AntiSocial

Hey guys noob here ( damn hate saying that)
Aight i gotta 06 is350 RWD. Replaced most of the rear suspension with Megan. Camber, Toe, Trac, Upper Forward, Also did poly sway bar bushings. Running oem shocks and lower control. I have extreme rear sway. At install I matched lengths of the bars to OEM bars. Seay was worse. I have sense eye balled the wheels. Took a tape measure to the rear yesterday both wheels roll true. Still sways. I made some rear adjustable coilovers with 10kg springs, Oem height or slammed. No joy. Same ride. Front i have Megan upper controls, and all bushings with Airlift bags. Ant insight would be Awesome..

Yodog

get new shocks or coilovers ?

Gville350

iTrader: (10)

First advice I'd have is to roll on underneath the car there and look to see for missing components/bolts/nuts or damaged/broken components/bolts/nuts. One thing that was not mentioned specifically about was what rear sway bar is in the car and whether or not you have end links attached to that bar onto your LCAs.

2013FSport

iTrader: (2)

With your car as low as it is, one can guarantee the OEM end link length is incorrect.

With the car at ride height you need to visually put eyes on two points of interest. The bar mount and the bar end. Pay no attention to the bar shape or curves.

What you want to see is the bar mount and the bar end are parallel to each other. If they are not parallel, the bar loses effectiveness.

Think like this for a moment; put a lug wrench to wheel nut with the bar parallel to the earth (3 o'clock / 9 o'clock). At 24" out, a person could apply maximum leverage to tighten or loosen the nut.
Now place that same bar on the same nut but with the bar at 5 or 7 o'clock. At these angles you can't apply the same force with gravity.

This is the same factor making your rear (likely front too) anti-sway bar ineffective.

Make sense?