1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Chassis stiffening for 2011 Prius Five?

Discussion in 'Gen 3 Prius Accessories and Modifications' started by phntm_ai, Jun 9, 2019.

  1. phntm_ai

    phntm_ai New Member

    Joined:
    Jun 9, 2019
    11
    3
    0
    Location:
    Tustin, CA
    Vehicle:
    2011 Prius
    Model:
    Five
    Hey guys! I've been holding off the mod bug/itch since I got this car from my aunt 2 years ago,.... until now XD.

    I've been looking at the suspension upgrades, but not sure where I should start. Is there a consensus on what to go with and what order of importance? I don't care about aesthetics/looks of the bar(s)/brace(s) as long as the performance is solid. Been visiting this site on and off and it seems like most say to get the rear ARB first, but not sure if it's still the consensus (all the 2011 threads seem pretty dated) and not sure which bar(or kit) to go with. Please advise. Many thanks!

    Also, I remember seeing a post about swapping the undercover with one from another to have easier access for oil changes (no panel door thingy) or something to that effect; am I just remembering things or is that an actual thing?
     
    Burna J likes this.
  2. James Powers

    James Powers Senior Member

    Joined:
    Sep 11, 2017
    396
    555
    0
    Location:
    Bay Area
    Vehicle:
    2014 Prius
    Model:
    Two
    You will get a lot of different opinions on suspension mods but as you have read, the rear sway bar is the first one. TRD should meet your needs fine. Some dont like it due to attaching with end-links. Hotchkis makes one that mounts directly to the spring mount.

    As far as the rest of the chassis goes, I would suggest looking at Cusco. For suspension, you will need to know how low you want to go. Coilovers, AirRide, Lowering springs. Depending on how many miles are on your shocks, you will also want to consider upgrading those since adding lowering springs to an already used up shock, wont help much.

    But IMO, the rear sway bar is the best place to start.
     
    Montgomery and phntm_ai like this.
  3. phntm_ai

    phntm_ai New Member

    Joined:
    Jun 9, 2019
    11
    3
    0
    Location:
    Tustin, CA
    Vehicle:
    2011 Prius
    Model:
    Five
    Thanks for the info! What are the pro's/con's between end-links and direct mount?

    The car is stock so it's about 120k mi on shocks. I don't plan on lowering because I already get scraping in the front in a few instances (I'm currently trying to find replacement fasteners for the undercar shields because the front ones have disappeared... and the front bottom panel just don't know where to get them)
     
    #3 phntm_ai, Jun 10, 2019
    Last edited: Jun 10, 2019
    James Powers likes this.
  4. James Powers

    James Powers Senior Member

    Joined:
    Sep 11, 2017
    396
    555
    0
    Location:
    Bay Area
    Vehicle:
    2014 Prius
    Model:
    Two
    It has to do with how hard you drive. The end-links tend to snap under REALLY hard cornering or hard articulation from a crappy steep driveway when super lowered. But for normal back road or mountain driving they are good. The direct mount will have more benefit since it directly ties everything together. Although, there is a dude on here that autocrosses his Prius with the TRD bar and has no complaints or issues so far. Posts some solid times against some fast cars too!

    It sounds like the TRD one will be a good option for you. Easy to install as well. I have the TRD one and haven't had any issues and installed it in my driveway.

    You could also consider the TRD springs. They are categorized as "lowering springs" but they really don't lower the Prius much but will help stabilize the ride while still having the OEM comfort. Your old shocks will be fine to use with these as well. Never hurts to replace them at the same time tho..

    As for the under-body. There are a lot of guys that switched to the Lexus CT200H cover. I cant remember the post or the details.. Might be in the "what did you do to your prius today" thread.

    Once you start modding, it never ends.. HAHA :cool:
     
    Montgomery, phntm_ai and RMB like this.
  5. 04priusnow

    04priusnow Active Member

    Joined:
    Apr 30, 2013
    345
    200
    0
    Location:
    USA
    Vehicle:
    2010 Prius
    Model:
    II
    I got the hotchkis sway bars.. no endlinks. decent pricing and you can get both front and rear. Finally installed my front one

    Pixel 3a XL ?
     
