering, told us that the Viper might behave this way on a slower track like Streets, but the car is designed for faster, smoother circuits. "We could have compromised the Viper for slow, rough tracks, but that's not what it is for. Our owners want an uncompromised track car."
It's a point with which we wouldn't argue if we thought the Viper would be quicker than the ZR1 on a bigger, smoother track, but we don't. And despite what Ralph Gilles, president and CEO of SRT brand might tell you on Twitter, there's far more to going quickly than simply mixing spring rates and cojones in the proper ratio. A good driver's car is one that's as sensitive to a driver's needs as it is physically capable.
That the Viper is uncompromisingly stiff is an inarguable point among the SRT heads of state. That it should be — or more philosophically — that it needs to be is less clear.
But That's the Point
But with only about 2,000 Vipers sold annually it's not a deal-breaker for SRT. The enthusiast community should be thankful to still have 2,000 dedicated lovers of the stiff ride among our ranks. And the Viper will serve them well in the right environment.
Because when it comes to knowing you're driving something legit, nothing sends the message more clearly than the Viper. It snorts and pops and spits and at the end of the quarter-mile, where it's swallowing tarmac 1.2 mph quicker than the ZR1, there's no question this car is something special. And something utterly badass.
Both cars, at 11.5 seconds, ran identical quarter-mile times in our testing — the Viper at 127.3 mph and the Vette at 126.1 mph. Sixty mph arrived in 3.6 seconds in the Vette and 3.7 in the Viper. Both produced 3.4-second 0-60 times using a 1-foot rollout as on a drag strip.
Perhaps the biggest point of contention here is that the Vette makes this acceleration easily accessible using its PTM-based launch control. In any PTM mode the Vette will limit power to the ground to match available grip. And it does it using the same graceful, high-resolution control it executes during corner exit.
The Viper, too, has launch control that's available in any stability control mode and easily accessed via a steering wheel button. And we used it. But the result, partly because of its high launch rpm and partly because of its ineffectiveness in limiting power to the ground, was a chest-pounding burnout. This, says Heuschele, is just how it works. We got the best launch the old-fashioned way: We earned it.
Handling tests were a wash. The Viper was marginally quicker through the slalom and the ZR1 produced higher lateral acceleration. But after our handling and braking tests it was clear that despite tires with similar treadwear ratings, the ZR1's Michelin Pilot Sport Cup tires make more grip. Given equal heat, the Viper's Pirelli P Zero Corsas are certainly sticky, but they're no match — in the dry anyway — for the Vette's barely streetable rubber.
Circling the skid pad at a record-tying 1.1g lateral acceleration in the ZR1 drove this point home with painful clarity as we attempted to hold ourself in its hilariously unsupportive seat. The Viper's 1.03g is no slouch, certainly. And its seats, though rock hard, were meant for this duty. It was several tenths quicker through the slalom, clocking 73.7 mph vs. the Corvette's 73.1 mph.
Perhaps most telling when it comes to grip is the Corvette's 95-foot stop from 60 mph. Certainly its carbon-ceramic brakes didn't hurt (the Viper's rotors are cast iron), but it's the tires that matter most in this single-stop test. And at 101 feet, the Viper's stop was undeniably longer.
Viper vs. Corvette ZR1: Inside the Control Rooms
When it comes to interior quality, though, there's no question which is better. The Viper controls this part of the contest to the same extent that Tito Ortiz would dominate Nancy Pelosi in an MMA cage match. It's hardly worth addressing again the abundant and utterly miserable ways the ZR1's interior lets down this otherwise remarkable machine.
By contrast, the Viper's interior is modern, beautiful, functional, dedicated to the cause of going fast, and it doesn't stink like fiberglass resin. Its shell-type seats, though hard, are infinitely better at holding their occupants in place than the marshmallow-padded chairs in the Vette. Instruments in the Viper are well placed, well prioritized and abundant.
Our test car, fitted with the optional GTS Interior package, had leather everywhere and an 8.4-inch UConnect touchscreen with an intuitive interface. When properly equipped, the car is even a WiFi hot spot. Imagine, mind-melting acceleration and the ability to Facebook about it.
Who could ask for more?
And in the End
Here's the thing: Despite the Viper's downsides relative to the ZR1, we can't help but love the silly thing. Yes, it seems gratuitously stiff, yes, it's brazen, and — good or bad — it announces itself wherever it goes. But it has grown up.
It's easier to drive than the previous-generation Viper and because of its better composure, power and weight improvements, it's undeniably faster. At $138,490 including the Track Pack and GTS Interior package, it should be.
And though we refuse to drink the braver-is-better Kool-Aid peddled by Gilles and team, there's value in an uncompromised supercar — the full extent of which might only be accessible to a tiny percentage of drivers a tiny percentage of the time. If you're OK with that then the Viper is for you.
But the $124,345 Corvette wins this test because it's better than the Viper in nearly every way: Faster, more comfortable and easier to drive, it makes the Viper's uncompromising ethos seem utterly unnecessary. And the fact that it's due for replacement in a few months only makes matters worse for the all-new 2013 SRT Viper.
See it however you want; we're just glad these rocket ships are still around.
*Yes, we know. It's not possible to precisely convert thrust to horsepower. We could have used gigawatts to express the energy released by the Saturn V, but then you'd have no idea what we were talking about. Even though you saw Back To The Future.
The manufacturers provided Edmunds these vehicles for the purposes of evaluation.