High RPM Clutch Hang Up

Discussion in 'GT350 and S550 Technical Forum' started by StigsBaldBrother, May 30, 2016.

  1. StigsBaldBrother

    StigsBaldBrother TMO Advanced

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    I was at Sebring this weekend for the beast's second track outing and experienced a peculiar issue. When shifting at high rpm, around 7500 to 8000, the clutch wouldn't reengage when the clutch pedal would release. It seemed as if the pressure plate, and the clutch pedal too, were stuck for about half a second, then it would reengage like normal. My wife experienced the same thing, so it wasn't my driving style or releasing of the pedal.

    I did change the stock clutch pedal spring for the Steeda one. However, Steeda happened to be at the event and I spoke with Dario, the owner, who said it was just a function of the pressure plate at high RPM and the pedal spring had no effect. I'll take that with a grain of salt seeing that it's his product and I don't know how much testing they did on a GT350, if they tested it at all.

    Have any of you experienced something similar with the stock pedal spring?
     
  2. VoodooBoss

    VoodooBoss Rick Moderator

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    Wait, first you let your wife drive your car on track? ;) You're a lucky guy. My wife won't even go to the track with me.

    And I was just commenting to a friend how trouble free the Gt350 TP and R have been on track. @Moto had his R on track this weekend and @Black Boss has a bunch of track days on his R. I know Moto has the Steeda Spring on his car but I'm not sure about BB. I have the Steeda Spring sitting on my work bench ready to be installed but I doubt it's causing the problem.
     
  3. StigsBaldBrother

    StigsBaldBrother TMO Advanced

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    You got it backwards. My wife let me drive her car on the track. :D We did have to sell her beloved 03 Cobra to get it. The track sessions are my payment, or I guess reward, for doing all of the maintenance and modifications. She's the one doing the Track Attack and 302S day at Ford Racing School in another 2 weeks.

    Other than that, the car was amazing this weekend. We had back to back run groups and the car didn't skip a beat.

    Back on topic: I would tend to agree with you that the spring isn't the issue, if the pedal wasn't stuck to the floor. But then again, it is a hydraulic clutch and the pressure plate should have enough spring force to handle returning to engagement at high RPM. Hopefully some other track junkies will chime in.
     
  4. VoodooBoss

    VoodooBoss Rick Moderator

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    Cool. The pedal sticking was very aggregating in the Boss and I sure hope we don't have widespread issues in the GT350.
     
  5. Flyboygsxr

    Flyboygsxr ADAM

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    Here we go again...Could be due to the fact that you were running back to back run groups so I'm assuming 40 minutes or so without a cool down? That's a long time in the summer to run without a cool down.
     
  6. moto

    moto Ron

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    Yep. No problem with high rpm shifting like the boss. Steeda spring felt very good. Clutch engages/disengages slightly higher than I like, but no issues on the track.
     
  7. TMSBOSS

    TMSBOSS TMO Addict

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    Is there adjustment in the clutch linkage under the dash?
     
  8. moto

    moto Ron

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    Not that I know of. Just the spring(double actually) that was initially way too light for my taste and now after replacing with the lighter single spring, results in a stiffer, more linear, feel. The engagement point appears to not be adjustable.
     
  9. Black Boss

    Black Boss TMO Addict

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    Doubt it's the spring. I have 10+ track days and about 1,400 track miles with no issues on the Stock set-up
     
  10. StigsBaldBrother

    StigsBaldBrother TMO Advanced

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    Argh. We'll I'm certainly not going to take it back to the dealer and ask them to try to recreate the problem. I'll try to do some more diagnosing at the next event. Thanks guys.
     
  11. 8250RPM

    8250RPM TMO Addict

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    Could it be the brake fluid temps? I never understood why they did away with a stand alone clutch cylinder. I actually rather have the cable actuated clutch back.


    Sent from my iPhone using Tapatalk
     
  12. StigsBaldBrother

    StigsBaldBrother TMO Advanced

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    It didn't seem to be temperature dependent as it hesitated the first session out. I didn't know that this was an issue on the Boss. I know the Cobras didn't have this issue, but you also needed to be a weightlifter to depress the clutch. Being able to adjust the release point was amazing too.
     
  13. k98dave

    k98dave TMO Addict

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  14. YellowJacketBoss302

    YellowJacketBoss302 TMO Race

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    please give us an update. Are you still having this issue?
     
  15. StigsBaldBrother

    StigsBaldBrother TMO Advanced

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    Not really sure yet to be honest. I put the stock clutch spring back into it as a test, but I haven't been to a track that I was familiar with enough to get my shift points that high. I was supposed to go back to Sebring in 2 weeks to find out, but they just canceled the event.
     
  16. Froggy47

    Froggy47 TMO Advanced

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    Just came across this. My 2004 z06 (and a lot of other z06 cars) have this well known issue. Clutch pedal sticks down after high rpm shift, will not pop up to reengaged clutch. Many different approaches to fix such as:

    Different (performace) clutch
    Different clutch master and/or slave
    Helper spring to pull pedal back up (I have this)
    High(er) temp clutch fluid (I have this)
    Change clutch fluid when it darkens (Ranger turkey baster method) I do this.
    The ones I do have fixed my problem, I am still on all stock components @ 60k miles.

    My personal opinion is that at extreme/repeated high rpm/heat conditions the design of the clutch itself allows a momentary (and damn annoying if not dangerous) hang up of the parts at disengaged position. Sometimes it stays there for a while. You would think the engineers would account for this in design, but what do I know, just a customer. I think the engineers cave in to other "market research" folks who insist that the few remaining stick drivers want a light, easy to push down pedal, and that nobody REALLY shifts at the red line. SIGH.

    :)
     
  17. StigsBaldBrother

    StigsBaldBrother TMO Advanced

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    Thanks Froggy. It's only an annoyance right now, but I hope that it doesn't get worse as the clutch wears. Been too hot for any decent track events, but I should know more soon.
     
  18. v8 snake

    v8 snake TMO Beginner

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    i have the same issue on my 2018 gt350...
     
  19. racer01

    racer01 TMO Beginner

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    My car did this with the Steeda spring. Figured it was all in my mind and the spring couldn't really be the cause. Put stock spring back in and full throttle redline shifts were normal again. Try going back to stock. Some folks don't appear to have issues. I did. Mine was installed correctly as well...double checked.
     

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