Does Prius III has anti-roll bars?

Here are some photos of the underside: http://priuschat.com/forums/gen-iii-2010-prius-main-forum/74666-undercarriage-photo.html

The 2010 advertising brochure doesn't mention one in the rear but there is something in the photo just ahead of the axle beam, maybe that's it?

 

I would love to put a rear anti-roll bar on my car. I had one on my MkIV GLI and GTI (both had beam rear suspensions) and they made cornering even more entertaining.

 

For the title I was expecting whether there was a rollcage inside the cab. I guess I am more use to anti-sway. I would think a stiffener would be more beneficial to the Prius, no?

 

I took a look at mine and it doesn't look right to be an anti-roll bar The way the ends are flattened and the way it is bolted it wouldn't resist torsion very well.

If I had a Prius sized BBQ-spit like the shop in the photo does, I could give you a more definitive answer. But, from what I can see looking under my 5.5 inch ground clearance car, the bar is there to provide some side to side rigidity like aftermarket strut tower braces do in the front.

The official name for the bar in the picture is
"REAR SUSPENSION BRACE SUB-ASSEMBLY" which also indicates it's a brace, not an anti-roll bar. That name is from the 2010 Toyota Repair manual

Toyota lingo for anti-roll bar is "Stabilizer Bar"

A little background on twist beam rear axles. The manufacturer can design as much anti-roll stiffness as they want into the axle itself. The lack of an anti-roll bar doesn't mean they skimped.

If anyone does add anti-roll stiffness (bar or otherwise) to the rear of a FWD car, be sure you don't add too much. You won't know you added too much until someday when you back off the throttle in a hard fast turn and then get to watch the rear of your car become the front of your car.

 

I did that with my Civic a long time ago actually - put on rear bars that were a little too thick, took a turn too fast and almost slammed sideways into a parked car. After that I had to adjust my tire pressures to compensate, so didn't have that problem again (but then I didn't drive it that crazy again either). Cornering was really nice though, esp. with sticky summer tires.

mc

 

If you stiffen the rear end on a front wheel drive car you will get understeer under accelleration.

 

Exactly!

That's what made on-ramps so much fun in the GLI. Watching that little ESP light winking all the way up.

 

Gen2 has rear stabilizer and Gen3 doesn't.
Following is a copy of my post.
-----
FYI,
Following figures are Iconic Prius rear suspension with the stabilizer bar and Auris rear suspension.
I think Auris's one (same as 2010 Prius) is stiffer eliminating to add an independent stabilizer bar.

Ken@Japan

 

Ken, can you find out what the bar in front of the Gen3 rear axle is? It doesn't look like an anti-roll bar, it looks more like a chassis stiffener like a strut brace but I can't be sure without getting under the car.


The bar shows in these pictures from another poster's thread.
http://priuschat.com/forums/gen-iii-2010-prius-main-forum/68549-photos-taken-bottom-of-my-prius.html

 

I also think the bar is a chassis stiffener.

Ken@Japan

 

TRD rear sway bar (22.6mm) from Scion XB [2008+] works, I have one on my 2010.

Forgot to get some pics when I had it on the lift, so these will have to do for now. Also, any aftermarket front and rear sways for an 08+ XB will work on the 3rd gen's. Also, a stock front sway bar from a current body style Rav4 will work and is 2mm larger (26mm) then 3rd gen stock front sway bar (24mm).

 

Thanks for the x-reference info

Are those muffler clamp looking mounts TRD parts too?

What difference have you noticed, other than less lean and most likely quicker steering response? Have you pushed it hard enough in a corner to see how your car acts when it's pushed past the limits?

 

Yes those are the parts included in the TRD installation kit. I autocross my Prius, so it gets pushed to the limits. With the RSB and Tein H-Techs (I also have some custom interior x-bracing) you can get the car to oversteer. It has totally changed the feel of the car,I love it.

 

If the car is stock, adding a rear sway isn't going to help as the rear tends to slide already (stability control will knock the car back in its place if you slide it too much). If you have a bigger front bar (which the car could use due to its massive bodyroll), then yes it would be a good idea to put a rear bar to compensate.

Do you force charge your battery when you autox? I hate how the battery is depleted after the first run!

 

I don't force charge as Auto-x'ing already builds tremendous amounts of heat in the inverter/hv transaxle/hv battery. I place the vehicle in inspection mode when I'm in the starting grid. I run in inspection mode with B mode and PWR mode activated. Oh and the RSB does help flatten the entire chassis and does allow the vehicle to turn quicker. Next up is larger front sway bar and front strut tower brace.

 

I don't do it either as I am worried about the same thing. Without the stability control disabled, a snappy car will only lose time when it slides sideways. I found it tough to run without the 15-20hp from the electric motor as they really help.

 

huh ? Prius is an oversteering car ?

 

I plan to add just rear sway bar. to fix the understeer. thanks for your post. I will order an 08 XB TRD rear sway. I have 2 race cars, can't wait to take the Prius out to track days !!

do u run staggered tires ? wider on the front, narrower at the rear ?

 

On our NHW11, 2003 Prius, I'm running:

• 195/70R14 - front
• 175/70R14 - rear

But I'm doing this for mileage and handling tests. Now that the cooler weather is returning, I'll be able to complete my tests.

Bob Wilson