If you never had your alignment checked, you should. A car that doesn't have enough positive caster (positive is tilted forward right ) will be twitchy as hell and will tend to wander all over the road. That means that it is not tracking well.

The more caster you dial into a car (steering knuckle's tilted foward) will make it stable and track well, but will also make the steering wheel feel heavier which is not necessarily a bad thing.

The bottom line is, even if your car is aligned perfectly, if hit by a 40+ mph side wind while cruising at 65+ mph, it's gonna do some weird $hit.

 

yeah allignment had entered my mind...maybe i'll get a more aggressive one while i'm at it. I had my tires replaced with stock size up front and 245 in the back...maybe that pushed it further out of allignment? just a thought

 

It does feel a little bit lighter than my 350z I'll tell you that... Thats because it is... all 350 pounds of it. Perfectly normal if you're not used to it.

 

I think it is possible for an alignment to change somewhat as the tires wear into a wear pattern. I doubt the the new tires would cause the alignment to change because they are 245. Remember that the OEM rears on this car are simular in width as a 245 tire. If your alignment adapted to your old worn tires, it wouldnt matter what tires you put on, the alignment is what it is.

You might want to reconsider going with an aggressive alignment as your tires will wear more rapidly. If I knew your current alignment spec's, I could tell you what to expect.

 

RACER is dead on with the alignment issue. When I picked up my s2k in Jan. it felt like ass on the highway. Almost exactly the same symptoms you are describing. (I bought it used FYI). The back tires were worn very unevenly as well. I replaced the rear tires, and got an alignment done, and it was night and day difference. It drives like a dream now on the highway.

Craig

 

How's your tire pressure? Check that if you haven't already before you shell out the bones for an alignment. How was the tire wear on the old tires?

 

You should have it checked. An alingment would be nice.

 

I am guessing your rear tires are too narrow. According to your sig you have 245. While the stock S02 is rated as 245 it's generally accepted that it's a VERY wide 245. Talk to Jim@tirerack.com and see what he says.

 

I know what you're talking about... I experience it sometime too and it has 100% NOTHING to do with alignment. My alignment is absolutely fine, it's been checked out within the last 1000 miles, actually. However, when I'm going to down certain roads, I feel as if my car is being blown by high gusts of wind from boths sides. I'm not being blown off the road or anything, but it feels as if a gust of wind hits my left, then right and so on... I honestly think it has to do with the road plus the traffic and the fact the car is a lot lighter than what I'm used to. When I am on I-75, which is a very well paved interstate, I don't notice this behavior. When I am on GA-400, a decently paved expressway with only 2 - 3 lanes, I notice this behavior on occasion. Nevertheless, my alignment and tires are just fine. Tires are fairly new and my alignment has been checked and to be honest, I can let go of the wheel and I ride a perfectly straight line for as long as the road is straight.

 

I think this could be an attribute more so than alignment. The rear tires on my S2000 are currently incorrect. I bought it with new tires on the rear that are 225/ 55/ 16. These are obviously not the right size.