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Thread: hellcat boost leak?

  1. #1
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    hellcat boost leak?

    I there a way to tell if the bypass valve is not closing completely causeing boost to bleed off. I'm working on a 2016 Hellcat challenger automatic with a ATI lower pulley, LMI, cat delete with stock manifolds. I'm only seeing around 12.5 max boost. I'm actually tuning this with CMR but I copied the file with Hp so I could post it up here and get a little hope.

  2. #2
    Tuner Ohioc5's Avatar
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    I logged my Hellcat super charger bypass valve while in 500 hp mode and 700 hp mode out of pure curiosity. In 500 HP mode the valve would report around 2.49 V, in 700HP mode it would report 4.49 V. This lead me to believe in 500 HP mode the valve would stay partially open to reduce boost and ultimately HP.

    Your log shows 4.49 v. maybe you're having some belt slip.

    Keep in mind I just started with Dodge, it's pretty foreign to me.
    2016 Hellcat - 800 Miles - It's winter

  3. #3
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    I'd put it back the tune back to stock and see if your boost comes back.

  4. #4
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    I think I will give that a shot. I have the car coming back in a couple weeks. The torque is much lower than I expected to see, only about 610 and I expected to see around 650 torque.

    I noticed in the logs it shows desired sc pressure ratio and that matches almost exactly what it is running. How is desired sc pressure ratio determined or is this even important?

  5. #5
    Tuner Ohioc5's Avatar
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    I have a few questions about the tune in the car. Trying to learn about these Hellcats and the NN.

    The posted tune has 2 to 6 degrees pulled from the WOT spark table. I was thought you could add a degree or 2?
    Is this a 91 octane tune?
    Only 6 of the knock sensors are desensitized. What's the reason for not all 8?
    I see it's an NN tune, but there's no changes to fuel mass or injector pulse width.
    It looks like you're commanding 11.37, will the HC NN maintain commanded AFR with limited fueling corrections?
    Looks like it's pulling an average of 8-10% fuel during the run.

    What's CMR, is that some type of canned tune?

    Is the pulley on the car a 10% ATI?

    I'm not trying to mess up your thread, but some of the things in the tune have me scratching my head.
    Last edited by Ohioc5; 06-20-2017 at 03:07 PM. Reason: Deep thoughts
    2016 Hellcat - 800 Miles - It's winter

  6. #6
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    It is a 10% overdrive pulley. This was a base tune I was starting with. With 91 octane I always need to remove timing, I am running a lot less timing to start with until I get the fuel dialed in.

  7. #7
    Tuner Ohioc5's Avatar
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    Ok, got it.
    Can you post the tune that's currently in the car?
    2016 Hellcat - 800 Miles - It's winter

  8. #8
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    The tune that is currently in the car is with CMR which is a diffrent software. I only read the base file I was using with HP so I could post it up on here . I did not read the last tune I made with HP.

  9. #9
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    Did you ever get this figured out?