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Thread: S550 lightweight flywheel issues

  1. #1
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    S550 lightweight flywheel issues

    Has anyone experienced idle issues when swapping to a lightweight flywheel in an s550?

    Car didn't do it before the clutch but now it will idle hang if you clutch it going down the road and just keep creeping up. Then when you come to a stop it comes down to a low idle. I'm trying to figure out if there is something wrong with the car or if it just needs a calibration adjustment. We've done a bunch of clutches in s550's and never experienced this.

  2. #2
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    try going to ''idle, torque, decel torque" subtract 30 percent from the entire drive table. have only dealt with this one time and it was on an S550 with an aluminum flywheel.

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    Quote Originally Posted by Cyle_greenhill View Post
    try going to ''idle, torque, decel torque" subtract 30 percent from the entire drive table. have only dealt with this one time and it was on an S550 with an aluminum flywheel.
    maybe it has something to do with inertia tq?

  4. #4
    my car was doing similar with a lighter clutch / flywheel setup. Good info. Ill try it too when it thaws.

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    Quote Originally Posted by Cyle_greenhill View Post
    try going to ''idle, torque, decel torque" subtract 30 percent from the entire drive table. have only dealt with this one time and it was on an S550 with an aluminum flywheel.
    Tried this but it didn't work. Glad to hear some others have experienced this. I never have so didn't want to invest too much time if it was a mechanical issue. I tried going through all of the rpm set points and correcting the torque error and it still didn't help. Not sure what to do next, may have to dig deeper to see if I can find anything related to flywheel mass.

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    Quote Originally Posted by veeefour View Post
    try friction torque
    Ya I tried that. it pretty much has the same effect as correcting the torque error via the torque tables. Corrected the error using idle feedback all the way to like 2500 or something and didn't change a damn thing.

  8. #8
    Senior Tuner veeefour's Avatar
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    try to log it and post it here.

  9. #9
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    Not too long ago I noticed my decel hanging. I kept thinking it was something I did in the tune but I had put everything back to stock and it was still doing it so I adjusted my torque decel numbers and it helped A LOT!
    This post just made me realize what changed, it was my 4C converter.. It's soooo much lighter and smaller than the stock clunker! I never put 2 and 2 together lol... thanks!!

    Regarding this comment
    try going to ''idle, torque, decel torque" subtract 30 percent from the entire drive table. have only dealt with this one time and it was on an S550 with an aluminum flywheel.
    Subtract, are you sure?? "Decel Torque Decay" would be higher = faster Decel - how much torque/sec is lost, right? Higher numbers here definitely made my deceleration happen quicker. OP, Be aware there is also Decel Max Rate (still higher is faster here too) and that I've seen some strategies not have Decel Torque Decay.