Spring Rates For Bigger Rear Swaybars

Discussion in 'Suspension and Chassis' started by HF Bass, Jan 23, 2019.

  1. HF Bass

    HF Bass TMO Intermediate

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    I've noticed alot of you guys are running the smaller rear sway like an 18mm. I have the whiteline 27mm in the rear right now. I really like how the car feels on the shock/strut setup I have. I'm wanting to move to a coilover in the next year, and
    I've been researching some brands. I still get stumped on a what a good spring rate would be on a set of coilovers. Most of what I find on here is guys with the smaller bar out back. So some of y'all big bar guys let me know what y'all are running and how you like it.

    Also on a square setup 18x10s with 275/35s.
     
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  2. VoodooBoss

    VoodooBoss Rick Moderator

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    What sway bar do you have upfront? On stock suspension most move to a smaller rear sway bay when moving to a square setup in order to keep the car balanced.
     
  3. HF Bass

    HF Bass TMO Intermediate

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    I have the 33mm whiteline. I bought the front and rear together in their kit.
     
    Last edited: Jan 28, 2019
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  4. VoodooBoss

    VoodooBoss Rick Moderator

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    Ok that makes sense. :)
     
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  5. HF Bass

    HF Bass TMO Intermediate

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    Yeah I had installed them before I found this forum, and I hadn't got to do much digging. Idk if I would want to completely change the route I'm going now. I do like how the car feels now, but with these new bars I can feel how my springs are a bit soft now
     
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  6. Norm Peterson

    Norm Peterson Corner Barstool Sitter

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    Where do you have your bar adjustments set at now?

    Seems to me with four adjustments on each bar there ought to be some other combination of settings that'd bring the handling balance with different springs back about to where it is now.


    Sort of off-topic, but all I'm seeing in Whiteline front bars for an S197 is 33mm.


    Norm
     
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  7. HF Bass

    HF Bass TMO Intermediate

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    The front bar is a 33mm my bad, but I have the front full stiff, and the rear one notch from full stiff. The springs I have are 230 F / 200 R. I just want to make sure when I move to coilovers I'm not gonna be way off on a good spring rate.
     
  8. DocB

    DocB TMO Advanced

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    Presently, or when you move to coil-overs, how do you use the car most of the time?
     
  9. HF Bass

    HF Bass TMO Intermediate

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    Track duty only with occasional weekend driving. I'm not worried to change up the streetability or comfort.
     
  10. Grant 302

    Grant 302 OPM Spent: $665,833 Moderator

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    Which brand or compound of 275?

    My feeling is that with the Whiteline rear bar that you wouldn't want to stray too far from the 200 to 250 lb./in. rates in the back.

    I think it would 'pair' with rates in the 350-500 lb./in. range, not knowing where the rates are for the Whiteline front bar.

    -----

    That said, I wouldn't advise making the coilover and spring rate choices based on the bars you have.

    What do you dislike or think can be improved on your current springs? Or...why do you want to go to coilovers? What is the suspension lacking to you with regard to the tire you're running?

    -----

    If there are 'I don't knows' in the answers...perhaps contact a shop like Vorshlag who has used Whiteline products in their S197 race car in the past.
     
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  11. HF Bass

    HF Bass TMO Intermediate

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    Thanks for the advice. The big test is I just moved to 200tw dunlop direzza zii's so gonna see how the suspension fairs with a stickier tire. Next event is in March so I'll be able to get some feedback soon. There's some definite unknowns that I would love to talk with some guys at Vorshlag or Cortex.

    I wanted to see if there are any guys out there running a bigger rear bar. Get a little comparison of their builds and what they like the car to feel like to see if it could help me any. I'm down for any kind of help I can get lol. Wouldn't the spring rates I would go for be a bit different in the rear due to the more tight rear end?
     
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  12. Grant 302

    Grant 302 OPM Spent: $665,833 Moderator

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    Yes, at least in theory...and also why I did suggest lighter springs in the back than I would compared to someone who would run a thinner bar.

    The main reason why I wouldn't recommend going that way is in the different rates of weight transfer as the car rolls in a turn. Thicker bars transfer weight faster and reduce grip. I would always recommend the least bar that allows your suspension to travel within the working geometry for *any* given setup.

    But the subject is a LOT more complicated than just that. If I would characterize and oversimplify the issue, it would be like putting a band-aid on top of a band-aid to fix the problem.
     
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  13. HF Bass

    HF Bass TMO Intermediate

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    Thanks alot man. We'll see how the car feels with the new tires and start pinpointing certain things to try and narrow down the best route.
     
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  14. HF Bass

    HF Bass TMO Intermediate

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    Took the car out to Road Atlanta and got a little dry time to play around with the new tires. This definitely threw out my want for coilovers for a good while. The car felt fantastic with the new bars and a 200tw tire. There are new limits I need to find before I can safely decide the next route for the suspension. Thanks again @Grant 302
     
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