2013 SRT Viper GTS Suspension Walkaround
One of the casualties of the economic downturn was the temporary suspension of the Dodge Viper program. After all, spending money on the development of an outlandish V10-powered track weapon while the very existence of the company itself was being debated in Congress wouldn't have looked good.
After a two-year hiatus the Dodge Viper is back. This time, however, it flies under the SRT banner, a "Snoop Lion" move if ever there was one.
Fiat now has its hands in the project, but will we see the effects here? Outwardly, the answer is a resounding "no" because the 2013 SRT Viper looks every bit as mean and raw as the previous car. The enlarged SRT Viper interior, with its much better electronics and controls, is friendlier to taller drivers and shotgun passengers of any size, but this was long overdue. Nothing here smacks of an Italian takeover.
And the familiar 8.4-liter V10 still lurks underhood, now sending 640 horsepower and 600 pound-feet of torque down its driveshaft, 40 more of each than before. But for the first time, electronic traction/launch control and electronic stability control systems are standing by in case common sense goes out the window. And also because such stability systems are now required by law.
But what sort of suspension is the ESC system standing guard over? We racked a 2013 SRT Viper GTS up on our Rotary lift to find out just how different the new machine is compared to the 2009 Dodge Viper we peeked at some two years ago.
Little appears different from this view, which still consists of a double-wishbone suspension, meaty 14.3-inch brake rotors and four-piston Brembo calipers. But a quick look at the spec page reveals that the 2013 Viper front suspension's track width has increased by 1.3 inches, swelling from 61.6 to 62.9 inches.
According to SRT that's not the result of any of the hardware we're looking at here. Instead it's down to 20mm wider front tires and half-inch wider wheels with a different offset. The Viper wheel backspacing remains more or less the same, which means the extra tire width protrudes out, dragging the center of the contact patch along with it.
A closer look at the aluminum upper and lower control arms and the aluminum knuckle inspires more déjà vu. Even the stabilizer bar and drop link appear eerily similar. Clearly there has been no complete rethink here.
The steering (yellow) is of course still front-mounted and hydraulically assisted, and the ratio of 16.7:1 remains the same as before. Some other publications have reported the 2013 Viper has a quicker steering gearbox, but a close look at the specs of our departed 2009 Dodge Viper SRT-10 test car reveals precisely the same number.
According to an SRT engineer I spoke with, the greaseable upper and lower ball joints with zerk fittings (green) are used because Viper owners tend to be hands-on types who are more likely to take their car to the track and do the necessary prep and post-race maintenance themselves; they don't care to put their trust in lifetime lubrication.
We've seen this before, too. The trio of bolts that hold the lower shock bracket to the arm (yellow) and the tab for the stabilizer bar drop link (white) are repeated, mirror-image style, so a single lower control arm part number can be used on both sides of the car.
Our Viper GTS has Bilstein two-mode dampers, as evidenced by the slender wire peeking out from the top.
The Bilstein two-mode shocks also feature a remote reservoir.
A pair of eccentric cams built into the inner pivots of the lower control arm allow for adjustment of front camber and caster.
These are the same four-piston Brembo calipers with an open window for easy trackside pad replacement we've seen before, but the available SRT Track Package swaps in lightweight two-piece rotors made by Stop Tech. 2013 Vipers without the Track Package get one-piece rotors that are similar to those found on our 2009 long-term test car.
Two functional air scoops duct air toward the front tire. The inner one (blue) is round, and is clearly meant to direct cooling air to the brakes. Scroll back a few photos and you'll see a circumferential ridge built onto the end to allow the fitment of a duct hose and hose clamp by track-day users who want to get more serious about brake cooling.
The slot on the outside (green) has a less obvious function, as it shoots air toward the outer edge of the tire. This one seems like pure aero, an attempt to clean up the turbulence that comes with a massive rotating tire in the wheelhouse.
This view of the double-wishbone rear suspension also looks similar to the previous Dodge Viper, but something is fundamentally different. We can see evidence of it from this very angle, and if you know what you're looking at you'll see it in every shot that follows. I'll hold off saying anything for a couple frames to see if you can spot it.
The dual aluminum control arms appear unchanged, but appearances can be deceiving and I'm not referring to CAD drawings, so we'll go with very similar. The same can be said of the rear stabilizer bar and its drop link. Even the frame itself and its aluminum belly pan looks virtually indistinguishable at a glance.
