Digging up an old thread.
After a quick search, i found a few quotes and extrapolated the relative stiffnesses to try to figure out the torsional stiffness of the Gen 2:
1992 RT-10:
"The Viper has a high driveline tunnel, which also houses structural members that help account for its outstanding
5000 lb-ft-per-degree torsional stiffness."
http://www.roadandtrack.com/new-cars/first-drives/reviews/a6319/flashback-1992-dodge-viper/
1996 Second Gen (GTS):
"The second-generation Viper included engine modifications to add power, while reducing weight by 50 pounds. The Viper chassis was reengineered to eliminate 60 pounds in comparison to its predecessor, yet provide a
25 percent increase in torsional rigidity."
http://www.drivesrt.com/news/2014/01/viper-heritage-the-first-decade.html
1996 RT-10 (Same chassis as 1996 Gen-2 GTS, but with 400hp Gen-1 engine)
"The changes, however, go deeper than cosmetics. With the goals of shaving excess weight and improving high-speed control, the Viper team was able to trim about 200 pounds from the car while improving the frame's torsional rigidity by about
25 percent."
http://www.motortrend.com/roadtests/exotic/112_9509_1996_dodge_viper/
2003 SRT-10:
"This drivetrain rests in an updated chassis that offers a
31-percent increase in torsional rigidity (Dodge claims it's stiffer than the outgoing 2002 GTS Coupe)."
http://www.edmunds.com/dodge/viper/2003/road-test.html
2003 Comp Coupe:
"The Comp Coupe team started with the 03 Viper frame, but “chopped some parts off and added a cage,” says Petersen. It has a safety cage of 1.75-inch-diameter 4130 steel tubing with a 0.095-inch wall thickness. The cage protects the driver and ties into rear suspension attachment points. It also works with special X-, V- and diagonal bracing underhood and an aluminum rear bumper to
double the car’s torsional stiffness. The effort reportedly improves the carÂ’s resistance to beam flex by 60 percent."
http://www.edmunds.com/dodge/viper/2003/road-test.html
2006 SRT-10 Coupe:
"Torsional rigidity is expected to improve by about
30 percent, which is likely to pay off with crisper handling."
http://www.motortrend.com/roadtests/coupes/112_0502_2006_dodge_charger_viper/exterior_engine.html
"Unlike most other coupe/convertible vehicles, this generation of the Viper was developed as a convertible first; therefore, the already impressive torsional rigidity of the convertible has been improved by about
30 percent with the addition of the solid roof."
http://www.car.com/content/shared/a...order_int/2/article_id_int/435/make_vch/Dodge
"Of course the Viper Coupe's real performance payoff over the roadster is its stiffer overall structure. Rather than the convention of building a convertible model from a hardtop, Dodge began with the already reinforced roadster and constructed the coupe to extremely high torsional rigidity tolerances. It features a backbone tubular space frame with separate cowl structure, plus SMC and RIM body panels, aluminum sills, RIM front and rear fascias with composite impact beams. In English, the
2003 roadster was 31 percent stiffer than the old roadster, and even more rigid than the old GTS coupe. The new coupe should be rock solid.
https://www.auto123.com/en/news/2006-dodge-viper-srt10-coupe-preview/42887/?page=5
2013 Gen V:
"Rumors that Chrysler would switch to the Alfa Romeo 8C’s platform turned out to be untrue, and the car rides on the
same steel structure as did the last generation. Its wheelbase is unchanged and the aluminum front suspension is only slightly tweaked, but the front track gets wider and the rear suspension geometry is new. (The rear suspenders are also aluminum.) More important, an underhood X-brace headlines a
50-percent increase in torsional stiffness."
http://www.caranddriver.com/news/2013-srt-viper-photos-and-info-news
"The carbon fibre X-brace under the hood improves torsional rigidity by
50 per cent" -Seems like the X-brace is the main difference to the SRT-10 chassis and primary reason it has a stiffer chassis.
http://driving.ca/dodge/viper/auto-news/news/srt-unveils-2014-viper-time-attack
"Without increasing cost, enhancing the torsional rigidity and lowering the curb weight contradict to each other.
Initially, the engineering team planned to increase the torsional rigidity 100% more than the previous generations. But due to a tight development time frame (2 years) and limited budget,
the team can only achieve a 50% rigidity enhancement in the end. You can check out our extensive data list here, the current Viper’s torsional rigidity is only
11,400 nm/deg, not very good for sports cars in this price range.
