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Question about front & rear sway bar changes.

Discussion in 'Gen 2 Prius Accessories & Modifications' started by pumpanddump, Jul 30, 2018.

  1. pumpanddump

    pumpanddump Junior Member

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    I understand that the best / simple mods for performance in the prius are better sway bars and wider tires. People on here have said I can expect a dramatic improvement in handling via a used front corolla/matrix sway bar and progress rear sway bar from TH motorsports as a common upgrade.

    I have a 2004 prius, I had new struts installed about a month ago, the sway bars and the rear suspension were inspected by the mechanic and I was told that everything appears sound - just some smaller parts were replaced - sway bar arms, I believe. However, before and even after this strut job was completed.. I still feel headaches and a bit dizzy after driving.

    I had another mechanic inspect the suspension recently, and same thing - he doesn't see anything wrong. He said "some people just cant drive hatchbacks." The issue I am having with the Prius is that to ME it feels like the rear of the car is separate and wiggling around and I am feeling every bump. To everyone else the car drives fine, including my wife - who doesn't feel sick after driving the car.

    Can I expect any improvement in my situation via the expected dramatic improvement in handling via a used front corolla/matrix bar and progress rear bar upgrade?
    Thanks in advance.
     
  2. davecook89t

    davecook89t Senior Member

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    If the rear of the car really is wiggling around, I would think that you would need to make frequent steering corrections to keep the car going straight down the road. Do you find that to be the case? If so, there may be a real problem with the car's suspension that hasn't yet been identified.
     
  3. pumpanddump

    pumpanddump Junior Member

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    Hi davecook89t, No I dont need to make allot of steering correction. Just a little correction while on highway, but its not much of a fight.
    In fact I got a wheel alignment at the same time the front struts were put in.

    Its been now about a two + months since that repair.
    I dont drive the prius that often because of the dizzy feeling afterwards.

    With the second mechanic, we even drove down the road together... he couldn't feel it... but I sure could - on a simple up and down a road for about 2 miles. Thats when he said "some people cant drive hatchbacks." My other car is a Acura TL and I drive that all day for hours - zero problems, I never feel dizzy or headache. My wife drives the prius more than I do and she has zero issues with the car, feels fine.
    So I am at a loss for a solution, plus I really WANT to drive the Prius.
    Do you think the sway bar changes will assist me?
     
  4. davecook89t

    davecook89t Senior Member

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    Hmm, if the problem is really only one of your own perception of the car not being stable, I'm not sure sway bar changes would help, although I'm not qualified to offer a professional mechanic's opinion. I guess if you could convince yourself it was better (placebo effect), they would help.;)
     
  5. pumpanddump

    pumpanddump Junior Member

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    You are right, in that I am not sure there will be a positive outcome from this pursuit. But, if its a fairly cheap mod of corolla used parts and one new part that helps the car I am interested regardless.
    It's not like I am asking if I should install a airbag $u$pen$ion $y$tem instead - you know, fix it with a sledgehammer mod, LOL.
     
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  6. SFO

    SFO Senior Member

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    Strange that you mention the rear end moving around and feeling more bumpiness coming from the rear, I have that same feeling when driving the GFs Honda Civic, it never use to do that even after putting on new struts and shocks all around, then a couple of years ago things changed one day and now it feels like the rear wants to hop around on its own.

    Back to Prius : I notice a steering wandering issue at freeway speeds quite often, and will look around at the flora and fauna for potential wind which might be causing such.. then realize there is little wind.

    The gen2 is notorious for wandering, or so I believe. One of these days (hopefully not soon) I will ask an officer what they think.

    Right after purchasing this Prius I installed a used solid core rear sway bar ($25) hoping it would make a difference in the wandering, it may have, though I'm not really sure. I still think installing a front solid core bar could help ( @DivideByZer0 are you out there :whistle:).

    Solid core sway bars (Toyota or aftermarket) may or not make a noticeable difference to you, but moving up to a wider/lower profile tire possibly could if you're currently rolling on the 185/65/15's.

    I recently downgraded from a 'Touring' tire/wheel size of 195/55/16 to the 'Non Touring' base tire/wheel size of 185/65/15.. and made a big mistake in going with narrower/taller tires (like all the other gen2). If I could do it over, I would've put 195/60/15 or 205/60/15, if not a 215/55/15 on all four corners (or insert any shorter/wider tire that a tire shop will mount, call around first as not all will) :cool:

    Now this Prius wanders around even more than I remember, of course I'm still hoping its just the new tread depth (12/32) wiggling around on these grooved roads. Don't know if my excessive wandering was from going narrower, taller, or both :confused:

    Now I have a front strut tower brace that I've been meaning to install, and if that fixes my "faux drunk driving" I will be impressed. Otherwise I am stuck with these "new tires" until I replace them with something shorter/wider.

