dampers only

[bribri]

I have a 2010 yaris hatch and notice the car wallowing over dip when cornering hard.would changing the rear shock help or will i have to go front and rear?

[MUSKOKA800]

I would suggest that you start with a rear anti-sway bar. Several brands are available and any will provide a massive improvement in the cornering ability/stability of your Yaris without sacrificing any ride comfort. I chose the TRD bar which I installed before my other suspension upgrades. It took me 20 minutes to install on the driveway at home with only simple hand tools.

Rear anti-sway bar = great bang for the buck! Every Yaris should have one.

[WeeYari]

+1 to rear sway. Will stiffen her up quite a bit.

The issue is not with shocks/struts. The OEM spring rate is very soft. Replacing dampers will not help. You need to address the stiffness, which is the springs.

[bribri]

It seem when the springs are loaded, the dampers dont damp enough. On a straight road (springs slightly loaded ) the shocks are fine. I have a 23 mm sway. Is ok to replace the rears shocks only?

[Bluevitz-rs]

You'll notice more from the fronts only than the rears.

I went all winter with stock fronts struts and springs with TRD shocks rear + TRD sway bar and had the same wallowing in hard cornering. But I also have puerto rico spec front and rear sway bars so I have tons of roll stiffness.

I put my koni's back on and it's now solid through corners.

Stock spring + Koni's (or some other high end adjustable strut or shock) will out handle Lowering spring + stock struts and shock every day of the week.

I know. I've tried it.

[MUSKOKA800]

It seem when the springs are loaded, the dampers dont damp enough. On a straight road (springs slightly loaded ) the shocks are fine. I have a 23 mm sway. Is ok to replace the rears shocks only?

In that case you might tray a pair of KYB GR2 rear shocks (see TireRack).
They are designed as OEM replacement but do have increased rebound damping. I used a full set on my Talon with Eibach lowering springs and it rode well and handled nicely. They're inexpensive as well.
The next step would be TRD or Tokico dampers. But both are valved considerably stiffer so puting them in the rear alone may be a serious mis-match with OEM front struts. Also, I'm not sure you can buy the TRD rears separately.

[bribri]

thanks