Thoughts on TRD Rear Sway bar....

I like your write up on the TRD rear sway bar, have you consider just adding this simple underbrace from Tanabe Sustec TUB135F, it WILL tighten the turn and less body roll. I am also on stock springs and struts, this add on worth a try. I bought this from Amazon, if you are not happy with it you can return it, here is the link.

 

I have both the TRD rear bar and the Sustec front brace. Both are useful but the TRD rear bar gives the greatest gain in performance.

 

I use my 2015 Prius with 17" rims for delirium of The Chicago Tribune, and a lot of my 500+ papers get delivered in small courts.
I am constantly pulling in, and backing out.
What I noticed immediately was how flatter the car stayed. That is the only difference. No increase in harshness.
My next move is ordering HD progressive rate rear springs from Valley Spring Works.
I may still install a Tanabe SFB, but I will decide that after the springs
Bottom line on the TRD RSB is this - "buy it!"

 

Sorry about the typos :

...17" rims for DELIVERY...
and

...still install a Tanabe FSB...

 

I recently added Rude person's's version (plus the center brace), and I concur; the 3rd gen Prius' body roll is indeed a function of chassis flex, and is mitigated by bracing. Now body roll is further reduced from where it was before, but it is hard to isolate which part did the lion's share, between the Cusco STB and both Rude person's underbody braces.

That said, I feel that the car's current attitude is a bit more high-strung than what I feel is appropriate for this kind of vehicle, and I might do some experiments with the center brace and feed back in better detail at some other time.

As noted in some other threads, chassis flex/"flutter" is often a designed-in signal for the understeer/oversteer transition. Oftentimes the problem is that the signal is premature, which is a reason people tune that with braces. As of right now, it feels like this signal has mostly been tuned out, or rather, tuned out a little too much for my tastes for a everyday/long-trip-driver. I need to take time and hit some twisties and see if this is a matter of my own acclimation, of waiting for the new components to "wear-in" to a softer flex, or it really is a bit much.

 

Toyota OEM rear sway bar.
I also repacked the end links.
They were dry and hardly noticed the OEM grease.

To repack, if you chose to do it. Remove the gold spiral ring on the botton of the boot.
I used a rounded tip dental tool so as not to tear the boot.

Yes my boot was deformed as well. It did not straighten out after I removed and replaced it.

The only problem with the extra grease is that it's hard to torque the bolt with it spinning.
So I used the hex key and box wrench. It's tight but not precise on the torque spec.

The ride has improved. The steering feels a little tighter. Very nice.

I hope that the free moving greased links will now remove what people have said about the clunk sound.
BECAUSE before I greased/repacked them they were very hard to move the ball in the link. Almost a clunk in my hand. Now with the new extra grease they are smooth to move around. They still appear hard but don't jump to one side when I press hard to move them.

My2cents