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Thread: Touring rear shocks; what is the real difference between sls and coil?

  1. #1
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    Touring rear shocks; what is the real difference between sls and coil?

    Pretty much sums up the question. Not sport- non sport, but coil vs air bag.
    Different part#, and it makes sense that the air bag shock would be much stiffer due to the limited travel of the air bag.
    Took a pair of recently replaced shocks off a coil car, and they feel like regular shocks.
    When chasing a shake on the sls car, removed the shock and it's movement was all but locked, but it did move slowly with time. Problem was a bad tire.
    So is that the difference? Anyone know for sure?

  2. #2
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    The standard suspension could be coils or air springs and they used the same shocks because they had similar ride height and movement.

    The sport suspension was only available with air springs, which were lower than the standard air springs so they were paired with sport shocks.
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  3. #3
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    Checking shock applications, i cannot find a shock that is rated for use on both coil and sls.
    So my question is, to anyone who bought new sls application shocks. Did you manually compress them before you installed them?
    And were they rock hard, like nearly impossible to compress? Like a front strut?
    New coil shocks can be cycled with body weight.

  4. #4
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    Quote Originally Posted by wagons ho View Post
    Checking shock applications, i cannot find a shock that is rated for use on both coil and sls.
    So my question is, to anyone who bought new sls application shocks. Did you manually compress them before you installed them?
    And were they rock hard, like nearly impossible to compress? Like a front strut?
    New coil shocks can be cycled with body weight.
    The koni yellows I put in the rear were “compressible” if that’s even a word. They are adjustable by way of compression and rotating the cylinder. Hope that answers your question....


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    I know everyone says that adjustable koni's work with sls.
    But i am working with a theory that the sls requires more in the way of damping to control the air bag dynamics.
    Namely rear tire flutter, felt as a shake at speed. (Like 80-90) And when driving next to the car, and viewing it ,visible. And don't say subframe bushings.
    Danny has a thread about rear shake and i think he's close to lessening it, but i think there is a parial contributing factor of shock valving.
    With all good known wheel and tire, it's wild to see it from outside.

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    I do know that my wagon bottoms out super easily in the rear, regardless of the settings on the Koni shock. Every big bump is a loud crash in the rear. I've cut the bump stops in half in an attempt to create more suspension travel but that hasn't accomplished much.

    One of my friends has a 2002 540it with good condition stock shocks all around (they were replaced by a previous owner) and the rear of his touring feels a lot better on bumps. Maybe there is something to the rear shocks for a 540it. I mean, the shocks do sit at an angle instead of vertically like they're intended to sit, that could be part of it.
    1995 525i 5-speed - Thread

  7. #7
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    WH, I read the title of this thread and pondered, "Wonder if this is a serious question or is WG fish'n for GG for S&G's." ( He's in season FYI)
    I know you know I just konied up and have sls but on a "sport" or "sport-II" (not 100% sure but m-sport so... )
    Scott did all the work.

  8. #8
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    Quote Originally Posted by Plattus1000 View Post
    WH, I read the title of this thread and pondered, "Wonder if this is a serious question or is WG fish'n for GG for S&G's." ( He's in season FYI)
    I know you know I just konied up and have sls but on a "sport" or "sport-II" (not 100% sure but m-sport so... )
    Scott did all the work.
    No, my friend. This is a serious question. Sls shocks are listed as such. I cannot find any brand where the shock is listed fitting both.
    Coil springs have dynamic properties completely different from the air bag. It only makes sense that the shock valving and compression rate would be different.
    Most everything i read says that you want a 10/90 with the 90 on rebound. Thats kind of how I remembering sls shock feeling. Hence the question? This i how the koni's can be acceptable as they have good rebound control, but are probably more 50/50
    And bag length debate is real, sport or standard makes a difference. There is a designed ride height for rolling sleeve type air bags, which is what we have. So lowering an airbag screws with the progressive rate. Lowering a standard to sport height might not trip you up but lowering will. Danny?
    But I will leave that for a separate time in the arnott bag thread.

  9. #9
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    In that case, I hope we find answers.

  10. #10
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    Quote Originally Posted by wagons ho View Post
    No, my friend. This is a serious question. Sls shocks are listed as such. I cannot find any brand where the shock is listed fitting both.
    Coil springs have dynamic properties completely different from the air bag. It only makes sense that the shock valving and compression rate would be different.
    Most everything i read says that you want a 10/90 with the 90 on rebound. Thats kind of how I remembering sls shock feeling. Hence the question? This i how the koni's can be acceptable as they have good rebound control, but are probably more 50/50
    And bag length debate is real, sport or standard makes a difference. There is a designed ride height for rolling sleeve type air bags, which is what we have. So lowering an airbag screws with the progressive rate. Lowering a standard to sport height might not trip you up but lowering will. Danny?
    But I will leave that for a separate time in the arnott bag thread.
    I've always wondered about this., how lowering the car would affect the progressiveness of the airbag.

    Another thing, wasn't there a specific thing one had to do before jacking cars and SUV's with airbags? I know on Range Rovers, you had to raise the ride height before lifting the vehicle, crap like that.
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