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Need to improve cornering ability...

Discussion in 'Gen 2 Prius Accessories & Modifications' started by LDPosse, May 25, 2014.

  1. LDPosse

    LDPosse Member

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    A few months ago, I moved in with my fiance'. Everything has been great, except that my Prius's handling has been a bit lackluster on the new commute.

    Background :
    Although my drive isn't quite as severe as riding "The Tail of the Dragon", it is riddled with sharp, hairpin curves, lots of elevation changes, off-camber sweepers, etc. Right now, the car has 140k miles on it, and the suspension components are all bone-stock. Springs/Struts, bushings, etc are all factory original components. I am running stock size Conti Pro Contact tires on the factory 15" wheels. Compared to the original Integritys, these tires seem to handle better, but the treadwear is awful. I'm currently on my 2nd set of them, at 4/32" tread left and only 20k miles on them. :mad: I have also noticed that the rear of the car has been increasingly unstable when traversing mid-corner bumps. This is particularly unsettling on the local stretch of I-81. The highway is in a severe state of disrepair, and hitting all of these mid corner bumps makes the back of the car feel like its dancing over the highway. In comparison, I can take the same stretch of road in my '71 Buick Skylark (solid rear axle but new suspension components) without skipping a beat.

    The following 2 links are about Gold Mine Road, which is the twistiest part of the commute. These will give an idea of the drive. These links do not belong to me, btw.

    Video : http://youtu.be/j4KSMCeBprY

    Map / Elevation chart : Gold Mine Mountain - A bike ride in Tower City, PA

    What I'm looking for :
    Most important, I want to get my 140k mile suspension back into shape. I figure this will mean new struts, and possibly springs. I'm not sure what the best option is here, whether it be factory Toyota parts, or aftermarket. I did some quick searches online, and it seems that most performance suspension places don't even list Prius parts.

    Improve the car's cornering ability... I figured that my best bets here were upgraded sway bars, and possibly looking for larger wheels. I thought about trying to find a set of 16" touring wheels, or maybe a set of Scion TC wheels. I just don't want to ruin my MPG. I've thought about keeping the 15"s and putting winter tires on, since the winter commute is pretty slow regardless of the weather. PennDOT dumps copious amounts of salt and anti-skid material as soon as the first snowflake of the season is forecast.

    Sorry for the verbosity.... I just want to be well informed before I pull the trigger on making these kind of purchases!

    Thanks!
     
    #1 LDPosse, May 25, 2014
  2. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    #2 JimboPalmer, May 25, 2014
  3. 69shovlhed

    69shovlhed Surly tree hugger

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    I run 205/60r 15 tires, and I've replaced both sway bars. rear is Progressive from TH motorsports; its for corolla/matrix actually. front is corolla from a junk yard. the stiffer bars and wider tires make a tremendous difference. a set of new struts would definitely improve the ride quality too. springs most likely don't need to be replaced unless you want some stiffer aftermarket stuff ($$), but I don't care for the harsher ride. seems like oe or any name brand struts would be fine.
     
    #3 69shovlhed, May 25, 2014
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  4. Justdidit

    Justdidit LVNPZEV

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    Just to be clear...You want to improve the handling and so far you have only changed the tires?

    Have you looked into the just replacing the rear struts but also adding the larger front and rear sway bar?

    At most maybe additionally adding some stiffer after market springs, ones that don't necessarily lower the center of gravity...although that WOULD help also...
     
    #4 Justdidit, May 26, 2014
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  5. LDPosse

    LDPosse Member

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    I have done *nothing* to improve handling so far. I just got a different brand replacement LRR tires for the car when my last set of OEM integritys wore out. I like the Conti Pro Contacts in dry and rain, but they are not very good in the snow, and the treadwear is lousy. Got 21k out of the first set, am at 23k on this set and they are nearly to the treadwear indicators. Camber, Caster, and Toe are all in spec. Car drives straight as an arrow, and all 4 tires are worn evenly. Rotated every 5000-6000 miles.


    I thought about new springs because the Prius seems to sag a bit in the back, it would be nice if it sat a little more level.....
     
