Marc N. goes under the skin of the
born again SRT Viper and tries a pre-production prototype on track at Gingerman
raceway
“I told the team to make a 640-horsepower
Miata (Mazda MX-5).” Ralph Gilles president and CEO for SRT Brand and
Motorsports, as well as senior vice president of product design for Chrysler
answered us with that unique line when we asked him what the goal was with the
new Viper. Chrysler’s halo sports car has never been even remotely lithe like
the Japanese roadster. In fact, we’re quite sure no one has ever put the
V10-powered Viper and the MX-5 in the same sentence before those words came out
of Mr. Gilles’ mouth.
The original Viper concept arrived in 1989
as a simple, powerful, and extroverted halo car for Chrysler. It has never
featured an overly friendly chassis beneath the wild exterior design. The basic
details of the car haven’t changed dramatically as this fifth-generation Viper
comes to market in early 2013. It’s still left-hand drive only, with a giant
V10 that sends its power – now 631bhp from 8.4-liters to gigantic rear tires
solely through a manual gearbox.
In
fact, we’re quite sure no one has ever put the V10-powered Viper and the MX-5
in the same sentence before those words came out of Mr. Gilles’ mouth.
The space frame continues on with a boxed
steel structure, albeit heavily revised. SRT engineers told us that Viper
owners track-drive their cars and drive them hard. Exotic technology makes
repair far too expensive after the occasional shunt. A new magnesium bulkhead
and aluminum engine x-brace contribute to a 50% stiffer structure. Carbon fiber
for the hood, roof, and deck lid, combined with aluminum door skins, help drop
the Viper’s curb weight by 45kg compared with the last version.
Bolted to this revised structure is a
suspension system with aluminum A arms front and rear. The setup is similar to
the fourth-generation car, so much so that German-sourced KW threaded coil-over
dampers from the old track-focused Viper ACR bolt right up to the new car. Not
that you necessarily need that modification given the improvements in this area
of the Viper. SRT worked with Bilstein for the two damper options. The base
Viper features non-adjustable aluminum-body shocks. The top-spec GTS model uses
gas-charged monotube DampTronic Select dampers with 46mm pistons. These units
feature two specific modes via a button on the center console. The road setting
is softer than the base car’s tuning and the track setting is firmer. The GTS
combines this with 10% stiffer springs. The 27mm sway bars on the Viper are
hollow and the rear suspension has been settled for improved rear-toe
compliance.
Bolted
to this revised structure is a suspension system with aluminum A arms front and
rear.
The steering system continues to be a fully
hydraulic setup. It utilizes a 16.7:1 ratio, with 2.4 turns lock-to-lock. The
increased structural rigidity of the space frame and the retuned steering
combine to give excellent feel and accuracy, something lacking in
previous-generation Vipers.
Strong brakes are always important on a
631bhp sports car that can break 200mph. Viper engineers worked with Brembo as
well as StopTech in California. The four-piston 44 and 40mm – Brembo calipers
are forged aluminum. All Vipers feature 355 x 32mm rotors front and rear, but
the optional SRT Track Pack adds StopTech two-piece slotted rotors that offer
increased performance and lighter weight. Our time in a pair of near
production-ready development Vipers at Gingerman Raceway in South Haven,
Michigan, USA, revealed an overall impressive braking system, but pedal feel
and performance did degrade a touch with heavy use even with the SRT Track Pack
rotors.
It’s
a non-run flat design, with 275/35ZR-18 installed up front and a mammoth
355/30ZR-19 in the back.
Putting all this power to the ground and
allowing the newly refined chassis to work to its full potential meant that
engineers had to revisit the wheel and tire package. The newest Viper utilizes
Pirelli tires for the first time. The fourth-generation Viper had bespoke
Michelin tires either Pilot Sport PS2 or Pilot Sport Cup. The new standard tire
is the Pirelli P Zero. It’s a non-run flat design, with 275/35ZR-18 installed
up front and a mammoth 355/30ZR-19 in the back. The SRT Track Pack adds
ultra-lightweight track wheels fitted with the circuit-oriented P Zero Corsa
tire. Both tires performed flawlessly during extended lapping sessions at
Gingerman, but the Corsa tire added a welcome degree of steering precision and
front-end grip. Power is managed through a GKN ViscoLok speed-sensing
limited-slip differential and it does an excellent job, giving the Viper
impressive traction.
Dodge
SRT Viper interior
Possibly the biggest advancement in the new
Viper is the fitment of stability control for the first time. Viper engineers
could have gone down the easy route and added a simple system, just to keep the
regulatory bodies happy. Instead, they developed a system that allows owners to
have fun with their cars, even with it fully turned on.
The base car’s stability control system
features two modes fully on or fully off. A simple button on the steering
enables the driver to quickly toggle between the two. The GTS adds two
additional settings, a sport mode with a higher threshold before intervention,
and a track mode that disables the yaw control but keeps wheel spin in check.
We found all three of the ‘on’ settings to be excellent and even the most
stringent default mode was very unobtrusive. It’s a very impressive system,
especially considering it’s a first for Viper.
