Eliminating bounciness of PP suspension

Discussion in 'Suspension, Brakes & Chassis' started by EFI, Apr 19, 2018.

  1. EFI

    EFI Well-Known Member

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    This thing is starting to bug me, and I'll be honest the more I read about it on the forums the more I seem to then notice it while driving.

    Anyway, looking to help eliminate the bounciness of the PP suspension for as cheap as possible...and not because I'm a cheap ass (well I kinda am) but because I mainly do street driving and on smooth roads I think the car handles pretty damn well. So I don't need to go big yet until I get some more track experience or the car becomes more of a track car than street car.

    I'm still a bit confused about what causes this and how to fix it. Do I need new dampers or would a set of slightly stiffer springs be enough (or both)? I've already done the Steeda billet shock mounts and a bunch of other BMR stuff but still riding on the stock PP suspension.
     
  2. Nagare

    Nagare Well-Known Member

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    [MENTION=10281]BmacIL[/MENTION] can tell you all about the BMR springs (SP763) and tag in a few others that have done them as a good pairing with the stock PP suspension since you've already got a few other BMR parts. Since they're minimum drop you shouldn't have to worry about the bump stops either. I haven't seen anyone come back and say anything bad.

    I've got Steeda Sport Linears and love them (based on the rates they're firmer than the SP763). They improved the ride without it being harsh imo and go much better with the rest of my setup. With a discount code they're both the same price, I'm biased towards Steeda based on my experience with them thus far.
     
  3. tj@steeda

    tj@steeda Well-Known Member
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    EFI - happy to help! You can send me your contact info & we can get you dialed in ... let me know!

    TJ
     
  4. wildcatgoal

    wildcatgoal @sirboom_photography

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    Rear shock mounts from Steeda were responsible for eliminating as much as is going to get eliminated from this IRS design.
     
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  5. qtrracer

    qtrracer Well-Known Member

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    Shocks/struts control the springs in compression and rebound. If there is "bounciness", it's likely the springs are overpowering the strut/shock valving. If there was valve adjustment, you probably need more rebound to slow that piece down. Adding more spring rate will make the problem worse. Have you checked whether the shocks/struts are leaking?
     
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  6. Bridgie

    Bridgie Well-Known Member

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    Swift springs Spec R sorted it for me, with elimination of any bounce, coupled with a 1” lower stance.
    I also track my car and the swift springs have performed exceptionally well.
     
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  7. BMR Tech

    BMR Tech Well-Known Member
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    First step.

    Trim 5/8 off of the rear bumpstops.

    Then go from there. :)
     
  8. Bluemustang

    Bluemustang Well-Known Member

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    Based on my experience with the bounce, my theory is that the billet shock mounts control higher frequency oscillations like you might get at slower speeds/bumps sometimes. The bounce is either 1. riding on bumpstops or 2. Not having enough shock damping. I don’t know for sure but that’s my feeling based on pre/post trimming bumpstops and pre/post install of billet shock mounts, as well as running 3 different spring/shock setups.
     
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  9. qtrracer

    qtrracer Well-Known Member

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    Assuming the ride isn't abruptly harsh (bump-stop), then the spring compression and rebound is not being controlled by the damper. These spring dynamics are moving up and down - or oscillating - as the car moves. This may also be caused by a mismatch between the front and rear rates causing the car to "pitch" out of level ride.
     
  10. NightmareMoon

    NightmareMoon Well-Known Member

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    The PP shocks are just a bit weak for the high speed highway bumps. Its not a bad shock, but highway expansion joints tend to bounce it. Billet rear shock mounts may help a snall amount, but the real fix is to address the shocks.

    An adjustable shock like the Koni or Steeda adj allow you some room to tweak for personal taste, but a fixed steeda, Ford performance, or bilstein shock should pair well with the stock sprig rates for a less bouncy ride. Me, I'd go adjustable so you can find what you like.
     
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  11. Roadway 5.0

    Roadway 5.0 Strassejager

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    #11 Roadway 5.0, Apr 23, 2018
    Last edited: Apr 23, 2018
    OP: I’ll reiterate what many have said—address your shocks. If you’re looking for the least expensive, and most effective solution, I recommend a pair of Steeda adjustable rear shocks.

    Generally I don’t push adjustable dampers (I get obsessive over each click and end up losing sleep) but in your case, and that few have tried this combo, they are right for you.

    Ask TJ for a forum discount or wait for a 30 year anniversary sale/memorial day. Scoop up the shock mounts if money allows and you’ll eliminate/reduce the finer frequency oscilations too.
     
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  12. Aubrey

    Aubrey GT4949

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    Ford FR3M8 Race Pack - night and day better!
     
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  13. tj@steeda

    tj@steeda Well-Known Member
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    This!
     
  14. Darkhelmet22

    Darkhelmet22 Well-Known Member

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    I got rid of almost all my bounciness with my set up...
    BMR SP080 springs
    Steeda fixed valve pro-action struts/shocks
    Steeda billet rear shock mounts

    I also have BMR CB005 and steeda diff inserts but those did nothing to stop the bounce.
     
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  15. tj@steeda

    tj@steeda Well-Known Member
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    Thank you for your feedback - when you are ready to go all Steeda, let me know!

    TJ
     
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