When it comes to American power, there have been quite a few cars to transcend the good old V8-powered, straight-line drag racing muscle. You probably already know that we’re talking about the original Ford GT40 and the Chevy Corvette. But, the car that pushed the boundaries of American performance the most is the Dodge Viper ACR.
By adding two more cylinders to the eight-banger formula, the Viper offered a new dimension of an American performance car. By distilling the venom further the Viper ACR became the best testament to the statement that there’s more to American power than just quarter-mile sprinting.
The ACR nameplate found its way on several Vipers throughout its history, and we’ll put a spotlight on the 2016 ACR Viper, the last and arguably the boldest of its kind.
Background
On a shoestring budget but rocket fueled by a big idea, Chrysler exec Bob Lutz and chief designer Tom Gale presented the Viper as a concept car at the 1989 North American International Auto Show.
Following back-and-forth with then-CEO Lee Iacocca, the Team Viper was formed in March 1989, consisting of 85 dedicated people handpicked by chief engineer Roy Sjoberg. Some extra Italian spice came from newly acquired Lamborghini which developed the V10 on the foundations of Chrysler’s LA series V8.
The original Viper was dreamed up as a modern-day Shelby Cobra, a perfect rebound from the malaise era and Lee Iaccoca’s botched attempt at making the brand exciting by creating the underwhelming Chrysler TC.
The humble budget in question was $70 million; a huge sum indeed, but a modest budget by Detroit standards and also five times less than the TC’s development costs.
The production Viper was paraded by Carroll Shelby at the 1991 Indianapolis 500 in a fitting introduction to the no-nonsense sports car.
The Viper went on sale as a 1992 model, infamously missing even basic features like exterior door handles and air conditioning. All that didn’t matter though because the Viper had exactly what Chrysler lacked for decades: a sensual design, 400 horses of largely unassisted American power, and a sub-zero cool name. Unquestionably, the Viper was an instant icon.
The early nineties were indeed the last era of raw power before safety concerns took over and technology spoiled the fun. Over the years, the Viper evolved from an intimidating bare-bones performance car standing up to its name into a controlled dose of venom, albeit still in ample packaging. With each new generation, Dodge had been adding safety features and aids in efforts to make the Viper more amicable for daily use.
On the other hand, the ACR was for those who still felt that driving a Viper should feel closer to diving into a snakepit rather than tapping on the glass to wake a sleepy serpent up at a local zoo.
The first mention of the ACR came during the second-gen Viper, officially named SR II and produced from 1996 to 2002. The package was available only for the GTS coupe, while ACR abbreviation stood for American Club Racer, designating a car built for enthusiasts ready to take the Viper to the tracks.
Initially, the package deleted the radio and the air conditioning unit, but added adjustable Koni shocks, racy air intake resulting in a power bump to 460 horses, special BBS wheels, and race-appointed interior. The ACR Viper was still a far cry from the full-on Viper GTS-R race car, but it brought a taste of racing glory to owners of this track day special.
After skipping the third generation, the ACR returned for fourth-gen ZB II Viper, in not one, but two guises: ACR and ACR-X, the former being the roadworthy V10 weekend toy, while the latter was a track-only warrior on wheels.
Development of the Dodge Viper ACR
The VX I, or the fifth generation of Viper had been in the making since 2011 and the debut at the 2012 New York Auto Show saw the car presented under the SRT brand. For the first time ever, the Viper was presented exclusively as a hardtop coupé and it was further tamed compared to the predecessors with systems such as electronic stability control, traction control ABS. For the first time in its history, the fifth-generation Viper even got cruise control.
On the other hand, the Viper was still a V10-powered beast with 640 horsepower coming from the 8.4-liter ten-banger and 3,354 lb in its base variant. SRT also offered the option of an SRT Track Package which lightened the car further to 3,297 lb, also adding grippier Pirelli P Zero Corsa rubber and ensuring better stopping power thanks to two-piece brake rotors.
Still, everyone knew that the SRT department was just warming up. Chrysler’s wild child was fully expected to present an ACR variant of the signature sports car. That happened exactly two years later at the 2014 SEMA auto show in Las Vegas, the perfect place for such a bombastic premiere.
