I dont post much cause i can usually find what i need by searching, but I needs some expert help on a problem im having. Suspension mods are as follows:

BMR: front sway bar, rear sway bar, panhardbar bar, banhard bar relocation bar, lower control arms. The only adjustable peice is the panhard bar and i have it pretty well centered.

The problem is when going highways speeds of about 55mph plus, if you do a quick jerk of the wheel, or swerve out of the way of somthing- the the rear end doesnt respond for what feels like an entire second. After it does respond, it will jerk back and forth like a rubber band a couple of quick times then straighten out again. Its very hard to discribe and its very noticeable, and i could see it being very dangerous. This didnt start doing that untill i did the panhard bar and the lower control arms (i did them at the same time). I also replaced the rear wheels at that same time - went from 17x8 1/2 on 255/40/17's to 18x9 1/2 on 275/40/18's. I cant imagine it being the wheels' fault. I went under there to check and make sure everything is tight and it all appears to be real tight. I figured at the time that it was mabye all the tight parts with urithane bushings was putting the strain on the stock rear sway bar, so i put the bmr sway bar on there shortly after i discovered this problem. Unfortunatly that didnt fix it and it feels the same, so that rules that part out. I hope someone has some insight to this problem cause im gonna be lowering it pretty soon with Strano springs and Koni shocks. I bought the Strano springs already and there just sitting there waiting for the shocks which i will be ordering from Sam also. ANYONE with ideas, let me know, thanks!

Also, i do have subframe connectors (bmr tubular weld in's) and strut tower brace. And the front tires are 255/40/17.

 

The new springs and most def the shocks will really help.

Poly bushings on tubular lower control arms will also increase roll stifness an may have something to do with what you are experiencing

 

Well i just read a post about a guy who said his rear end felt "spongy". He just did the lower control arms with relocation brackets and it sounds like he experienced the same as me. Is it possible that no that the whole rear end is stiff and now it may be the tires flexing like that?

 

The LCA's you have bind the suspension in roll, and that makes things kind of funky when you toss the car around, hence the reason we don't run poly/poly LCA's.

Further, when they bind they store up energy that kind of springs loose all @ once. As poor as the shocks are, that makes things worse. Better shocks do a lot of things, one is slow the roll-rate generation down which makes the car more stable and solid.

And finally, the bar combo. The front bar is fine when teamed with a 19mm rear. The rear bar is fine when teamed with a bigger front. But 32/21 (or 22), or 35/25 type combinations are, IMO to rear-biased in terms of roll stiffness.

 

Thanks for the speedy response, I guess what ill do now is wait to see how well the shocks and springs stabilize everything and go from there. Thanks again!

 

I mistakenly installed a 35/25 front/rear sway bar combo - thinking bigger is better - I was wrong. The car handled poorly with the rear being the major problem.

Sam told me to go back down to either 19 or 21 on the rear - that fixed the problem - truly amazing what a couple mm's either way can do...

 

Well, it started doing this before i installed the stiffer rear sway bar, i had the stocker on there and it was doing this. Also after putting the rear sway bar on, im a lot happier with the handling now. It handles turns great, i just have to watch it when i want to cut someone off who's doing 55 in the fast lane...

 

It's definitely shocks....... and when you fix those, you'll likely find the rear bar too big vs. the front (or the front too small vs. the rear).

 

My 99 WS6 liked to wag its tail at highway speeds.

It had no modifications. At highway speeds, turning the wheel caused a delayed reaction with the rear. A split second after turning, the rear end seemed to react. The delayed reaction is definitly concerting.

I installed a shock tower brace and that fixed the problem.

Side question: How big are the WS6 sway bars?

 

After shocks check your axle bearings. If they are going out you will have a squirley rear as well.i