    #5 LDPosse, Jun 3, 2014
  6. LDPosse

    LDPosse Member

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    Did you need to have the speedometer calibration adjusted for these tires? Did you have a noticable loss in MPG?
     
    #6 LDPosse, Jun 3, 2014
  7. 69shovlhed

    69shovlhed Surly tree hugger

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    actually, the speedo is more accurate with slightly bigger tires. speedo reads a little high with 185's. not sure about mpg; I was getting about 52 when I had a highway commute with the 205's. seems to me it was about the same with the lousy integritys. if you go with lrr tires, it shouldn't lose much if any mpg.
     
    #7 69shovlhed, Jun 3, 2014
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  8. Daves09prius

    Daves09prius Active Member

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    To improve handling I'd do: G7 chassis plate, tannabe front under-brace, strut tower brace. Progress rear sway bar, 2006 matrix front sway bar, 205/60/r15 General Altimax HP tires, new struts and H&R springs.
     
    #8 Daves09prius, Jun 9, 2014
    psymon100, xpcman and Justdidit like this.
  9. Justdidit

    Justdidit LVNPZEV

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    Pretty sure from what I've found, you cannot do any Speedometer calibration on the G2 Prius. Also apparently this is acceptable range to Toyota...

    Reference: mph (U.S.A)
    Standard indication Acceptable range
    20 mph 18.0 to 22.0 mph
    40 mph 38.0 to 42.0 mph
    60 mph 59.0 to 63.0 mph
    80 mph 79.0 to 83.0 mph
    100 mph 99.0 to 104.0 mph
    120 mph 119.0 to 125.0 mph
     
    #9 Justdidit, Jun 12, 2014
  10. JimN

    JimN Let the games begin!

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    Pretty country--and the joy of a full battery.

    There's going to be a FE hit going from a LRR tire to a performance tire. Increasing the wheel size is also going to cause a hit.

    I presume your tp is much higher than recommended.

    My replacement tires, Yokohama AVID ENVigor make me happy one weekend a year when I rally & autocross around State College. I can definitely hold a higher speed down the mountain compared to the OEM tires which does boost the FE.
     
    #10 JimN, Jun 13, 2014
  11. Daves09prius

    Daves09prius Active Member

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    JimN you use to drive an EV-1?! That's so awesome! How did you like it? I think it's such a shame that GM crushed them!
     
    #11 Daves09prius, Jun 13, 2014
  12. JimN

    JimN Let the games begin!

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    Dave, I haven't even gotten close to an EV-1. I reference those two cars to illustrate what was accomplished 15 years ago and a rebuttal to all the manufacturers that say, "we can't do that because the battery technology doesn't exist"...or some other nonsense.
     
    #12 JimN, Jun 14, 2014
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  13. ZiggyM

    ZiggyM Junior Member

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    I don't want to hijack the thread but it seems relative to the OP's handling issue.
    Justdidit, what size tire-wheel combo do you have on that photo of your Prius?
    Any FE hit on FE? Any boost in handling with the larger wheel/tire?
     
    #13 ZiggyM, Jun 18, 2014
  14. Justdidit

    Justdidit LVNPZEV

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    All my mods are listed in my signature. 19x7.5 Wheels & 215/35ZR19 tires - These wheels are awfully heavy and kill my FE but I'm still in the +40mpg AND with the OEM wheel/tire combo I was in the +50mpg after all my intake/exhaust mods.

    Anytime you increase the rotational weight, your bound to take a hit on FE. However, this being said, there are plenty of wheel/Tire combo's out there that will weigh less than OEM setup allowing you to maintain OEM FE or better.

    Most anytime you increase surface area of contact AND reduce sidewall height, handling will improve. My Prius def no longer handles like a typical Prius...but mine is also not your typical Prius.
     
    #14 Justdidit, Jun 18, 2014
  15. Daves09prius

    Daves09prius Active Member

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    And the Prius modder community is all the better for it! You've given me so much to aspire for...
     
    #15 Daves09prius, Jun 18, 2014
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