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Thread: 2010 545rfe explanations

  1. #1
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    2010 545rfe explanations

    I have just picked up HPT to play around with my 2010 1500 5.7L.
    As far as HPT terminology it is a foreign language. I have a fairly extensive knowledge of automatic transmissions, but am lost in terms of which options do what. For starters, the Pressure options are not just specified values. They are a duty cycle graph. There are other threads on this but they specify max PSI values and such that I do not see anywhere. I'm wondering if that's a model/year difference issue . Also there are thread explanations for desired acceleration offset but nothing on ramp rate of acceleration. Any extra explanation on these parameters would be greatly appreciated. I have attached the stock tune so the transmission parameters are reviewable.
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    Lightbulb

    So I figured out how to actually put HPT into advanced view. Found the Line pressure options I was looking for earlier. However, any info on Ramp Rate would still be very appreciated. Thanks

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    Ramp rate is just how aggressively it applies the acceleration slew tables.

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    Quote Originally Posted by Jim P View Post
    Ramp rate is just how aggressively it applies the acceleration slew tables.
    OK thank you. Any idea what units it is measured in? So the Desired acceleration options are shift speed, and Ramp rate is the rate at which the shift speed is performed? Im assuming ramp rate is a ratio then, In example 1-2 shift speed is 7,000rpm/s and ramp rate is x1.3 that. Or am I missing the whole concept?

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    Ramp rate of acceleration is a unitless number, it?s a gain, the higher the number the more aggressive it is at applying the desired acceleration slew tables. You have an A and a B, one is for off going clutches and the other is for oncoming clutches. Shift duty cycle will make it shift faster. Datalogs of the transmission helps a lot to see what?s going on.

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    Quote Originally Posted by Jim P View Post
    Ramp rate of acceleration is a unitless number, it?s a gain, the higher the number the more aggressive it is at applying the desired acceleration slew tables. You have an A and a B, one is for off going clutches and the other is for oncoming clutches. Shift duty cycle will make it shift faster. Datalogs of the transmission helps a lot to see what?s going on.
    Fair enough, now that I'm not completely in the dark I do feel comfortable logging and tweaking this parameter. Thank you for your insight.