    RMB and phntm_ai like this.
  6. phntm_ai

    phntm_ai New Member

    Joined:
    Jun 9, 2019
    11
    3
    0
    Location:
    Tustin, CA
    Vehicle:
    2011 Prius
    Model:
    Five
    Thanks for the replies! Where did you guys get your parts from?
     
  7. James Powers

    James Powers Senior Member

    Joined:
    Sep 11, 2017
    396
    555
    0
    Location:
    Bay Area
    Vehicle:
    2014 Prius
    Model:
    Two
    Lots of places to buy from.. Ive picked up almost all my parts for HybridPit.
     
    phntm_ai and Montgomery like this.
  8. 04priusnow

    04priusnow Active Member

    Joined:
    Apr 30, 2013
    345
    200
    0
    Location:
    USA
    Vehicle:
    2010 Prius
    Model:
    II
    Yep all my Cusco parts came from the pit.

    Pixel 3a XL ?
     
    James Powers and phntm_ai like this.
  9. phntm_ai

    phntm_ai New Member

    Joined:
    Jun 9, 2019
    11
    3
    0
    Location:
    Tustin, CA
    Vehicle:
    2011 Prius
    Model:
    Five
    Thanks for all the help, guys!!
     
  10. Kenny94945

    Kenny94945 Active Member

    Joined:
    Mar 24, 2016
    758
    387
    0
    Location:
    Sausalito
    Vehicle:
    2016 Prius v wagon
    Model:
    Four
    Chassis stiffening IMO is different than sway bars changes.
    Braces to tie the shock towers and under carriage to reduce frame flex is chassis stiffening.

    Yes, a rear sway bay can help reduce front end shock diving in a corner.
    I could agree to start there if I understand the OP's question.

    Oil change access panel.
    Could be the OP recollection is the failures/ breaking off of that drain plug access door.
    I'd leave the panel as it aids air flow under the car/ aerodynamics.
    I recall many have installed metal hinges to that access door or just removed it.

    Best of luck.
     
  11. phntm_ai

    phntm_ai New Member

    Joined:
    Jun 9, 2019
    11
    3
    0
    Location:
    Tustin, CA
    Vehicle:
    2011 Prius
    Model:
    Five
    So should I start with shock tower braces instead?

    Is the Lexus cover less aerodynamic?

    I was asking about chassis stiffening to improve handling because, at high speeds, the body (notably the rear) developed some shaking. I also wanted to improve control for lane changes and turns.
     
  12. Kenny94945

    Kenny94945 Active Member

    Joined:
    Mar 24, 2016
    758
    387
    0
    Location:
    Sausalito
    Vehicle:
    2016 Prius v wagon
    Model:
    Four
    High speed shaking.... 80 mph, 110 mph or higher speed?
    That implies to me wheel balance, maybe 4 wheel alignment.
    Also note a V is susceptible to cross winds.
    Also worth noting that maybe some bolt in the suspension or undercarriage is loose....get your torque wrench ready and inspect.

    In this case, I'd first balance (or confirm) all four wheels.
    Note: Find a shop with a Hunter Road Force balance which this tool is claimed to be the best tool to use.

    Then, yes, I would start with the undercarriage cross brace.
    I don't think the front shock tie bar brace will eliminate this issue....start with the center brace.
    I really say to do all three braces as the first step after confirming wheel balance.

    Then do your rear sway bar after the chassis ties are installed and tested.
    The rear sway bar may give you the corner entrance feel you desire.
    IMO the front & rear sway bars will not make a difference in a straight smooth line of travel.

    I am unsure about the Lexis part question you are asking.

    Good luck...fun project, yes!
     
    phntm_ai likes this.
  13. phntm_ai

    phntm_ai New Member

    Joined:
    Jun 9, 2019
    11
    3
    0
    Location:
    Tustin, CA
    Vehicle:
    2011 Prius
    Model:
    Five
    Thanks for the insight. I'll run it by my mech first to check the alignment and bolts and then run it to see. (probably wouldn't hurt to keep shopping around prices for the braces and bars in the mean time). This is the first time I did research for mods so I'm pretty new to figuring out how each mod affects performance/utility(if at all).

    It's the panel that covers under the engine (i think???).