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456 front shock? stiffness?

Discussion in '456/550/575' started by ccr2002, Mar 2, 2009.

  1. ccr2002

    ccr2002 Karting

    Oct 31, 2003
    150
    Salt Lake City, UT
    So, I've really enjoyed the way my 456 handles with the 550 front shocks installed but i'm getting tired of the suspension fault icon and would like the option of sport etc, so i'm sending my shocks back to bilstein to have them tightened up. They told me that they could increase stiffness by a certain percentage or his a specific number and that sport mode would just increase it accordingly. Based on earlier posts, it seems that in normal setting the front shocks are pretty soft but at speed and in sport they are much stiffer...so question is: What would be the ideal increase in stiffness I should ask them to hit. I'll probably just drive in sport most of the time.

    One small correction: the spring rates should be read as mm/Kg and not mm/N.

    "Here the important figures to compare.

    -------------550------------456

    Wheelbase--2500 mm-------2600 mm
    Front track--1632 mm------1585 mm
    Rear track---1686 mm------1606 mm
    Front tyres 255/40 18------255/45 17
    Rear Tyres 295/35 18------285/40/17

    Weight------1690 Kg-------1690 Kg

    Spring rate
    Front-------18 mm/Kg------20 mm/Kg
    Rear--------26 mm/Kg------30 mm/Kg

    Shocks Compression
    Soft when driving slow and setting:normal, firm when driving fast and setting:sport
    Front Soft 380N@0.13m/s--190@0,13m/s
    ---------- 790N@0,52m/s--625@0,52m/s
    Front Firm 560N@0,13m/s--520@0,13m/s
    ---------1005N@0,52m/s--910@0,52m/s

    Rear soft 305N@0,13m/s---150@0,13m/s
    ---------600N@0,52m/s---485@0,52m/s
    Rear Firm 325N@0,13m/s---445@0,13m/s
    ---------665N@0,52m/s---735@0,52m/s

    Widening the front trach should only be done with great care because it can make the car nervous when hitting small objects on the road and can also cause a "tramline" effect.
    The spring rates seem quit O.K. because the 456 has the firmer springs, although both cars have the same weight.
    The best next thing to me seems to change the front shocks.
    When driving slow, the front feels blubbery, which is explained by the figures above.
    This should be improved to a great extend when changing to 550 shocks."


    What do you think?
     
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  3. t024484

    t024484 Karting

    Nov 9, 2006
    171
    Netherlands
    Full Name:
    Hans A. Polak
    What exactly is your question.
    Do you want to go back to your original 456 shocks after having made them firmer ?
    If you are happy with the 550 shocks, you know how stiff they have to be made, haven't you.

    Hans
     
  4. kosmo

    kosmo Formula 3

    Oct 19, 2008
    1,438
    BIg D
    is a rebuild of the shock required or is it more of an adjustment?
     
  5. ccr2002

    ccr2002 Karting

    Oct 31, 2003
    150
    Salt Lake City, UT
    #4 ccr2002, Mar 2, 2009
    Last edited: Mar 2, 2009
    yeah, that maybe was confusing. i guess i just want to adjust the original 456 shock so that on sport mode it is as stiff as the 550 shock but still is more stiff at baseline than the original 456 setting....i guess you're right, i probably should just set the "stiff" or sport mode to equal the 550 and take whatever that leaves the "normal" setting. Just wondering if anyone has tried a specific number and what they thought.

    As you can see the percent increase from soft to firm is much greater in the 456. maybe i'll aim higher than the 550 in firm and then i'll be good around town in normal with a firmer ride. even stiffer at speed probably can't hurt.
     
  6. oss117

    oss117 F1 Rookie

    Jan 26, 2006
    4,043
    Plantation, Florida
    Full Name:
    Alfredo
    Your best bet is to have the original shocks re-calibrated to your liking by Bilstein: youll get the stiffness that you are looking for and you'll get rid of the light at the same time.
    Best of all it will not break your bank account.
     
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  8. SonomaRik

    SonomaRik F1 Veteran
    Silver Subscribed

    Dec 15, 2006
    6,715
    Sonoma, CA
    maybe it's just me [more than likely] but wouldn't the ECUs need some adjustment/SW-programming or such to help?

    I know if the shocks are hard set/stiffened, that the ECU will just shift accordingly and go with whatever is in there, but also wondering if overstiffening is a problem for that ECU to make 'good adjustments'.

    ALSO,

    Make sure to check out all items down there, if stiffening, like motor mounts, joints etc....not saying out of specs, but DO notice 456 mounts to be ... of issue.

    rik
     
  9. ccr2002

    ccr2002 Karting

    Oct 31, 2003
    150
    Salt Lake City, UT
    thanks for the reply...all the mounts and everything are fine...the was great with the original shocks...just not as tight as the 550 i had. It's better now but i'd like to get the OEM shocks back in to get rid of the suspension fault. i'll post after i get them back from bilstein
    ccr
     
  10. fatbillybob

    fatbillybob Two Time F1 World Champ
    Consultant Owner

    Aug 10, 2002
    20,353
    socal
    If the 550 shock is plug and play why do you get a fault? As a previous poster mentioned maybe the shock ecu looks for a certain feedback and if you revalve a 456 shock to a 550 spec you may get faults. I have no clue how these shock ecu's work. Personally these at best are single adjustable shocks. I think the hot ticket would be to dyno a known good shock and then revalve a two way adjustable shock to those settings as an initial setting then you can have what ferrari intended and taylor to your own needs too. You would also have many more adjustments just not computerized on the fly. But we would need to find out how to turn off the suspension light. I wonder if you just unplugged the suspension ecu if it stopped talking to the light.
     
  11. ccr2002

    ccr2002 Karting

    Oct 31, 2003
    150
    Salt Lake City, UT
    I'll ask the guys at Harris again, but I was told that just plugging in the ecu or actuator gives the fault...as does unplugging it. If the 456 shock is connected, even w/o installing it...the light goes out. Must be some internal code signal. That's why we thought adjusting the original 456 shocks, despite their new setting, will probably work.

    I'm interested in the above posts about Bilstein's problems. If there was another system out there that didn't cause the fault I'd maybe give it a try. I really don't have a big need for the "normal" mode.

    Anyone, anywhere ever try something else?
    ccr
     
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  13. fatbillybob

    fatbillybob Two Time F1 World Champ
    Consultant Owner

    Aug 10, 2002
    20,353
    socal
    If you are messing with the shocks now I wonder if the red actuator actually needs to feel the shock. I wonder if you unplugged the actuator from the shock and left it, if the light would go out or if there is actual shock feedback.
     

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