Another effort the engineering team made to lighten the weight is the V10 engine. IT is now 100 lbs lighter than the one found in previous generations.
During the design phase, at one time the engineering team even considered using aluminum to build the car chassis. But the drawback to that would lead to a $20,000 increase of the final MSRP, so the idea was abandoned. There is other reason that the aluminum chassis design is not accepted, due to the fact that when the Viper was under development, the C7 Corvette Stingray was not in the market at that time, so the benchmark is set to the C6 Corvette, and the frame of the C6 (except the Z06 and ZR1) is not made of aluminum. For your reference, the SRT Viper’s chassis is using the same OEM supplier that makes the space frame of the Chevy Corvette.
Furthermore, if Chrysler had decided to use aluminum, it is not that simple to use the same chassis design while using steel rather than aluminum. This is due to different physical characters of the aluminum, and you cannot use the same design to achieve similar strength and rigidity requirements. Therefore it needs a completely new design and new production equipment. Obviously for such a short development period and low project budget, this is impossible."
http://blogs.youwheel.com/2014/05/07/the-design-of-srt-viper-some-insider-information/
Audi R8 (2014 – )
40,000
Dodge Viper Coupe (2008 – 2010)
7,600
Dodge SRT Viper (2013 – )
11,400 - that's a 66.7% increase, which can be called '(well) over 50%' increase in torsional rigidity. If true, it's still very low and half of a 458 spider.
Ferrari 458 33,120
Ferrari 458 Spider 23,184 (70% of the Coupe)
http://blogs.youwheel.com/2014/04/25/car-body-torsional-rigidity-a-comprehensive-list/ -A more comprehensive list of various cars' torsional rigidity.
If the above is true, then so should the following (depending on how you interpret the quotes regarding the SRT-10 Coupe to determine the Gen 2's stiffness):
RT-10 (1992-1996):
5,000* - 3,569 (Calculated from above relative stiffness, this is incorrect, so the 'relative' stiffnesses are wrong)
RT-10 (1997-2002:
6,250 (25% more than Gen 1) *It's probably less since I would bet MotorTrend took the 1996 GTS' press kit and mistakenly used it for the 1996 RT-10. The GTS would have to be stiffer and IS said to be 25% stiffer than the Gen 1, so I would imagine the RT-10 is still at or slightly more than 5,000lb-ft-degree.
GTS (1996-2002):
6,250 (25% more than Gen 1)
SRT-10 Convertible:
6,550 (31% stiffer than RT-10, and stiffer than GTS *Sounds about right)
5,845 (30% softer than SRT-10 Coupe *Think its wrong)
SRT-10 Coupe (2008 – 2010):
7,600*
Comp Coupe:
11,690 (double the SRT-10)
SRT Viper (2013 – ):
11,400*
Here's a list (in order) of notable sub 10K nm/deg cars:
Lamborghini Countach 2,600
Lotus 33 3,253
Chrysler Sebring (convertible) - 4400
Ford Mustang Convertible (2003) 4,800
BMW E36 Z3 5,600
Lotus Esprit SE Turbo 5,850
Mazda MX-5 (NA 1st-gen, NB 2nd-gen) 6000
Chrysler Durango (not the latest generation) 6,800
MG MGF 7,100
Honda S2000 7,100 (rumored)
Lotus Elan 7,900
MG MGTF 8,500
Mazda MX-5 (NC 3rd-gen) 8800
Lotus Elan GRP body 8,900
Mini Cooper Convertible (1st gen) 9,000
Chevrolet Corvette C5 9,100
Mazda RX-7 (FB) 9150
Ford Mustang Convertible (2005) 9,500
http://www.s2ki.com/s2000/topic/722146-nc-miata-vs-s2000-cr/page__st__50
Other random, unverified tid bits of info:
Z06 bending frequency = 24hz
Z06 weight distribution = 51 front / 49 rear
Viper SRT10 bending frequency= 27hz
Viper SRT10 weight distribution = 48 front / 52 rear
and just for a laugh so you get an idea of how strong these cars are.....
(these might not be right)
'02 Camaro Z28 bending frequency = 14hz
'02 Camaro Z28 weight distribution = 56 front / 44 rear
'03 Mustang Cobra bending frequency = 16hz
'03 Musting Cobra weight distribution = 57 front / 43 rear
http://www.z06vette.com/forums/f5/stiffer-frame-gen-ii-viper-srt-10-viper-z06-58502/
...There's a reason why the majority of cars are unibody. Much stiffer than the frames used on the Viper. Then again, NASCAR still uses frames...
