Power corrupts, and absolute power corrupts absolutely.

The challenge facing SRT Viper chief engineer Graham Henckel and his team was to keep the car as raw as the hard-core Viper fans would want, yet make it legal (all cars must now have Electronic Stability Control, as much as some Vipernatics feel it’s an affront to their masculinity) and expand the car’s market by making its extreme performance more accessible.

After spending some time on both road and track in the 2013 Viper, my guess is they’ve succeeded.

One way to achieve the desired duality was to create two different models.

The SRT, with a black cloth interior, single-mode Bilstein dampers, and dual-mode (on/off) ESC, is closer to the intent of the original Viper.

The GTS, with full leather, two-mode Bilsteins (Track and Street), four-mode ESC (On, Sport, Track and Off), and fancier trim, is intended to attract customers looking for a domestic alternative to Ferrari, Lamborghini or Porsche.

A departure from previous Vipers is that the 2013 model debuts only as a coupe. Henckel got all PR-trained when asked the obvious question: when is the roadster coming?

Throwing his hands up in mock horror, he said, “Roadster? Did we say anything about a roadster?”

He did allow that the coupe’s roof is essentially non-structural, hence could be removed without having the car bend in two. In other words, there be a roadster; he just wouldn’t say how soon. I’m guessing not much more than a year.

The new Viper is unmistakably a Viper, although just about every part has been changed. The massive hood, close-coupled passenger cabin and chopped-off rear end continue.

The front-hinged hood, double-bubble roof and hatch lid are carbon fibre parts (made in North America), while the doors and rocker panels are superformed aluminum.

These high-tech materials help bring the weight of the car down by about 40 kg. The lightest version is actually under 1,500 kg, despite Viper’s lingering image as a big, heavy car.

The side exhaust system remains, but the pipes are enclosed, so while it still gets a bit warm down there, clumsy egress from the car is less likely to send you to the nearest Burn Unit.

Stiffness is increased by about 50 per cent, thanks in considerable part to a huge X-brace over the engine, connecting the suspension towers to the firewall.

Despite the big heavy image of former Vipers, they were not particularly well-suited to big, heavy owners — the cabin was distinctly cramped. The seats in the new one sit about 40 mm lower, the seat track travel is increased by 90 mm, and seat height is now adjustable by 15 mm.

The all-aluminum 8.4 litre engine is a pushrod design, and does not have a dry sump like many high-performance engines. But the swinging oil pickup performs one of the principal functions of a dry-sump — preventing oil starvation in fast cornering — and has proven itself in countless endurance races.

A new plastic intake plenum improves airflow and shaves about 3 kg off the top of the engine, where it does the most good for lowering the centre of gravity.

Output rises to 640 horsepower (from 600 in the 2010 Viper), while peak torque is now 600 lb.-ft. (versus 560).

A six-speed Tremec manual transmission is what you’ll be getting, because it’s the only one on offer. Revised internal ratios reduce the rev gaps between ratios and, combined with a shorter final drive ratio in the limited slip differential, give the car much snappier, more responsive performance, on the drag strip, on the track or on the road.

It also means Viper hits its top speed of 330 km/h in sixth, instead of fifth as before. Zero to 100 km/h comes up in the mid-three-second range.

Massive brakes with calipers from Italian racing brake maker Brembo bring things to a halt right smartly.

A new front suspension was designed to be faster, says Eric Heuschele, manager of vehicle development and the car’s suspension guru. More-responsive steering, plus wider front track and tires give the front end what Heuschele calls “more authority,” for better turn-in.

The Napa and Sonoma valleys offer plenty of twisty two-lane roads to have a wee bit of fun with a car like this.

Our street time, starting in an SVT model, proved that the new Viper is remarkably more civilized than the old one. It is still fast, still firm-riding and still loud, although not everyone is a big fan of the coarse, flat-sounding V10 exhaust note.

You could almost see this as a daily driver, if your daily drive wasn’t too long.

The pedals are offset to the left, to clear the massive central tunnel needed to house the engine, which is set well back in the chassis. It takes some getting used to.

Neither I nor my driving partner noticed the adjustable pedals at first. With just a tilt but non-telescoping steering wheel, it was difficult to get a proper driving position. Once we messed with the pedals, it was better.

Visibility isn’t great. The windshield header is low; you aren’t quite peering out from inside a mailbox, but that image did come to mind.

The re-configurable Thin Film Transistor instrument cluster includes an analogue tach graphic. As you approach the red line, the Viper’s snake-head logo (dubbed Stryker by Viper Nation) starts glowing red to let you know it’s time to upshift. Very cool.

Shifting is a lot easier than before, as the revised shift linkage is both shorter and wider — less chance of catching fifth when you wanted third on the way up; or second when you wanted fourth on the way down. The clutch is heavy, but not impossibly so.

On the street, you can break the speed limit and never get out of first gear. So we welcomed the chance to try the car at Sonoma Raceway.

This highly-technical track with lots of elevation changes wouldn’t test the car’s top speed, but would indicate if the Viper has become more than just a straight-line weapon.

I began in a base SVT, then moved up to an SVT with Track Pack — Pirelli Corsa race-oriented tires on lightweight wheels, and brakes with high-thermal-resistance, two-piece rotors — and finished with a GTS, also equipped with Track Pack.

The improved front-end bite is noticeable, even at fairly modest cornering speeds. Indeed, it initially feels just a trifle twitchy until you realize this is how it’s going to be.

Even on the warm-up lap, I could feel the difference the Track Pack makes — and it’s all in those tires. Response is notably crisper, and the improvement got more noticeable as I got more heat into them.

The main advantage of the GTS was the four-mode ESC, but with so few laps, I really didn’t get a chance to play much with it.

So the new Viper is everything the old one was — fast, loud, scary — and a whole lot more comfortable. It’s better-riding, better-handling and much safer.

Will it cause sleepless nights at Ferrari, McLaren or Porsche?

No. Viper may not be quite the sledge hammer it was, but to mix a metaphor, it’s still a broadsword compared to the rapiers produced by the higher-end European sports car makers.

Besides, Viper costs a third as much as a Ferrari or McLaren.

The Jaguar XKR-S might be closer to Viper’s swim lane, but it comes only with an automatic, and is a giant leap or two up the comfort/luxury axis.

Even the Nissan GT-R, nearer to Viper in price, has sophisticated four-wheel drive and a dual-clutch transmission, neither of which Viper offers.

Ford’s new Shelby GT500 might be in this tent, with even more power, albeit a semi-genuine back seat — and a bargain price, too.

I think Viper’s main competition remains the higher-end Chevrolet Corvettes: Z06 and ZR1. It handily beats them on most objective performance criteria, but a new Corvette isn’t far down the road, so it’ll once again be a tight race.

And tight races are always the most fun to watch.