How to fix my Vibe's understeer?

[bellwilliam]

Being a family car, I guess Toyota dialed a lot of understeer into the Vibe. I really prefer a more natural handling car. any of you feel the excessive understeer? and how should I fix it.1. I see quite a few post about installing Progressive rear sway bar. I am sure this would fix some of the understeer. so I wonder if anyone had experience with installing rear sway bar ONLY. I am not interested in front sway bar as it would dial in more understeer. 2. is Progressive rear bar adjustable? if not, does anyone of any other brand?3. I have already lowered my rear tire air pressure by 5 pounds. 36f, 31r, but still with significat understeer. do anyone have any recommendations? I do drive the car hard around corners.4. I did install front TRD strut bar, which stiffens up the front end, does the strut bar adds to my understeer?thanksbellwilliam

[cohocarl]

quote:1. I see quite a few post about installing Progressive rear sway bar. I am sure this would fix some of the understeer. so I wonder if anyone had experience with installing rear sway bar ONLY. I am not interested in front sway bar as it would dial in more understeer.I had a Progress rear bar only on mine. Yes, I'd say it reduces the understeer, and "tightens up" the steering response. For around town driving it is seems fine, but at high speeds, it seemed to make it a little "twitchy" if you know what I mean. quote:2. is Progressive rear bar adjustable? if not, does anyone of any other brand?No, and I am not aware of any that are adj. for the Vibe/Matrix. I'm not real familiar with this type of "twist beam" suspension on the rear, but I don't know how a rear bar could be made to be adjustable with this type of suspension.Carl

[bellwilliam]

with "twitchy"', I think you meant oversteer. that is not a good thing at high speed. may be adding a rear bar only corrects too much of understeer. But that sounded great for low speed driving.another question: does base and GT have same sway bar setups?

[cohocarl]

quote:does base and GT have same sway bar setups?From what I have read, they are the same, but I could be wrong.

[NovaResource]

quote:Being a family car, I guess Toyota dialed a lot of understeer into the Vibe. I really prefer a more natural handling car. any of you feel the excessive understeer? and how should I fix it.Yes, engineers make cars understeer to protect the drivers, however, understeer is part of FWD by design. It's very hard to get a FWD car to have oversteer. Basically, a FWD under power will understeer. Under braking it will bite more creating less understeer but not eliminating it.

[bellwilliam]

I was hoping to lessen the understeering effects of the car, I actually prefer a little bit of understeer for high speed driving. I just think my Vibe understeer a lot more than my other fwd cars.In a more natural handling car (fwd included), it is easy to induce oversteer (for tail to come inline) by lifting throttle. My vibe is impossible to induce oversteer. I was wondering if my front TRD strut bar actually made it understeer more than a stock Vibe.

[rasermon]

I don't see a problem with understeer with my GT, but what I do notice is torque steer. Torque steer is common in front wheel drive cars because reaction forces created in the half-shafts can generate uneven steering forces in the front tires.One other thing I notice is the changes in the direction of the wheel that happens without my steering input. I think it's called toe steer. This happens to me on small uneven surfaces on the road. Is this common with front wheel drive cars?

[NovaResource]

quote:I don't see a problem with understeer with my GT, but what I do notice is torque steer. Torque steer is common in front wheel drive cars because reaction forces created in the half-shafts can generate uneven steering forces in the front tires.Yes, this is also a very common FWD problem.quote:One other thing I notice is the changes in the direction of the wheel that happens without my steering input. I think it's called toe steer. This happens to me on small uneven surfaces on the road. Is this common with front wheel drive cars?It's called bump steer and it's steering angle change as the wheel travels through it's up and down motion. This is a problem with any vehicle, not just FWD. It has to do with the length difference of the control arms and the tie rods. The greater the difference in length between the two, the greater the bump steer.

[rasermon]

Thanks Scott, your a scholar and a gentleman.The bump steer seems more noticeable with my vibe over any other vehicle that I owned. It's no big deal for me, just wasn't sure what it was called.

[shibaman]

Talk to JC at Hotchkiss tuning. He has good info on their products. i have their sway bars on my Vibe and I am very happy with them. It compleatly transformed how the car drives!

[Hawke]

quote:One other thing I notice is the changes in the direction of the wheel that happens without my steering input. I think it's called toe steer. This happens to me on small uneven surfaces on the road. Is this common with front wheel drive cars?There is also a relationship to toe setting as well. If the car is toed out it has a tendency to follow ruts and grooves in the road. This is a reason why most cars are toed in. Tire selection also has a big difference in following ruts and grooves.

[NovaResource]

quote:There is also a relationship to toe setting as well. If the car is toed out it has a tendency to follow ruts and grooves in the road. This is a reason why most cars are toed in.Actually, most RWD car are toed in because as the car travels down the road, the car is pushing the front wheels and that it forces the wheels even.Most FWD cars are toed out because the front wheels pull the car and under power, the wheels pull themselves even.

[Lorin]

Shibaman - talk to me! I'm trying to justify in my mind spending 300 smackers ( or "3 bills" like they say in supr-2nr tv) for the hotchkis sway bars....Is there any tradeoff? rougher ride? Any disadvantages?

[bellwilliam]

so here is my next question, where can I get the rear sway bar cheap

[cohocarl]

quote:so here is my next question, where can I get the rear sway bar cheapI had my old Progress rear bar that I took off, but a member of Matrixowners.com i.m.'d me an offer and it's gone.Mine was about $120 shipped which isn't too bad, from this place: http://www.optauto.com/webstore/

[Hawke]

quote:Most FWD cars are toed out because the front wheels pull the car and under power, the wheels pull themselves even.I can't say that I agree with you Scott. I agree with the FWD vs RWD statement but not the toe settings. Here are some Pontiac total toe targets:Vibe: 0.00Grand Am: +0.10Bonneville: +0.20Grand Prix: +0.06Sunfire: 0.00None are toed out. The suspension geometry and travel as well as desired driving characteristics play into the toe setting as well.

[NovaResource]

True. I should have been more clear in my statement. I should have said "toed in less" instead of "toed out". FWD will have less toe-in compared to RWD cars.Sorry for the confusion.

[shibaman]

Lorin, with the Hotchkiss bars the ride is better because you don't have that rolling back and forth all the time. Cross winds and passing trucks make little movement. It has made my base Vibe with the 16" tires tossable. well worth the $. It is expensive to get the front installed. It may cost the same to have it done with the TRD bars. I think that they are not as stiff. I believe that you would have better handling with the Hotchkiss bars.

[Lorin]

I can't seem to get off the fence on this one....I'm doing a roadtrip to to Indiana tomorrow, so I'll have plenty of time to decide. Although the 'sale' will be officically over in a few hours of this posting, I have a feeling the prices are only going to improve. Plus, I'm going to survey the "lay of the land" at this customer and decide how much more work (and roadtrips) I'll be doing this summer. Theory: All these parts first come out at full retail price, then they go "on sale", then the price drops to under the sale price, then they go "on sale" again. With TRD swaybars readily available at $300 on the web, I think Hotckis may come down a little more. So far, this has seemed to be the pattern with everything I buy "on sale".

[shibaman]

Try monkey wrench racing. They list the Hotchkiss bars for $269. Some times you get what you pay for.