question about stock suspension

Discussion in 'Modifications & DIY how-to' started by Ava, Oct 1, 2006.

  1. Ava

    Ava Member

    So, it's not often that I get to drive Ava (04 STi) out of town. This weekend was one of those not so often occurance out of town, and I ended up missing Heath's install (sorry man). I work about 7 miles from home, where I take local road with very slow traffic. While I understand the stock stiff sport suspension system (try saying that 5 times fast), I'm not sure if it's me or the road that is killing me. I litterally feel everything bump and grove on the road, which is a good thing; however, on bad highway such as 316 and some part of 85, I could imagine the passenger getting car sick from the car bumping up and down. I just wanted to know from other drivers if this is normal for a STi stock suspension? I love how it hugs the road and around corner, so is a side affect of those benefits?
     
  2. onemoresti

    onemoresti Member

    I was pretty happy with the stock suspension. I mean, it's an STi not a GS430. It's gonna be a little uncomfortable on bad roads. On the other hand, I now have a set of Tein Flex coilovers which are obviously better performance wise, but MUCH stiffer. I can't go on long trips with the wife anymore. She complains about the ride and it gives her a headache. I'd like to get something with a smoother ride.
     
  3. Alex

    Alex Community Founder Staff Member

    The stock sti suspension is nortoriously bouncy. In short, the rate of the springs does not match that of the shock. The most common way to fix this is to get a set of springs with a rate that is close to the pinks. The pinks are the jdm sti springs which originally were intended to come on the sti but last minute it was decided that us fat lazy amercians would not enjot the more firm ride. Instead, we got ultra jdm overdamped bouncyness.
     
  4. Ava

    Ava Member

    I see. Thanks for the info, just to confirm it's not just me. I do enjoy the handling and the high performance of the stock, but at time, I can feel the pain of the passengers on rough road. I will start looking for Pinks, thanks for the recomendation!
     
  5. miloman

    miloman Retired Admin

    i have been riding on coilovers for a while on my WRX before i got the STi so i personally thought the stock suspension was way too soft... too much body roll and too much bounce... i upgraded to coilovers almost immediately (<1 week) cuz i found a set at a very good price... yes, its stiffer than stock, and yes, passengers don't enjoy it as much as i do... but hey, im single and i mod my car for me... i don't take work/business associates out to lunch... if someone has a problem with my car being too loud or too bumpy then they are welcome to drive their own car

    just my opinion... i am selfish :evil:
     
  6. GTscoob

    GTscoob Black is Beautiful

    I'll agree with Alex, from my research most STI owners say their cars ride much better with stiffer springs.

    Maybe swap in an 02/03 front passenger seat? I swear my old bugeye seats were a lot cushier than the 04 seats I've got now.
     
  7. miloman

    miloman Retired Admin

    ok, so maybe some mechanic could answer this question... if the stock STi suspension is bouncy, then it is under damped... so the solution should be increasing the damping, not increasing the spring rates... if u use stiffer springs with the factory struts, then the system will be further underdamped hence more oscillations... now i understand that the springs being stiffer may not compress much on small bumps but on bad roads, i'd expect the pinks to oscillate much more than the stock springs... so whats wrong in my logic?
     
  8. calmnothing

    calmnothing Shlimp Flied Lice Supporting Member

    I believe whats happening is that the springs are OVERdamped. Originally supposed to come with stiffer springs but they changed to softer springs last minute without revalving it for the softer springs.
     
  9. miloman

    miloman Retired Admin

    then they should not oscillate at all
     
  10. calmnothing

    calmnothing Shlimp Flied Lice Supporting Member

    Overdamped springs will still oscillate i think. Either way overdamped or underdamped it'll be a bumpy ride
     
  11. calmnothing

    calmnothing Shlimp Flied Lice Supporting Member

    On your coilovers keep the springrate the same. Then jack up the damping like a lot. Then ride around. Bouncy. Then lower the damping by a large amount than what you originally had. Then ride around. Bouncy.
     
  12. miloman

    miloman Retired Admin

    [​IMG]
    critically damped: orange
    over damped: purple
    under damped: green (oscillating)
    if its either critically damped or over damped, the system should not oscillate... now tires losing contact with the ground will also feel like a bounce and should be a side effect of overdamped... however that is not an oscillation in the suspension itself
     
  13. whitey bulger

    whitey bulger New Member

    this was a biiiiiig help, and I was glad to find it. thanks for having posted it.
     
  14. WJM

    WJM Banned

    Yeah...NO.

    Underdamp: bouncy
    Overdamp: too stiff
    JIC: BOUNCY (overdamp on BUMP, not enough rebound)
    Just right: just right.
     
  15. WJM

    WJM Banned

    thats called shitty tires.
     
  16. Alex

    Alex Community Founder Staff Member

    got stiff sidewall ? :p
     
  17. Berzerklo

    Berzerklo Active Member

    You did that in MATLAB didn't you? I would like to take a moment to really appreciate what going to Georgia Tech does to people. :wiggle:
     
  18. WJM

    WJM Banned

    yes. lots.
     

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