    Remember not all aftermarket sway bars are solid core, do the math before committing.

    Somewhere on here I read about replacing worn out 'end links', 'tie rods', or "something else on the front end" which made the gen2 handle 'like new' again. Seemed fairly convincing, but can't find that post via search :(

    Here is a link to help with tire sizing : Rim & Tire Size Calculator. Custom Offsets - Wheel-Size.com
     
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  7. 69shovlhed

    69shovlhed Surly tree hugger

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    there are undercarriage braces from japan that should tie the car together better; justdidit had some for sale after his got totaled. the sway bar upgrade reduces body roll, but that might not help with motion sickness. it likely does stiffen up the rear axle beam, because the rear bar bolts inside of it, and that might help some. I would go ahead and get the rear bar and try it out. very easy install. you should also get trd or some type of better hardware with heavy washers too; the oem bolts are really too small. someone took a picture of the trd bolts and the heads and nuts were definitely larger. I used Benz S500 control arm bolts, but you have to cut them shorter.
     
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  8. pumpanddump

    pumpanddump Junior Member

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    Thanks for your informative post, I searched ebay and even via google... I cant find a stiffening brace, chassis brace or anything of the kind on ebay. Im not sure if a junkyard would have this since its a modification piece.. its probably not in their computer system, right?
     
  9. pumpanddump

    pumpanddump Junior Member

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    I do not know.. if I am posting a f'n mess or what... but I tried to say thanks to 69shovlhed by quoting your post... but this f'n chromebook turd lost the quote or triple posted it.
     
  10. 69shovlhed

    69shovlhed Surly tree hugger

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    $#!+ happens. the braces are only sold in japan as near as I can tell. somewhere you might find a link to the site, but unless you can read Japanese, gonna be difficult to figure it out. search justdidit's posts. there should be a link in his thread; also there was a guy in hong kong with a heavily modded gen 2.
     
  11. egg_salad

    egg_salad Active Member

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    Sigma Automotive will import you all the chassis braces you want, and their site is in English!
     
  12. Lucifer

    Lucifer Senior Member

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    You want the front upper strut bar, the body stiffeners and a thicker rear lower bar.

    Clear your history and try searching again.
     
  13. dorihachigo

    dorihachigo Junior Member

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    It may be very well the case that a stiffer rear sway is detrimental for the Prius. The sway bar ties up the opposite wheels to prevent the car from 'swaying' around the corner.

    However, with the Prius uber soft spring rate, when with side of the wheel experiences a bump or a jolt, the stiffer sway bar easily communicates it to the opposite wheel.

    I was also thinking of wider tire tramlining the road but even plus size wheels on a Prius isn't wide enough to experience tramlining.
     
  14. 69shovlhed

    69shovlhed Surly tree hugger

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    nope. thicker rear bar works great. you haven't tried it or you'd be wishing you installed it the day you brought the car home. But, if you drive aggressively, it will oversteer unless you add the front too. the front corolla/matrix bar balanced it out nicely; with just the rear it felt like it wanted to fishtail if I took a corner too fast. body roll definitely reduced even with just the rear bar.
     
  15. Kevin_Denver

    Kevin_Denver Active Member

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    What tires do you currently have on the car and what pressures front and rear?

    Completely different car, but I had some problems on my Porsche with with oversteer due to having different tires on the front and rear from the previous owner. Running 5 psi more on the rear tires corrected the problem and the car is now slightly understeery, which is perfect for street use. You might try running 5 psi more on the rears than the fronts and see how the car feels (like 35 front, 40 rear). Increasing rear tire pressure reduces the tendency of a car to oversteer.

    Also the bushings on older cars can get soft/spongy/worn, which can allow wheels to toe out slightly under cornering/movement which gives an uncontrolled kind of feel. If you have it from the alignment shop, I'd check what toe settings they have on the car versus factory spec'd. On most cars it's with a slight toe in front and rear for stability. To get the same stability feel on an older car, even more toe in is needed due to the worn bushings.

    Also, some people on these forums swear by a front strut tower brace for stability.