2010 Prius feels unsettled on the highway

Chassis braces (Rude person's) will NOT help, swap the tires ( front to back inspect the tires) change tire pressure. You should find a difference.

 

I have no opinion on a Gen 3, but on the Gen 2, replacing the chassis brace with an aluminum plate was very 'calming', it eliminated wind wander and buffeting while passing.

 

A way to verify the chassis plates are doing something is to take them off and see how the car drives.

Mike

 

But Jimbo,

You don't take it off, you have a buddy come over.
You don't know which brace is on. Maybe get another test driver. But no discussions. This is not by committee.
Take several test drives with you taking a backyard break in between while your buddy makes a swap,,, or not..
(Lube the threads, use a torque wrench and all should be fine.)

What a great way to waste a Saturday afternoon.
And the only expense would be the Beer and BBQ that you will be providing after the testing results are on paper.
Then the Results Ceremony !!! Dang, wish I lived near you....

This is Blind Testing.

Publish your scientific findings!!

 

Sadly, my Gen2 was run over by a Semi trailer which ran a red light, (along with the road tractor) so I have already experienced all the blind testing I get to.

 

Actually anyone with a stock mid brace can test its effectiveness easily, just remove the bolts from one side and try it out.

 

Yeah, but that is not an expensive upgrade from the stock one.
That is removing a stock part.

 

$50 was not that expensive.
G7 Performance Stiffening Plate 04 09 Toyota Prius P N 9000 | eBay

 

"Road feel" is a very subjective metric. Even purpose-built "stiff" race cars are set up differently to suit road conditions and different driver preferences -- dry/wet, tight/loose, early/late-brakers -- to optimize driver confidence and vehicle performance.

 

Zander, they will and they do.

 

Dado,

How can you tell?

How do YOU measure this?

 

No opinion on chassis braces, but there's never been a complaint from 17"-wheel Prius owners so that's likely true.

 

It's a faith based modification system. If a person were to measure it, they would be demonstrating a lack of faith and it wouldn't work.

 

No complaints here: Prius v Five (215/45R17). One of the most neutral-tracking and handling cars I've ever driven, and that includes a number of "sports cars".

 

I described it before, several times in several threads. You're welcome to look.
Additionally, my son and several of my friends and of my son's friends, who have no idea who Rude person's is, what exactly he sells, or that PriusChat exists, have commented on their own perceptions of the improvements after I bolted on the parts described in my other posts, which include, but are not limited to, Rude person's's pieces.

 

What kind of comments have you received??

 

Depending on the mod.

The center brace caused a lot of "wow, this thing feels different now, like it floats less" and "the car is more stable in cross winds and when passing semis".

The front underbrace caused the perceived EV/gas engine transition to disappear, especially at certain speeds. "Dad, the EV icon disappeared - did the engine turn on yet? I didn't feel it like before".

The TRD rear anti-sway bar added just a li'l "bounce" to hard cornering, while simultaneously let the car corner and exit hard corners way faster. How much faster: there's a new(ish) and very tight curve on DCs' rebuilt Southeast Freeway as it crosses the 11th Street Bridge over the Anacostia River. I routinely now take that curve at around 56 - 57 indicated MPH, and often go around boy racer Mustang etc. cars when accelerating out of this two-lane curve. Pre-sway bar, I'd never take that same corner at more than about 45 MPH. One comment: "hey Dad, slow down - you're throwing me out of my seat the way you drive this thing". Another comment, from a friend: "Just 'cause you have a Super-Prius, doesn't mean you should forget about my pulled shoulder when you corner like that".
Note: without the added center brace mouted first, I would not have been able to lean on the sway bar in corners that way I can now.

After adding the front strut tower brace (Son again): "Jeez this thing tracks well - now it goes right where I point it like it's on rails".

There's a whole post where I split all these into individual pre- and post-installation observations.

 

Dado,

Pretty impressive "observations".
I have no doubt about the effectiveness of a rear anti-sway bar. That is a truly measurable modification to a car!

But all these expensive bolt-on stiffeners, (especially a little ~16" by 4" plate in the very center of the car), could be just the Placebo Effect. (Young people are particularly susceptible to suggestion, but let's not get into that...)
This Effect has been mentioned in many posts by different people.

Even if there was Static Load Testing of the stiffeners' effect on the car's structure, I doubt if you'd see much measurable difference. Have you seen Cusco's silly site trying to convince us about their products? 4mm, 6mm,,, whatever...

Only side by side Blind A-B Testing would tell if there is a real difference.

I would really like to participate in such testing!!
If I could pick which of those two identical Prius had the bolt-on stiffener, or even stiffeners,,
I'd be placing my order later the same day.

 

Maybe see if Tire Rack had an interest in selling those braces and testing them on their skidpad and road course They have done a lot of Prius testing in the past. Is there a Prius Chat member who is an employee?

Mike

Mobile on my SGH-i717

 

Bill, my observations are my own and contributed freely. I stand by them. You are welcome to your "doubts". Chacun a son gout. This world is wide enough for all of us on it.

Relatively expensive items = TRD anti-sway bar and the Cusco strut tower brace. The two Rude person's underbody braces are actually very cheap.

I'd be happy to participate in a Blind A-B test.