The Z4M-roadster, which is more rigid than an E46 M3 coupe, is easily more rigid than the S2000. Even the regular Z4 is more rigid than an S2000.

 

[QUOTE=plokivos,Jun 28 2007, 11:59 AM] use the last one.

 

I think the s2000 is relatively rigid, ocnsidering it's a convertible. But there is definitely room to improve imo

 

regarding the list, the ferraris and mclaren have less torsional rigidity than ford mustang? how is this possible

Ferrari F360 Modena: 14,439 Nm/degr

 

Its also worth noting that your 03 has a much stiffer suspension than any of the 04+ cars. IIRC, the 06/07 cars are softer yet again than the 04/05.

 

Try driving around different droptop. When I drive my daily car which is a miata I understand what magazine praise about.

 

I guess the only way to put this to rest is to have someone test the torsional rigidity of our chassis. Is this a difficult task? Can someone on the board perform this test for our sanities' sake lol?

Everyone in this thread has good intentions but some of those numbers seem hokey like what the guy a couple of posts above pointed out with the Ferraris and Mustangs.

Also, are those Z4 numbers official or unconfirmed values from scouring over the web? I had driven the Z4 and it did not feel any stiffer. Both cars weigh similarly, yet the S2000 is endearingly tossable and feels much lighter on its feet. Turn in is very direct and the S2000 is a "point and shoot" go-kart machine. Is this a function of just a stiff chassis? Or a combination of that plus suspension tuning plus weight distribution plus low polar inertia?? Sorry, for the lack of understanding but just trying to get to the bottom of this rigidity issue.

I do have 90k miles on the car and those miles have been daily-driven hard on shitty and gouged up NY roads, so I guess it's possible that what Ive been feeling lately is the result of bushing and shock absorber wear. Will ask Billman when I see him in a couple of weeks.

 

The numbers should be out there in the format of newton-meters/degree.

Automakers check that during stress testing of the chassis.

 

[QUOTE=AlpineFD,Jun 30 2007, 08:10 PM] regarding the list, the ferraris and mclaren have less torsional rigidity than ford mustang? how is this possible

Ferrari F360 Modena: 14,439 Nm/degr

 

The values for the Ferrari's seems right. The 360 Modena's structual rigidity had to be around 21k-23k Nm/degree because Ford claimed that the GT was 40% stiffer and the GT according to Ford has a torsional rigidity of 29000 nm/degree.

The guy who came up with the value for the McLaren has a book written about the car, so I think we can safely assume that the value of 13500 Nm/degree is accurate. Don't forget that a Lotus Espirit of the time had a torsional rigidity that was around 5800 Nm/degree so that McLaren is 250% better. I guess chassis technology has moved on.