I'm kinda rusty on my physics but what is the meaning of both of them exactly? In the S2000 by Mr. Carney, he says that the S2000 has similar bending rigidity to the Accord but better than the Integra and the NSX. In terms of torsional rigidity, he says that the S2000 is comparable to the Integra but is worse than the Accord and the NSX. I don't know the exact diff between the two terms but it seems that the Accord is at least the same (or better) overall in general rigidity. How come I don't feel this when I'm driving my parents 98-99 Accords?

Also, does anyone have numbers for both types of rigidity for the S2000? And how does the numbers compare with the competition (Boxster, Z4, TT, etc)? Besides the Corvette droptop, is the S2000 the stiffest roadster ever made?

 

Torsion = twist
Bending = um, bending

 

[QUOTE]Originally posted by BrotherRex
Torsion = twist

 

Bending rigidity. Example: take a vhs cassette, hold it in both hands, one hand on either end; now, try to arch to tape up in the middle(^) by pushing with your fingers of both hands which are below the tape; or you can try to bend the middle of the tape down (/) applying force with your two thumbs which are above the cassette.
What you are doing right now is testing the bending rigidity of the cassette........similar to the bending rigidity of the chassis of a car.

Torsional rigidity. Example: holding the same cassette in the same manner, try "twisting" the cassette as if you are trying to wring out a wet rag, here you are testing the torsional rigidity of the cassette....similar to the torsional rigidity of the chassis of a car.

The S2000 (at least the MY04, I am not certain about the pre 04), has greater bending rigidity than the NSX and the Honda Accord but less torsional rigidity than either of the above cars. Torsional rigidity is sacrificed in a convertible because of the absence of the rigid roof. The phenomenal bending rigidity of the S2000 is obtained to give the convertible as much of a stiff chassis as possible because of the absence of the roof.

Take a shoe box without the top (roof) and try to twist it, now do the same twisting thing after replacing the cover (roof) and you will see how much more stiff the box becomes against torsional forces. I read this shoe box example somewhere but cannot recall now where.

This is one reason so many wish there was a true hardtop or coupe version of the S available as well. But the convertible has its charms as well, as we all know.

Hope that helps in some way.

 

Thanks for the explanation. You probably got that shoebox analogy from Carney's book.

Anyone have numbers for the S2000 and how does it fare with its direct competition (Z4, TT, 350Z roadster, Boxster, etc)?

 

Ever put a car, like a Camaro convertible on a lift supported only on the frame in the center of the chassis? Notice the doors won't open? Bending rigidity or lack of. Now drive the same car up a ramp only with one of it's front tires. Notice the doors won't close? Torsional rigidity or lack of.

Keep in mind the '04 is even stiffer than previous MY's. Can't seem to find actual specs for comparative analysis. All I know is my S is the stiffest chassis I've ever driven, including the Vette, but I also have a strut bar and x-brace for whatever nominal gains. The last Vette convertible I drove had much more cowl shake over the RR Xing near my house when compared to my S which barely moves at all.

Love this car.