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Anyone Researched Suspensions for Better than Stock *Ride Comfort*?

Discussion in 'Gen 3 Prius Accessories and Modifications' started by acceleraptor, Feb 18, 2022.

  1. acceleraptor

    acceleraptor Member

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    2014 Prius Plug-in
    Model:
    Plug-in Base
    I'm approaching 120k and just a few days ago completed cleaning out my throttle body, intake manifold, and EGR valve+cooler assembly, + replaced my PCV valve (might as well while I was down there), all those gaskets, and the spark plugs. Changed coolant + oil, of course, and inv coolant + trans fluid are probably next, just to get all that stuff rounded out.

    But I'm also still on the stock suspension. For the past maybe 5-10k, my RR corner shudders and gives a slight clunking sound going over even fairly minor road imperfections. While doing all the above, I checked down below and noticed it looks like this:
    View attachment 222859

    and this:
    View attachment 222861
    That bottom is glistening with fluid clearly leaking slowly.

    By comparison, the RL (driver) side looks dry:
    View attachment 222860

    With the front strut assemblies, the insulators (accordion rubber) looks dried out and falling apart to pieces: View attachment 222862
    but, from my ignorant just-a-glance inspection, I don't see anything visibly wrong with anything underneath those, and driving-wise they feel "serviceable" though for who knows how much longer. So I'm looking at replacing the old shocks for the rear at the least. And am researching what options there are for that and maybe the front depending.

    Obviously, the simple option is the stock shocks + struts, which I believe would be KYB Excel-G (and Strut-Plus if go fronts too), and I'll probably look at this as the baseline option. But even back when this car was new, my mom was never that impressed with the ride comfort.

    Now, I *do* drive slightly more aggressively than the average driver probably does (which didn't help passenger comfort), mainly just to pass painfully slower or distracted/hazardous drivers, but I'm also no street racer nor do I pretend to be, and use this as not only our daily driver, mostly for carrying passengers (family) or for carrying light to moderate loads, and just making long commutes for day trips around the Bay. I actually like the stock riding height, don't care for the look of lowered cars, and, if anything, would like to be able to raise the height (dynamically, if possible) since I creep on and off my driveway and still easily brush the bottom plastic engine covers on the sidewalks.

    Also, the freeways and even public roads here in the Bay Area are getting rougher. They're increasingly full of potholes, trash, debris from wrecks and/or people illegally dumping on the sides and it blowing/tumbling out into the lanes (or possibly just chucking stuff out the windows or falling off the backs of vehicles, not very clear), and there seems to be less road maintenance.

    I know there're air suspensions mainly for either performance/sport driving as well as the one used by the OffRoad along with their lift kit, which seems more like the ones used mainly by trucks/suvs for hauling, but I've only been able to find air suspension for improving ride comfort as options or standard on luxury cars. So I'm wondering if either there are any that are aftermarket, and if anyone here has experience with them, or if any of these ones made for performance can be configured mainly for comfort *without* lowering the car.
     
  2. black_jmyntrn

    black_jmyntrn Senior Member

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    acceleraptor likes this.
  3. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    It's not easy to improve the ride comfort of a given vehicle through suspension work alone, but here are a few things you might try:

    • Fix existing defects and remember that old dried-out tires ride hard and loud <--- can't stress it enough
    • Lighter wheels and tires to improve the ratio of sprung to unsprung weight. Can expose you to more frequent wheel breakage though.
    • higher profile tires can absorb more shocks but they'll also rob some fuel efficiency, not always kind to handling

    "bagging" a car is expensive and difficult as you need to include and maintain an air compressor and plumbing. Both are a bit noisy in the cabin. It can help with the ride, but it tends to help heavier cars more than lighter cars. More people do it for the appearance results of dramatic height changes than comfort, so that should tell you something. None of that means it wouldn't help, it's just a lot of work and expense for not a lot of results.

    Where luxury cars gain serious comfort vs. something like a Prius is in the measurements. Many of the most comfortable cars have very long wheelbases and a significant amount of mass in the cabin area. Both of these factors add stability and allow for generous sprung/unsprung ratios. When you hear of luxury cars with "air suspension" you are usually hearing about Nivomats, which are more about controlling ride height across a wide payload range rather than improving comfort.

    In your shoes I would take this in two phases:

    First, inventory the shocks, end links, bushings and wheel bearings. Renew any found lacking. I'm a KYB fan, they are great parts for these cars. Then get it aligned. Don't be hesitant about repeating the alignment check and adjustment, not all technicians do it as well. Some shops still sell all-you-can eat style lifetime alignments and it's worth that for a project like this.

    Second, try to install the smallest AND lightest wheels that physically fit over your existing brakes along with slightly higher profile tires. I have not tried this project on your model of the Prius so it is on you to make sure it fits, but I would probably start by looking at Konig Helium or Enkei RPF1 wheels in the 14x7 size with 185/75R14 tires. You need to preserve the stock outer diameter to maintain existing acceleration, braking and efficiency, but the higher profile tires and lighter wheels would soak up more of the hits. Be picky about your next set of tires, even if you get the stock size on your existing wheels. Be aware that you can choose comfort, though it usually comes at the expense of other desirable qualities.

    Good luck!
     
    #3 Leadfoot J. McCoalroller, Feb 18, 2022
    Last edited: Feb 18, 2022
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  4. acceleraptor

    acceleraptor Member

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    Yeah, got the impression this might be case, but thought it'd be worth consulting people with more experience having actually done it.

    So higher sprung, lower *un*sprung => higher stability, etc.?

    I'll check those out as it's a name I hadn't come across yet, and I wouldn't be averse to being able to handle a heavier loads.

    Next time I'm down there, gonna prod an' check the bushings and other rubber to see as to their condition + the other elements in general. Bought some 2 years worth of unlimited alignments from the dealership, which I used after each 5k service appt, but lotta times the car seemed to wanna veer slightly to the right when let go and immediately after they'd done these "alignment" jobs, then after they scratched my windshield tint while replacing those service reminder stickers and refused to cop to it, I kinda just stopped going there for the rest of the service contract period and switched dealerships. Now that contract ended way back at 80k and I'm into the time where I'll just do my own oil changes an' such. Guess I'll look around again. Didn't seem like a bad deal overall, just got the sense they did as little to honor it as possible + that other issue.

    Yeah, I'll probably still keep maintaining around 50mpg or higher as the top priority, and "ride comfort beyond stock" as 2nd or 3rd. Might just be a case where all these other options just aren't enough bang/buck over the simple cost of the OEM. This is mainly for my knowledge in finding out what's available out there, and for my mom, who loves to go on about how my uncle drove way "more smoothly than I do" (no kidding, mom—he drove those older expensive Mercedes and a lot slower than I do.. XD).
     
  5. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    I think I expressed it incorrectly in my post, sorry to have created confusion. Essentially you want the heaviest possible cabin and chassis with the lightest possible wheels/tires/brakes. The idea is that if you hit bumps, the sprung assembly can articulate, flop and bounce around however they like without disturbing the rest of the car.

    The primary purpose of the Nivomat isn't to increase load-handling capability- the car's max payload is still the car's max payload.They just cancel some of the side effects of operating near the max limit: keeps the headlights pointed at the highway instead of the sky, for example. If you want to truly increase payload, bigger tires and brakes should be early on the list.

    I think you've already found some truth there.
     
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  6. tony_2018

    tony_2018 Member

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    1st thing on my agenda are the bushings. Hardrace makes replacements for the ct200. from what I see both the ct and prius share the same lca. I even cross reference to the jdm prius. Next would be to order the rear caster bushing. From here look at springs/shocks/struts.