Any Yaris hatch rear suspension tweeks?

[woof]

I got my black hatch about two months ago and am loving it. I traded my '05 xB for it and miss it in a way. I had a Progress Tech rear sway on the xB that really improved the handling. I was hoping the bar would fit the Yaris but NO WAY. The Yaris hatch has so little room for the rear suspension that anything add-on appears limited to springs.

Are springs the only real suspension tweek? I was hoping to adjust the rear suspension only and springs would be at all four corners and significantly lower the vehicle--which I would like to avoid.

Any suggestions?

[paultyler_82]

There are Sway bars out for the Yaris Hatch, but as of now, they're all imported parts and somewhat pricey... check with the sponsors!

www.c2auto.com and www.bulletproofautomotive.com

[Pars]

Are you sure you need a thicker rear swaybar? The rear end already seems loose enough when over doing it around the turns.

[Chris07LB]

Are you sure you need a thicker rear swaybar? The rear end already seems loose enough when over doing it around the turns.


Hence the reason/need for a sway bar..

[Chris07LB]

Are springs the only real suspension tweek? I was hoping to adjust the rear suspension only and springs would be at all four corners and significantly lower the vehicle--which I would like to avoid.

Any suggestions?

What about coilovers? Cusco and Tein have some, and im guessing even set at stock ride height (which seems what you want by your post), the suspension should still be a bit stiffer depending on what spring rate comes in either kit.

Get in touch with our Supporting Vendors here, they will get you going. :thumbsup:

FYI - I think John @ Bulletproof is still honoring his discount sale that was due on the 30th. :wink:

[keesue]

For what its worth, there is a racing suspension engineer who promoted the notion of tuning the rear end with springs and shocks and not using a sway bar (on lighter cars). I watched an autocross with two identical cars set up with/without bars in the rear and the suspension tuned car one hands down. Lowering the center of gravity with shorter firmer springs may be the way to go. I'm actually leaning (pun intentional) toward lowering the car with high quality shocks and springs with no sway bar - Sport Bilsteins or KYBs would be nice. I seem to recall Tokiko shocks too.

[ChinoCharles]

There are also rear strut tower bars available, and a rear performance bar that mounts within the rear bumper.

[keesue]

Ah...I saw that. I'll be that's the equivalent of rear tuning for the Yaris...hmmmm.....they have been racing the Yaris in Japan and they know what's what. I'll just bet that's just the tuning tip for this.

[Pars]

Hence the reason/need for a sway bar..

please explain?

[Chris07LB]

please explain?

Sway Bar - Stabilizer bars are part of a car's suspension system. They are sometimes also called anti-sway bars or anti-roll bars. Their purpose in life is to try to keep the car's body from "rolling" in a sharp turn.
Think about what happens to a car in a sharp turn. If you are inside the car, you know that your body gets pulled toward the outside of the turn. The same thing is happening to all the parts of the car. So the part of the car on the outside of the turn gets pushed down toward the road and the part of the car on the inside of the turn rises up. In other words, the body of the car "rolls" 10 or 20 or 30 degrees toward the outside of the turn. If you take a turn fast enough, the tires on the inside of the turn actually rise off the road and the car flips over.

Roll is bad. It tends to put more weight on the outside tires and less weigh on the inside tires, reducing traction. It also messes up steering. What you would like is for the body of the car to remain flat through a turn so that the weight stays distributed evenly on all four tires.

A stabilizer bar tries to keep the car's body flat by moving force from one side of the body to another. To picture how a stabilizer bar works, imagine a metal rod that is an inch or two (2 to 5 cm) in diameter. If your front tires are 5 feet (1.6 meters) apart, make the rod about 4 feet long. Attach the rod to the frame of the car in front of the front tires, but attach it with bushings in such a way that it can rotate. Now attach arms from the rod to the front suspension member on both sides.

When you go into a turn now, the front suspension member of the outside of the turn gets pushed upward. The arm of the sway bar gets pushed upward, and this applies torsion to the rod. The torsion them moves the arm at the other end of the rod, and this causes the suspension on the other side of the car to compress as well. The car's body tends to stay flat in the turn.

If you don't have a stabilizer bar, you tend to have a lot of trouble with body roll in a turn. If you have too much stabilizer bar, you tend to lose independence between the suspension members on both sides of the car. When one wheel hits a bump, the stabilizer bar transmits the bump to the other side of the car as well, which is not what you want. The ideal is to find a setting that reduces body roll but does not hurt the independence of the tires.

[nsmitchell]

^^^ Great post! I never actually understood how they worked. I suppose they are only for intense cornering. Like wheels lifting and such. Are there any other benefits to anti-sway bars? How about strut tower braces?

[Pars]

Nice post, especially the last paragraph. I believe the 07 Yaris already has stabilizer bars both up front and back and they seem to be tweaked perfectly. In my opinion, if someone was to replace the stock bars with thicker ones, it'd make the car tail happy which would be a very bad setup for the streets... Like you said, too much sway bar can be a bad thing.

Granted, the rear sway bar can be balanced by putting an equally ridged sway bar up front, but there's a sweet spot and you need to let the individual wheels do their thing. In most modern suspension system the wheels are actually designed to step out when going around a turn, in order to maximized on the tire's grip. Too much sway bar can also negate that effect.