Sometimes I miss the old driveway walkaround format I used for the 2009 Dodge Viper, but I could never take shots like this one, made possible by our Rotary lift.
Wait a minute. Wasn't the parking brake caliper mounted behind the axle centerline last time around? Shouldn't we be staring at a big red four-piston Brembo caliper from here?
That was then; this is now. For 2013 the toe link has been moved from its former location behind the axle centerline to a position in front.
There it is again. And it looks as if it has two means of adjustment: a turnbuckle and an eccentric cam. What's that all about?
Look carefully at the fences on either side of the eccentric cam to see the answer. These run horizontally, which paradoxically means this is an up-down adjustment point for bump steer, not an in-out one for toe-in. The traditional toe-in adjustment is made with the turnbuckle built into the link itself.
Adjustable rear bump steer is new for the 2013 Viper, and it's a nod to track users who want to optimize the handling of their car from track to track. But that's not the main reason for the switch from a rear-mounted toe link to this forward mount. SRT engineers tell me it was done to better optimize rear roll steer and compliance steer in general, to make this beast a bit less beastly.
The relocation of this link is what caused the brake calipers to trade places, and in so doing the aluminum rear knuckle had to be totally redesigned.
The last time I did this on a Viper in 2010 I reckoned the stabilizer bar motion ratio was 0.70:1 and the coilover spring/shock motion ratio was 0.60:1. The angle this shot was taken at differs slightly, but in real life the ratios appear unchanged. I probably underestimated them a bit last time. In any case my eyeball estimates don't matter nearly as much as the numbers on the design drawings.
I don't have much to say about this one. I just like the shot for some reason. For the record, you're looking down on the lower control arm where the lower shock mount splits into a fork and surrounds the rear drive axle.
Once again the top of the rear coilover shows a wire that tells us these are Bilstein two-mode shocks. The modes are manually selectable between "Race" and "Normal," but if you exceed 90 mph the switch to Race mode is automatic.
This hose tells us the rear shocks have remote reservoirs, too, but the reservoir canister itself is hidden behind the fender liner.
Once you ignore the new mounting location you'll start to see that this rear-mounted Brembo four-piston caliper is the same as last time, right down to the diameter of the piston pairs within (42mm and 38mm.) The same carryover status applies to the front brake calipers we saw a few frames earlier, which continue with the same 44mm and 40mm-diameter piston pairs they had before.
The 14-by-1.3-inch Stop Tech rear rotors are the same size as those in front, which means your track day spares kit just got a little less complicated. Lefts and rights will differ, though, because the directional fins within these Stop Tech rotors are curved to make them more efficient at pumping air when the car is rolling forward. But even that is merely a matter of how you orient the rotors before you bolt them to the aluminum center section.
Functional rear brake cooling ducts are built into the 2013 SRT Viper's C-pillar trim.
I hinted at this earlier, but here's the deal. The 2013 SRT Viper wears bigger tires all around: 295/50ZR18 versus 275/35R18 in front and 355/30ZR19 versus 345/30ZR19 out back. The 10.5-inch-wide forged aluminum front wheels are half an inch broader than before, but the 13-inch width of the rears represents no change.
The aforementioned SRT Track Package option on our Viper GTS brings with it Pirelli P Zero Corsa tires with a race-inspired compound instead of the standard Pirelli P Zero rubber found on Vipers without this option. The Track Package wheels they're mounted on are "ultra-lightweight multispoke Sidewinder II" wheels, which explains why, despite wider tires, this rear unit weighs 56.4 pounds instead of the 64 pounds we observed on our 2009 machine. Similarly, a new Track Pack front assembly weighs 43.4 pounds, some 8.1 pounds less than last time even though both the wheel and tire are wider.
All told, the Sidewinder II wheels, tires and the Stop Tech rotors that come with them are good for a savings of 57 pounds of total unsprung weight versus a 2013 Viper with same-sized standard-duty parts. Clearly the $3,500 SRT Viper Track Package has merit worthy of the name: better braking, more stick, less unsprung weight.
In the end, the 2013 SRT Viper isn't that different underneath from the car it replaces. By and large we're seeing the sort of generational changes you'd expect, a series of improvements that builds upon the Viper we already knew and loved in an effort to make it that much better. It's just two years late.