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Torsional stiffness in Newton Meters for the NSX?

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HONDA_RJJ

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Curious how it stacks up between different NSXs and other cars
I was watching top gear when they compared the DB9 to the convertible version and it got me thinking about it. Looking for the following or if differnt also the NA1 NSX-R, S, Zanardi, S ZERO, NSX-R GT, or whatever other models the made.

Thanks

NA1 NSX in NM
NA1 NSX-T in NM
NA2 NSX in NM
NA2 NSX-T in NM
NA2 NSX-R in NM
 
HONDA_RJJ said:
Curious how it stacks up between different NSXs and other cars
I was watching top gear when they compared the DB9 to the convertible version and it got me thinking about it. Looking for the following or if differnt also the NA1 NSX-R, S, Zanardi, S ZERO, NSX-R GT, or whatever other models the made.

Thanks

NA1 NSX in NM
NA1 NSX-T in NM
NA2 NSX in NM
NA2 NSX-T in NM
NA2 NSX-R in NM
Click to expand...
Would be very interesting to know.
I vaguely recall it being mentioned before don't know if it was on prime though.
 
Would be interested in that too.

I do know that when the NSX came out, Honda said the chassis torsional stiffness was (at least) 50% better than the Porsche 911.
If you have ever seen a wrecked and cut up NSX, you might have seen how thick some of the NSX chassis parts are near the front firewall.

This of course, was for the coupe. When the NSX-T came out, the sidesills of the NSX were strengthened and quite a bit too. Of course, with the open roof the total stiffness was reduced.
However, I do not know if the 1997+ couples use the same sidesills as the NSX-T. If so, it would mean that the 97+ coupes would be the strongest NSX models in existence.

The main weakness IMHO has always been the fact that the two front chassis bars were not interconnected at the front. The front bumper beam does connect them, but since those connections points are not really fixed, it does not have the same effect as the NSX-R front chassis bars or the STMPO front chassis bars.
 
I've searched this before and wasn't able to find anything...
 
Bump would love to hear some figures.
I had a 91 coupe and now 97-T with STMPO braces, front and rear tower brace and its obviously no way near as stiff. I've never driven 02+, I'm sure they would improved again.
 
I could not find anything on the nsx but I found this list:

and this link http://www.cadanda.com/CAD_PACE_1__67-75.pdf

Alfa 159 - 31.400Nm/degree
Aston Martin DB9 Coupe 27,000 Nm/deg
Aston Martin DB9 Convertible 15,500 Nm/deg
Aston Martin Vanquish 28,500 Nm/deg
Audi TT Coupe 19,000 Nm/deg
Bugatti EB110 - 19,000 Nm/degree
BMW E36 Touring 10,900 Nm/deg
BMW E36 Z3 5,600 Nm/deg
BMW E46 Sedan (w/o folding seats) 18,000 Nm/deg
BMW E46 Sedan (w/folding seats) 13,000 Nm/deg
BMW E46 Wagon (w/folding seats) 14,000 Nm/deg
BMW E46 Coupe (w/folding seats) 12,500 Nm/deg
BMW E46 Convertible 10,500 Nm/deg
BMW X5 (2004) - 23,100 Nm/degree
BMW E90: 22,500 Nm/deg
BMW Z4 Coupe, 32,000Nm/degree
BMW Z4 Roadster: 14,500 Nm/deg
Bugatti Veyron - 60,000 Nm/degree
Chrysler Crossfire 20,140 Nm/deg
Chrysler Durango 6,800 Nm/deg
Chevrolet Corvette C5 9,100 Nm/deg
Dodge Viper Coupe 7,600 Nm/deg
Ferrari 360 Spider 8,500 Nm/deg
Ford GT: 27,100 Nm/deg
Ford GT40 MkI 17,000 Nm/deg
Ford Mustang 2003 16,000 Nm/deg
Ford Mustang 2005 21,000 Nm/deg
Ford Mustang Convertible (2003) 4,800 Nm/deg
Ford Mustang Convertible (2005) 9,500 Nm/deg
Jaguar X-Type Sedan 22,000 Nm/deg
Jaguar X-Type Estate 16,319 Nm/deg
Koenigsegg - 28.100 Nm/degree
Lambo Murcielago 20,000 Nm/deg
Lotus Elan 7,900 Nm/deg
Lotus Elan GRP body 8,900 Nm/deg
Lotus Elise 10,000 Nm/deg
Lotus Elise 111s 11,000 Nm/deg
Lotus Esprit SE Turbo 5,850 Nm/deg
Maserati QP - 18.000 nm/degree
McLaren F1 13,500 Nm/deg
Mercedes SL - With top down 17,000 Nm/deg, with top up 21,000 Nm/deg
Mini (2003) 24,500 Nm/deg
Pagani Zonda C12 S 26,300 Nm/deg
Pagani Zonda F - 27,000 Nm/degree
Porsche 911 Turbo (2000) 13,500 Nm/deg
Porsche 959 12,900 Nm/deg
Porsche Carrera GT - 26,000Nm/degree
Rolls-Royce Phantom - 40,500 Nm/degree
Volvo S60 20,000 Nm/deg
Audi A2: 11,900 Nm/deg
Audi A8: 25,000 Nm/deg
Audi TT: 10,000 Nm/deg (22Hz)
Golf V GTI: 25,000 Nm/deg
Chevrolet Cobalt: 28 Hz
Ferrari 360: 1,474 kgm/degree (bending: 1,032 kg/mm)
Ferrari 355: 1,024 kgm/degree (bending: 727 kg/mm)
Ferrari 430: supposedly 20% higher than 360
Renault Sport Spider: 10,000 Nm/degree
Volvo S80: 18,600 Nm/deg
Koenigsegg CC-8: 28,100 Nm/deg
Porsche 911 Turbo 996: 27,000 Nm/deg
Porsche 911 Turbo 996 Convertible: 11,600 Nm/deg
Porsche 911 Carrera Type 997: 33,000 Nm/deg
Lotus Elise S2 Exige (2004): 10,500 Nm/deg
Volkswagen Fox: 17,941 Nm/deg
VW Phaeton - 37,000 Nm/degree
VW Passat (2006) - 32,400 Nm/degree
Ferrari F50: 34,600 Nm/deg
Lambo Gallardo: 23000 Nm/deg
Mazda Rx-8: 30,000 Nm/deg
Mazda Rx-7: ~15,000 Nm/deg
Mazda RX8 - 30,000 Nm/degree
Saab 9-3 Sportcombi - 21,000 Nm/degree
Opel Astra - 12,000 Nm/degree
Land rover Freelander 2 - 28,000 Nm/degree
Lamborghini Countach 2,600 Nm/deg
Ford Focus 3d 19.600 Nm/deg
Ford Focus 5d 17.900 Nm/deg
 
Last edited:
fenixv8 said:
I could not find anything on the nsx but I found this list:

and this link http://www.cadanda.com/CAD_PACE_1__67-75.pdf

Alfa 159 - 31.400Nm/degree
Aston Martin DB9 Coupe 27,000 Nm/deg
Aston Martin DB9 Convertible 15,500 Nm/deg
Aston Martin Vanquish 28,500 Nm/deg
Audi TT Coupe 19,000 Nm/deg
Bugatti EB110 - 19,000 Nm/degree
BMW E36 Touring 10,900 Nm/deg
BMW E36 Z3 5,600 Nm/deg
BMW E46 Sedan (w/o folding seats) 18,000 Nm/deg
BMW E46 Sedan (w/folding seats) 13,000 Nm/deg
BMW E46 Wagon (w/folding seats) 14,000 Nm/deg
BMW E46 Coupe (w/folding seats) 12,500 Nm/deg
BMW E46 Convertible 10,500 Nm/deg
BMW X5 (2004) - 23,100 Nm/degree
BMW E90: 22,500 Nm/deg
BMW Z4 Coupe, 32,000Nm/degree
BMW Z4 Roadster: 14,500 Nm/deg
Bugatti Veyron - 60,000 Nm/degree
Chrysler Crossfire 20,140 Nm/deg
Chrysler Durango 6,800 Nm/deg
Chevrolet Corvette C5 9,100 Nm/deg
Dodge Viper Coupe 7,600 Nm/deg
Ferrari 360 Spider 8,500 Nm/deg
Ford GT: 27,100 Nm/deg
Ford GT40 MkI 17,000 Nm/deg
Ford Mustang 2003 16,000 Nm/deg
Ford Mustang 2005 21,000 Nm/deg
Ford Mustang Convertible (2003) 4,800 Nm/deg
Ford Mustang Convertible (2005) 9,500 Nm/deg
Jaguar X-Type Sedan 22,000 Nm/deg
Jaguar X-Type Estate 16,319 Nm/deg
Koenigsegg - 28.100 Nm/degree
Lambo Murcielago 20,000 Nm/deg
Lotus Elan 7,900 Nm/deg
Lotus Elan GRP body 8,900 Nm/deg
Lotus Elise 10,000 Nm/deg
Lotus Elise 111s 11,000 Nm/deg
Lotus Esprit SE Turbo 5,850 Nm/deg
Maserati QP - 18.000 nm/degree
McLaren F1 13,500 Nm/deg
Mercedes SL - With top down 17,000 Nm/deg, with top up 21,000 Nm/deg
Mini (2003) 24,500 Nm/deg
Pagani Zonda C12 S 26,300 Nm/deg
Pagani Zonda F - 27,000 Nm/degree
Porsche 911 Turbo (2000) 13,500 Nm/deg
Porsche 959 12,900 Nm/deg
Porsche Carrera GT - 26,000Nm/degree
Rolls-Royce Phantom - 40,500 Nm/degree
Volvo S60 20,000 Nm/deg
Audi A2: 11,900 Nm/deg
Audi A8: 25,000 Nm/deg
Audi TT: 10,000 Nm/deg (22Hz)
Golf V GTI: 25,000 Nm/deg
Chevrolet Cobalt: 28 Hz
Ferrari 360: 1,474 kgm/degree (bending: 1,032 kg/mm)
Ferrari 355: 1,024 kgm/degree (bending: 727 kg/mm)
Ferrari 430: supposedly 20% higher than 360
Renault Sport Spider: 10,000 Nm/degree
Volvo S80: 18,600 Nm/deg
Koenigsegg CC-8: 28,100 Nm/deg
Porsche 911 Turbo 996: 27,000 Nm/deg
Porsche 911 Turbo 996 Convertible: 11,600 Nm/deg
Porsche 911 Carrera Type 997: 33,000 Nm/deg
Lotus Elise S2 Exige (2004): 10,500 Nm/deg
Volkswagen Fox: 17,941 Nm/deg
VW Phaeton - 37,000 Nm/degree
VW Passat (2006) - 32,400 Nm/degree
Ferrari F50: 34,600 Nm/deg
Lambo Gallardo: 23000 Nm/deg
Mazda Rx-8: 30,000 Nm/deg
Mazda Rx-7: ~15,000 Nm/deg
Mazda RX8 - 30,000 Nm/degree
Saab 9-3 Sportcombi - 21,000 Nm/degree
Opel Astra - 12,000 Nm/degree
Land rover Freelander 2 - 28,000 Nm/degree
Lamborghini Countach 2,600 Nm/deg
Ford Focus 3d 19.600 Nm/deg
Ford Focus 5d 17.900 Nm/deg
Click to expand...

Interesting read. especially the VW Golf, stiffer than most exotics on the list, apart from the Lamborgini Countach which must be made with Jello.
 
Do we have the NA1 NSX coupe and the NC1 Torsional Rigidity number?
I remember I had the number for the NA1 but I lost it :(

S2000 - 7,100 nm/deg
2016 10 gen Civic: 35,975 nm/deg
 
okay, the above was me and I did some really bad maths in my head. In my defence, I was just about to go to sleep and I'm terrible at mental arithmetic (always use a calculator kids).

so. 3.2 x 10^5 kg.m^2 is the same as 320,000 kg.m^2

if we multiply this by 9.81 to get it into newtons (N) we get 3,139,200 N.m^2 / RAD

to get this into degrees. 1 Radian = 180/pi = 57.3 (ish) so we get

54789.38 N.m^2 / degree

.....my bad everyone.

