Why are S2000s twitchy?

[Grant]

I've driven a lot of cars (including an S2000-powered NA Miata), and the S2000 stands out as one of the twitchiest at the limit, with very fast steering input required to control its oversteer. Clearly they can be made to handle very well, so could anyone who's sorted one shed some light on why this is?

In stock-ish form I've noticed from DAQ their corner entry speeds are quite low, as drivers cannot shave speed off on corner entry without excessive oversteer.

I know they altered bump steer geometry in the later years, but the 2006 I drove still felt unusually twitchy to me. The only S2000 I've driven that didn't feel twitchy to me was an AP1 with a wing, but it wasn't clear if the core of the problem was aerodynamics or the wing was just covering for something else.

Thanks.

[seanshepard]

I don't think stock tire size s2000s are very twitchy, especially ap2's. Once you go something like 255 square, they oversteer pretty hard. Good tires, a big front sway bar, and quick hands help.

A rear wing completely solves the issue. S2000s were not designed in a wind tunnel. A rear wing will turn it into an understeering car.

[Brett B.]

I know there were hard-part suspension changes to the AP2 model, but I don't exactly know what they were. That took a lot of the twitchiness out of them, but they still can benefit from a wing for hardcore track use. 

This photo says a lot. Miatas on the left. S2000s on the right.