My car (sedan) feels the same way, especially when it is windy. I have stock sedan sport suspension with about 55k miles. The only change I have made to my suspension is Stillen sway bars. When I had them put on I asked for the to be put on soft/med, but when I saw the car on a lift I noticed they were hard/med. I had a shop change them to med front and med/hard rear. Now the car feels floaty when I am driving into the wind. The other day, when I was driving, I accelerated (floored) from 75 to about 85 and I felt like i was going to lose control. I am going to check to see if the plastic under engine/body spoiler is not properly attached and possibly catching wind. I thought this might be acting like a wing and unweighting the front suspension.

 

possibly could be that bald tire. i recently dropped the G on tein basics and put the stock wheels (with a good amount of tread left) back on, drove it home and it felt fine. next day i put new wheels w/ bald tires on just to see how it looked. drove it around and it pulled left and right. i just recently bought new tires for the wheels and they feel like i had the stockies on.

 

I had 350z htecs on my car for roughly 20k..recently swapped them out..I'd say as of recent I've experienced that shifty feeling when I hit a bump like the back might go out on me or something.

I was aiming at the fact that it might be:

1. The weather was cold so the tires were not heating up properly causing me to have less traction
2. My OEM struts were slowly dying
3. Bridgestone Potenzas are a major POS

Well I recently swapped suspensions and I no longer have this problem and my OEM struts were in decent shape..not really sure what was causing the problem. However my gut feeling is its just the harshness of the Potenza as it wears further..

-Vin

 

I think it was less than 30K when they came off the car.

It's fine, as long as you know what you're getting. I've run used 350Z unrevised springs, used Hotchkis springs, and used Tein Flex coilovers w/EDFC. Only new suspension parts I've had on this car were Tokico DSP-9's.

 

I had the occasional problem with the Tein Suspension. Every so often I would hit a bump and the rear of my car felt like it would do the Harlem shake. I went and got an alignment because the car would pull to the left when I would floor it from a dead stop (-0.8 on the drivers side and +0.8 on the passenger side ) Hopefully this will all change next week with new sways, strut bars, camber correction and toe kit. The alignment helped with the hard pulling to the left and a little with the bump steer.

 

I know it has been a month but I would like to know what happened. I have had the same problem since putting on H-techs last year. I did the camber kit for front and rear but never got around to installing the toe bolt. I am almost certain that it is my excessive toe-in condition that is caused by lowering the car(I was pretty sure that lowering makes toe in greater) I will get the toe corrected in the next couple weeks and let you all know. While I am at it I will change to some CS's instead of the H-Techs.

 

It was just a bit out of alignment on the rear tires.

I got that fixed and the issue went away.

I just get thrown around by the road now. That's bout it.

 

I had the same issue, and it turned out that I needed new front control arms. Apparently it is a fairly common problem on our cars. It would explain why you felt the alignment is changing, because it actually is. Check the bushings. ( I think that is what was worn out).

If Joker's problem is solved which it sounds like it is, my post is for others with similar problem.