In my old double wishbone Civic, it was a big problem, cause the sway bars were mounted directly to the control arms that allowed the wheel to step out during a turn. That was the primary reason I didn't have any swaybars in my 98 Civic hatch, but the advance suspension setup along with the tight springs/shocks and wide wheel was more then adequate to keep the car flat, no matter how hard you tried to flip it over. That car was amazing around the turns, especially in bad weather, where the suspension setup allowed all the individual wheels to maximize on traction no matter how hard it was leaning into the turn. The Accord has the same suspension setup and it's probably the biggest reason why C&D once again put the Accord on their 10best, when logically, the Camry should have been there.

[Chris07LB]

FYI - I didnt type that, it was cut and paste from doing a simple Google search.

[keesue]

The balancing act is true. I think the racing experience on the Yaris in Japan produced that rear bar under the bumper for suspension tuning. I sure they even designed the car with that in mind. The aftermarket products produce a nice revenue stream. Using this bar with the shock tower bar for chasis stability one would have the best of both worlds - taking the guess work out of things. Guessin' with sway bars can produce some undesired results. I think I'm going to look deeper into that bar. I'll let youse guys know if you want...

[Biggie™]

Are you sure you need a thicker rear swaybar? The rear end already seems loose enough when over doing it around the turns.

Hence the reason/need for a sway bar..

More rear swaybar will increase oversteer, making the car even more "loose". If people are having issues with the back coming around, more spring /swaybar in the front is needed to balance that out. :biggrin:

[keesue]

Looks like that under-the-bumper bar was for additional chassis rigidity not for suspension tuning as such; and, the torsion bar is, in fact, the sway bar - confirming the above.

[Pars]

Looks like that under-the-bumper bar was for additional chassis rigidity not for suspension tuning as such; and, the torsion bar is, in fact, the sway bar - confirming the above.


If the bar up front is for chassis rigidity, it should be called a strut bar, not a sway bar.

But it's good to know that the Yaris naturally has good balance without the aid of swaybars. That way, it can be farther be tweaked by sprinkling some swaybars or extra strut bars. Personally, I think it's perfect as is, but there's those who probably want a tail happy car for the race track. In which case, be careful, the chassis is a bit on the short side. I used to have a 84 CRX with Jackson Racing treatment. The car was incredibly quick around the turn, but it was just a quick to rotate on you without any warning.

[keesue]

[QUOTE=Pars;41736]If the bar up front is for chassis rigidity, it should be called a strut bar, not a sway bar.

Sorry, I was referring to the rear under-the-bumper bar.

[Ran Kizama]

I would like to see what's available for adjusting the rear as well. As the car sits now, my Yaris tends to kick the rear out on turns if I take them too fast. I'm thinking that a better shock/strut setup would be good first. I thought about a front sway bar, but I think that'll just make me plow into the corner.

[eTiMaGo]

I'm stil not cofortable enough to really push the car round the corners yet, though I did go round a relatively sharp curve on the highway today roaring away in third gear... Big fat tires and stiff suspension certainly help, but it was stuck to the ground and felt quite stable. Felt damn good too :biggrin:

[Biggie™]

That way, it can be farther be tweaked by sprinkling some swaybars or extra strut bars.


Front strut tower bars do nothing for the Yaris. Look how close the top of the strut is to the firewall! They only add weight... The limited amount of body flex our very ridged cars do have wont be noticeable until you replace all the soft rubber bushing with race only metal bushings. The strut tower bar is just a favorite of the ricer crowd do to it's low cost and ease of installation, your suspension dollars will be better spent elsewhere on the NCP91 chassis.

Also, a swaybar is just a stretched out spring... Randomly adding more swaybar wont help much. You really need to plan out suspension modifications with a good solid goal in mind. If you want a sportier driving experience, upgrade to a performance suspension setup by HKS, Cuscu, Tein or TRD. The right spring/shock setup will more than likely solve any issues. Only after those are sorted out should you start thinking about loosening or tightening up the car with a swaybar.

Look at what TRD Japan offers for their spec Vitz/Yaris race cars... No swaybar. No strut tower bar. Only Bushings, Springs and Struts/shocks. I'm not saying swaybars are bad/useless, but they shouldn't be your first suspension modification.

[Russelt3hPirate]

Look at what TRD Japan offers for their spec Vitz/Yaris race cars... No swaybar. No strut tower bar. Only Bushings, Springs and Struts/shocks. I'm not saying swaybars are bad/useless, but they shouldn't be your first suspension modification.

sway bars are far from perfect as they are a band aid, designed to help super soft springs do a better job.

[graywolf_14]

Well sway bars are a tuning device. But anyways what would u guys compare the trd struts and springs to?

[ChinoCharles]

Not really sure what to compare them to... all I know is that there is absolutely no comparison between that suspension and the stock suspension. Way, way stiffer. Byebye ride quality, hello to staying flat in the turns. :thumbup:

[Tamago]

snap oversteer is your enemy

[03Z33]

I'm hosting a pre-order special for the new Progress Rear Sway Bar:

http://www.yarisworld.com/forums/showthread.php?p=47787#post47787

[Redbat01]

I bought my Yaris in September 2009. I installed a TRD rear anti-sway bar and it improved the handling significantly. Less understeer.