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Best bang for the buck mods for improving high speed handling?

Discussion in 'Gen 2 Prius Accessories & Modifications' started by LVA, Aug 15, 2017.

  1. LVA

    LVA Junior Member

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    Hi mates!

    I have owned my Prius one year or so, and i'm quite happy with it. It is cheap to run and it is actually very good car to drive in gravel and snow. However, it does get little bit of unstable at higher speed, ie 70mph or so. My car is high mileage 2006 "Touring" and suspension components has been changed few years ago and they are fine i think.

    This is our 3rd car so i don't have that much money for these mods. So, what mods at the moment gives you the best bang for bucks to improve high speed handling? :)
     
  2. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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  3. Lucifer

    Lucifer Senior Member

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    The front upper strut bar did the most for my 06'
    2nd was the underbody mid section stiffening plate
    3rd was the 17" 45 series tires and wheels
     
  4. 69shovlhed

    69shovlhed Surly tree hugger

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    1. wider, better tires, 2. aftermarket corolla/matrix Progressive rear sway bar (or TRD), 3. front oem corolla sway bar. the sway bars make a tremendous difference on non-touring models; I expect they will help the touring too. a used front sway bar is cheap, but installation requires the engine cradle to be unbolted from the body, or the steering rack to be removed. its not a bad job if you know how to work on cars. rear sway bar is very easy to replace.
     
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  5. LVA

    LVA Junior Member

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    I'm not sure about sway bars at the moment, because my car goes around corners reasonable well and body roll is not that much a problem. I'm sure they DO improve the handling for sure, but i will make those modifications later.

    What is the biggest reason for unstable high speed handling? Is it flexy chassis/body? Lucifer and Jimbo could be right. Next question is where i can buy those parts? I live in Europe and most of the ebay sellers postage fees are ridiculous.
     
  6. 69shovlhed

    69shovlhed Surly tree hugger

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    what kind of tires do you have? when was the last time it had an alignment? over here Toyota put GY integrity tires on them and they are terrible. crap tires, out of alignment, body flex, weak suspension all contribute to lousy high speed handling. front strut tower brace will probably help, but they are kind of expensive, and the cheaper ones look so flimsy I doubt they do much.
     
  7. SFO

    SFO Senior Member

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  8. Kevin_Denver

    Kevin_Denver Active Member

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    These are the best recommendations. Completely agree.

    The biggest factor in the handling of the car is the tires' ability to make friction with the road. This is why the first upgrade is almost always tires. If you want better handling, go for a slightly wider (eg. 205/60R15) ultra high performance summer tire (easy reference is to use Tirerack.com and compare tires' ratings). Follow this with upgrading the sway bars.

    Stability on uneven surfaces is mostly affected by the suspension. Worn out struts can cause excessive bouncing. With tuning the car for a race track or otherwise, too high of a spring rate won't keep the tires on the road well and grip will be reduced on uneven surfaces. Too low of a spring rate and the car's weight will shift too much in corners, causing slip on the outside tires and reducing maximum cornering speed. A balance for the conditions must be found for the car.

    Also, a car in over-steer feels "unstable" to the average person. Research oversteer and understeer and their causes if you aren't already familiar.
     
  9. LVA

    LVA Junior Member

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    I have a two sets of tires. Winter tires are Bridgestone blizzaks and summer tires are Nokia Hakka Green. Both are premium brands and OK'ish tires. Standard Touring tire sizes. Suspension should be good, but i haven't check alingment in a while. So that's a good place to start! What is good air pressure for tires in Prius?

    I don't know, but thanks for posting. Need to check it out. Usually cheap parts are bad tho :D

    Problem for me is that it isn't stabile when you drive in highway with high speed. Front end does wander from side to side. Surface is usually as good as it gets. In bad roads my car is good to drive, ie snow and gravel and so on. I'm not sure about sway bars at the moment. They do improve handling when cornering, but i'm fine with that now.

    I own a mkIV Supra and i have modified it a little bit. The thing is, i always want to be a sure that i make the right mods so i don't fucked up the car. Prius is soooo different car with different problems so i need to think about it little bit. It feels that flexy body in Prius is my biggest problem.

    So:
    - Chechk the alignment (should be good tho, it goes straight when the speed is below 60mph)
    - Proper tire pressure (?)
    - Stiffen the body: stiffer mid plate and front strut brace
    -???

    What do you guys think about it?
     
  10. 69shovlhed

    69shovlhed Surly tree hugger

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    the mounting brackets look kinda flimsy to me. they might be 1/4" thick high carbon steel, but for that price I doubt it. I have this one, which I got in trade for some diagnostic work for a priuschat member, so I don't know the brand, but the mounting brackets are very stout.
     

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  11. 69shovlhed

    69shovlhed Surly tree hugger

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    wandering could be incorrect toe-in adjustment; also snow tires aren't known for good dry handling. I don't know anything about nokia tires.
    I set my tires at 40psi and never noticed a problem with wandering. I would want to inspect the suspension for anything worn and get the alignment checked first. then look into a quality strut tower brace.
     
  12. SFO

    SFO Senior Member

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    Almost looks like a BT brace, except for the green brackets.

    Do those brackets go full circle on top of the strut?

    How is the access to the fluids and relays?
     
  13. LVA

    LVA Junior Member

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    Well, it could be just me. Car is good for about 65mph, above that there is a little bit of wandering, steering feel is not good and it is not that stable anymore. I put 40 PSI for tires and it is a little bit better to drive now. I will check alignments and get some braces. In higher speeds there is a little bit of clonking noise from the rear hatch ie it feels that body does flex. Anyway, i will report back after i can get some parts installed.
     
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  14. 69shovlhed

    69shovlhed Surly tree hugger

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    its raining now, or I'd go check to see, I think there are some rubber stops to keep the hatch from clunking. as much as I like these cars, they are kinda flimsy, so upgrading and adding braces is definitely a good idea.
     
  15. LVA

    LVA Junior Member

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    So, the question is which one offer more bang for buck:

    Tanabe 2 point Sustec front under brace
    http://www.andysautosport.com/products/tanabe_racing_development__TUB151F.html

    OR

    Tanabe Sustec Front Strut tower bar?
    http://www.andysautosport.com/products/tanabe_racing_development__TTB151F.html

    :)
     
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  16. 69shovlhed

    69shovlhed Surly tree hugger

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    I would go for the strut tower bar, because I suspect the strut towers are more likely to flex than the undercarriage, which already has a big steel subframe bolted to it.
     
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  17. tazman

    tazman Junior Member

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    I see you guys talking about the Corolla rear sway bar. Is there a specific year I should look for and can I use the front and rear bars from the same car?
     
  18. Kevin_Denver

    Kevin_Denver Active Member

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    Search the forums for exact years, but you'll want the front bar from a junkyard Corolla/Matrix. The rear sway bar on these cars is only slightly thicker than the stock Prius rear sway bar, so you'll want a 22-26mm rear aftermarket sway bar instead. Progress and TRD are popular models.
     
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  19. 69shovlhed

    69shovlhed Surly tree hugger

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    03- 08 definitely fit, but I think in fact the corolla bars are the same up to like '15. I got my front bar from ebay for $45. make sure you get the frame bushings and clamps with the bar too.
     
  20. tazman

    tazman Junior Member

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    Thanks, that's exactly the info I was looking for.