(although someone might wanna check the above since my history of unit conversions is apparently a bit dicey)

not sure why the link shows units in N.m/degree and Honda shows it in N.m^2/degree though, I don't know how they would relate to each other so the figure above seems fairly meaningless as a comparison :/ I have never seen torsional stiffness expressed as pressure/Rad before as opposed to torque/degree Maybe someone can fill us in?
 
Last edited:
This is all I found on the units. FPS is foot, pound, second, and SI is International Units (probably French? like FIA or something). SI is the same as MKG which is meter, kilogram, second. So N.m/radius is the metric expression of newton meter/radius which makes more sense. I'm not sure why its abbreviated as N.m instead of N m or N-m. Maybe it's just an old way to write the unit?

1675774095573.png
 
apologies, perhaps I wasn't clear. Its the squared part of N.m^2 that i have issue with :) instead of the usual N.m

N.m/degree is torque per angle, which makes sense

N.m^2 / degree is pressure per angle, which doesn't make sense to me :)

the dot is just a mathematical way of writing x or multiplication symbol :)
 
Your unit confusion is caused by mixing your equations / definitions. Specifically torsional stiffness and Torsional rigidity.

Torsional stiffness which is N.m/rad and torsional rigidity which is Nm^2/rad. The two are directly related. In the case of a simple round bar, torsional stiffness is the stiffness per unit length. Torsional rigidity is just the torsional stiffness value time the length of a sample. This reflects the fact that a bar of fixed cross section and modulus that is twice as long will have twice as much angular deflection.

Deflection angle = (torque x length) / torsional rigidity = torque/torsional stiffness

Its a rather confusing distinction; also to be confused with the torsional constant which is directly related; but, different.

Rad is radian and 2xPi= 6.28 radians in a circle =360 deg. Radians is not a metric thing, its the preferred angular measurement if you have to do integrals or derivatives. Degrees just doesn't work in math.
 
Ah okay, I've seen both terms used synonymously, even in text books :s but what you wrote makes sense. Thanks for clearing that up.

Doesn't make sense why N.m/angle is often used (as per the above link). Torsional stiffness seems like a pretty silly thing to quote for the entirety of a car (or car body) as it will change with geometry, amongst other things. Makes sense why Honda quoted torsional rigidity though
 
Last edited:
Actually, torsional stiffness is probably the more representative number. If you approximate the car body as a rectangular box section and clamp one end and then twist the other end, the longer the box section the more angular twist you will get. Take the hypothetical case of some odd customizer who decided to create a stretch NSX by sectioning the body and adding the center section of a sacrificed NSX to create a 4 door NSX. Done perfectly, this extended NSX could have a uniform body section with the same torsional rigidity. However, because it is now 1.5 m longer it will, like a longer torsion bar, be easier to twist the body with the result that the torsional stiffness will go down.

Torsional rigidity is just GxJ where G is the modulus of elasticity and J is the torsional constant which is based upon the X and Y dimensions of the object; but, does no consider Z - the length of the object. Two cars could have exactly the same torsional rigidity value; but, the one with the longer wheel base will have less torsional stiffness . If what you are concerned about is how much the body deflects at the suspension points then torsional stiffness is what you should be looking at.
 
Good to know engineering is in no danger of being replaced by AI. Chat GPT completely ignored the m to m^2 and also the kg to N conversion.

54789.38 N-m^2/deg i believe is correct, Old Guy above is correct in the difference between torsional stiffness and torsional rigidity. To convert one to the other we just need the dimension between points, using the 2530mm wheelbase converted to m gives 21656 N-m/deg. I'm assuming this is for the coupe, it would be interesting to see how the targa compares.

You can compare this to the table above and see that for it's day it looks like a pretty good value, I guess Senna was right to recommend the chassis be stiffened!
 

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