Rear Sway Bar

Is it a larger diameter? Tell us more about the handling!

 

Thanks for the info wayside.

For comparison, the Standard Prius has a 19.1 mm diameter rear stabilizer bar, and the Touring has a 20 mm diameter bar.

 

Subscribing...

 

So what's the big deal? I have one already, it came with the car. It's tucked up
inside the U-shaped rear suspension cross piece thingy (axle?) -- I just went
out with a flashlight and checked.

It's not like adding the front strut tower brace is it? It seems an equivalent
piece for the rear suspension would be taking up space inside the the car,
roughly where the tonneau cover cross bar is.

Could the suspension-smart members explain the dynamics of how/why
this oversize bar affects the Prius' handling and or stability. I for one haven't
a clue.

 

Here's a pretty good article about anti-roll bars (aka anti-sway bars and stabilizer bars). Note also that at the top of the article are links to other good articles about handling:

Howstuffworks

 

Assuming this is a non-touring Prius the diameter change from 19.1 to 27 mm is enormous. If I understand correctly stiffness changes to the 4th power of the diameter, so this could result in a bar that is four times stiffer. (Touring diameter is good for 20% difference from standard.)

This radical of a change could have some adverse consequences such as early oversteer. Have you tested this yet in an area you can afford to spin it? From what I can gather lifting off the throttle in a corner in the rain could be very exciting with such a large diameter bar.

 

It does seem like a huge increase. I also wonder about the effects of increasing the diameter of the rear bar by so much without also increasing the front bar too.

Howstuffworks

In this regard, I believe that Hotchkis sells this rear bar only as part of a front and rear bars kit for the Matrix/Vibe.

 

Boo,

thanks for the two references. Good stuff for tyros. They get bookmarked.

Taken together, there's enough there to get an inkling of the contribution
of sway bars in the complex, dynamic 3-D suspension equation.

 

wayside,

I'm not trying to be overly critical. I'm glad that you let us know this fits (and that itself opens up more options as you've noted.) But I did want to pass on what I gathered from looking at some sites. I would feel guilty if I remained silent and you had a nasty spin and resultant damage or injury.

What I read is that if you overdo a sway bar mod a car will handle great up until about 8/10's, then things happen very rapidly and unpredictably.

I put a front & rear sway bar kit, progressive rate springs, better shocks/struts, poly bushings and strut tower brace on my 240 and that made a huge difference in handling. (And as you mention, I spun it on purpose to get a feel for what happened at the limit of adhesion...and past it; ended up saving my car when a lady ran a light in front of me forcing a crazy swerve and resultant spin.) So I'm not at all opposed to doing suspension modifications or sway bars to the Prius.

 

for the record, go here to see what Hotchkis offers for the Corolla:

Hotchkis Sport Suspension - 2003+Corolla

As other posters have suggested, the 27mm rear bar is paired with a 29mm
front bar, both hollow.

 

BTW, Brian of BT Tech has been working on coming out with a beefed up front sway bar for the Prius. In one of the other threads here, he's discussed it briefly. I remember him saying that he was very pleased with the improved handling and reduced body roll from the prototype bar he created. But I also recall that he should have come out with it a couple of months ago. So, I don't know what's up with it.

 

Good find in finding another car that "shares" parts with the Prius.

As others have mentioned, 27mm is a huge increase from stock. But then again, stock, the Prius understeers like crazy. In my past experience with sway bars, for those who are looking for better handling without going crazy, typically upgrading both the front and rear bars similar amounts works best and gives the best balance for a daily driver.

Anyone know how big the stock Vibe bar is? I'm just guessing, but given how big the aftermarket bar is, the stock bar must be bigger than the touring bar. That should be a better compromise, especially if you don't upgrade the front bar, or a good upgrade for Touring owners.

I wonder if the front bar fits as well? Someone go and look up some part numbers.

 

Dang, guess i'll be spending some time at the salvage yards in Chula Vista this weekend

 

How about the Progress rear sway for the Matrix/Vibe/Corolla? It looks like it is 22mm.
Progress 22mm Rear Sway bar kit for 03-06 Toyota Corolla, Matrix, and Pontiac Vibe - 62.2150

 

Or the TRD rear sway for Matrix (looks like 24mm):

TOYOTA 2006 2007 2008 COROLLA MATRIX TRD REAR SWAY BAR

 

If we can get another confirmation that the 03-06 Corolla/Matrix rear sway bars fit, that will give us a pretty good number of choices for rear sway bars!

Now for the fronts...