After a four-year hiatus, the new Dodge Viper ACR saw the light of day as a white coupe with offset black and red striping, a massive downforce-generating rear wing, and ultra-lightweight 19-inch alloys. SRT gave the ACR Viper concept a special diet, shedding weight whenever possible, thus making a fantastic foundation for a production version.
A year later, in 2015, SRT introduced the production variant. The 2016 ACR Viper had an MSRP of $121,395 and a long list of extras making it an even more capable track car.
With numerous upgrades and an equal amount of reductions, the final Dodge Viper ACR was created as a perfect antithesis to its civilian counterpart. This is a story about what made it special.
Chassis
The skeleton of the VX I Viper was an updated steel spaceframe made by Metalsa, a Monterrey, Nuevo León, Mexico-based company with operations in the United States and a longtime supplier of the Chrysler Corporation.
The chassis was re-engineered to achieve better structural rigidity combined with lower weight and a 50:50 distribution for perfect balance. Some solutions like the structural X-brace in the engine compartment were taken directly from the racing program, while aluminum was used for braces and impact beam, making the fifth-gen Viper safer, lighter and more precise. The dashboard construction was constructed in magnesium, keeping the weight even more down.
Working in conjunction with Plasan, Chrysler Advanced Engineering Team made efforts in further weight savings. The Dodge ACR Viper replaced the aluminum X-brace with a carbon fiber one, improving the structural stiffness of the most stressed part of the chassis while simultaneously keeping the overall weight lower than the standard car.
The revised chassis was just one step towards making the ACR the ultimate American track weapon by means of maximizing the handling capabilities of the Viper.
Body
Apart from shedding weight, the main goal of the 2016 ACR Viper was to improve cornering performance. That being said, the Chrysler Advanced Engineering Team focused on lightening the body panels and increasing the downforce.
Doing a very good job at both fields was a carbon fiber aerodynamic body kit The front splitter, the rear diffuser, and the huge carbon fiber wing generate massive downforce, 1,500 lb to be precise, thus increasing overall stability and road holding over the regular Viper.
The increase in downforce comes at a penalty since increased drag lowered the top speed to 191.5 MPH. However, on the tracks, what matters more is having grip in slow sections and being able to take advantage of the downforce and the brakes to push the car to its limits and shed some seconds.
Carried over from the record-breaking sportscar is the optional Extreme Aero Package, a true highlight of the 2016 ACR Viper. The $6,900 aerodynamic package was designed to increase the downforce even more, to a total number of 2000lb, or almost a metric ton, making the Viper ACR the production car generating the highest downforce output.
To achieve this impressive feat, SRT re-engineered the body kit, equipping the Dodge ACR Viper with a detachable front splitter extension, four dive planes on the front corners of the car, and the extended rear diffuser featuring six removable strake extensions, thus increasing straight line stability. On top of that, removable hood louvers over the front tires were designed to reduce air pressure around the front wheels while simultaneously providing extra downforce.
The most prominent change was an adjustable Extreme Aero rear wing. Compared to the Dodge ACR Viper’s wing, the optional one is bigger, is positioned further rearwards, it stands taller, measures wider than the car itself and features gurney lip and specially designed end plates to minimize drag while producing optimal downforce.
The Extreme Aero Package reduced the ACR Viper’s top speed to 177 MPH, but significantly improved road holding and on-track capabilities, becoming a desirable extra for most buyers.
Engine and Transmission
The SRT division didn’t focus on improving the power output, so the mid-front mounted V10 was kept as is. With that in mind, the 8.4-liter engine retained 645 horsepower at 6,200 RPM and 600 lb-ft of torque at 5,000 RPM.
As numerous other American performance cars, the Viper was available with Tremec TR-6060 6-speed manual transmission, a racy heavy-duty unit engineered to handle big horsepower output. The TR-6060 was first used in the Viper in 2008 on the ZB II generation and it had been ever since.
Suspension and Steering
To use up the maximum from various track layouts, the Dodge Viper ACR has highly adjustable Bilstein coilover shocks designed specifically for it.
First of all, the suspension is more than two times stiffer than the setup used in the Viper TA (Time Attack), a sporty variant standing between the baseline Viper and the all-out ACR. Moreover, the ACR has more negative camber than the standard Viper,
The aluminum-bodied shocks provide independent 10-way rebound and compression adjustability while also enabling more than 3 inches of ride height adjustment, granting that the ACR Viper can be optimized to perform differently on the road and at the tracks.
Furthermore, the Electronic Stability Control system works in five modes, each catering to specific conditions, driver’s experience, and expectations from the ultimate Viper. That being said, the modes are Full-On, Sport, Track, Rain, Full-Off.
Brakes, Wheels and Tires
Experienced track day drivers know that brakes and tires often mean more than sheer power, and to that end, the 2016 Dodge Viper ACR gained improvements in these vital departments as well.
First, there are the beefed up ABS-assisted Brembo Carbon Ceramic Matrix brakes measuring 15.4 inches in the front and 14.2 inches in the back.
The carbon-ceramic treatment replaced the previous steel brakes, thus offering better brake fade resistance, improved heat dispersion and more efficient stopping power when the six-piston front and four-piston rear calipers grab the massive rotors.
The aforementioned detachable air ducts also provide additional cooling to the brakes, enabling the ACR Viper to run on its full capacities for an extended period of time.
The Dodge Viper ACR sits on new lightweight 19-inch wheels wearing Kumho Ecsta V720 ACR rubber specially designed for the car, measuring 295/25R19Z in the front and 355/30R19Z at the rear. These tires are virtually slicks with a few superficial grooves to make them qualify as street-legal.
Interior
The interior of the ACR Viper isn’t as Spartan as one would expect, but it’s evident that the SRT division did a lot to keep the Viper track focused.
The ACR still has touchscreen infotainment, air conditioning, and multi-speaker audio, but even these features were altered to stick to the main purpose of the car.
In order to keep the weight down, the speaker system was reduced to three units while the aircon automatically stops cooling the cabin if the car is driven hard to maximize the performance of the engine.
The seats were altered to manually adjustable buckets five-point harnesses for the driver and the co-driver. Then, there’s the reduction of noise cancellation and carpeting, followed by ample use of carbon fiber and Alcantara. In a proper track car manner, the Alcantara-wrapped steering wheel had a color-coded strip on the 12 o’clock position. Funnily enough, the ACR Viper retained cup holders for those rare off-track drives.
Dodge Viper ACR on the ‘Ring
Unparallelled aerodynamic grip enabled the Viper to lap the Nürburgring Nordschleife in 7:01.67 in an unofficial run with SRT test driver Dominik Farnbacher behind the wheel in October 2015.
The near-record Nurburgring run was followed by an unprecedented effort from Viper enthusiasts worldwide. In 2017, a dedicated Viper racer Russ Oasis launched a crowdfunding campaign, gathering both big and small sponsors to reunite Farnbacher and the Viper on the Nürburgring in an attempt to officially claim the record.
Dominik was joined by his younger brother, Mario Farnbacher, and fellow races Lance David Arnold and Luca Stolz who joined forces to try to claim second place for street legal cars at the famous Green Hell. By 2017, there was a new record holder, the Lamborghini Huracán Performante with 6:52.01, a time impossible to top.
Before finally crashing their ACR Viper, Dominik Farnbacher lapped the track in 7:03.45, Mario was close at 7:03.23 while Lance David Arnold did it in 7:01.30, breaking the ACR’s unofficial record.
Despite not conquering the Nürburgring officially, the Viper ACR set thirteen record laps on numerous American raceways including Willow Springs Raceway, Virginia International Raceway, Road Atlanta, and Laguna Seca. Eleven out of thirteen records were set by SRT vehicle dynamics and development engineer Chris Winkler.
Legacy
By today’s sports car standards, the Dodge Viper ACR was a dinosaur of a car even when it came out in 2016. It followed a straightforward philosophy of a huge naturally aspirated engine, three pedals, and no fancy electronics to keep it in order.
Sadly, the interest for such cars has rapidly decreased in recent years and Dodge felt that when the fifth-gen Viper proved to be the worst-selling one. That resulted in pulling the plug in October 2015, while disassembling the Conner Assembly Plant on August 31 2017 made everyone clear that the Viper will be no more.
With that in mind, the ACR is definitely the last great Viper and the collector car market responded accordingly. Low mileage examples of the Viper’s energetic twin brother with an adrenaline addiction can be found for over $200,000 if equipped with the Extreme Aero Package, but it’s honestly a shame these examples probably won’t ever be driven like they are supposed to.
The Viper had to die, but at least it went down with a heroic blast as one of the greatest American cars of the 21st century.
