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Thread: GM495HP Crate Engine Idle Tuning and T42 4L70E Trans tuning

  1. #1

    Default GM495HP Crate Engine Idle Tuning and T42 4L70E Trans tuning

    Hey guys have a 53 Chevy Pickup we built that a customer insisted on running the GM 480/495HP Crate LS3 in with the 4L70E Trans. I dynoed the Truck and everything seemed good, but I cannot get this thing to Idle and work out nice at part throttle tip in and drive especially with the A/C on it will almost always die after a light throttle tip in then release.
    PCM is an E38 from an 08 Chevy Pickup that is matched to the T42 module. Here are the issues Im having on the Engine Side of Things

    1- The Idle issues where it wants to die when you give it a light throttle tip in then step on the brakes the Idle Drops when I do this around 2-300 RPM's it can catch itself without A/C on, but when It's on it almost always Dies.
    2- I cannot get the PE tables to cooperate it was Rich on the dyno and I cannot get this thing to do what I want it to do as far as AFR's Go.

    I am also having issues with the Trans shifting decently and working properly. Trans Issues are as follows.

    1-first off it bangs into gear Hard when you go from Park to Drive.
    2- It has a weird cut loose where it does not shift 2-3 shift then bangs off limiter
    3- When I just drove it it wanted to almost go into a Limp mode when I hammered it in 2nd gear.

    This seems like a lot, but I have never run this much engine with a 4L60E based Trans and E38 PCM. Any help would be greatly appreciated here, This has been kicking my ass for over a week. If it's easier/ better to go MAFless I will gladly do that, but have never done it on an E38 and am not sure how to set that up.

  2. #2
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    Post up a pic of the whole intake piping also showing the MAF location, they are tuned pretty good we have a 525hp LS3 I tuned on the dyno and it ran good out of the box assuming you have the OEM tune for it. We used a strait inlet with no bends my dad built a nice cold air cowl induction for the car and it took quite a few try's to find a place were the MAF was happy he was about to burn the thing because it ran good before and he puts it in the car and no werky after haha.
    Last edited by rcr1978; August 23rd, 2018 at 01:27 PM.
    04 LB7
    2010 LMM
    2015 LML

  3. #3

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    Quote Originally Posted by rcr1978 View Post
    Post up a pic of the whole intake piping also showing the MAF location, they are tuned pretty good we have a 525hp LS3 I tuned on the dyno and it ran good out of the box assuming you have the OEM tune for it. We used a strait inlet with no bends my dad built a nice cold air cowl induction for the car and it took quite a few try's to find a place were the MAF was happy he was about to burn the thing because it ran good before and he puts it in the car and no werky after haha.
    I used one of our stand alone E38 harnesses and T42 harness with some stock truck PCM and TCM.

  4. #4
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    Here's a bunch of E-rod files to look through might find something to help.

    https://forum.efilive.com/showthread...OD-Calibration
    04 LB7
    2010 LMM
    2015 LML

  5. #5

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    Unfortunately I am extremely limited on room in this 53 Chevy so the Intake consists of a 90 Degree Elbow with a Spectre MAF holder about 4" Long with an LS3/7 MAF installed in it and a Large Cone Filter. Also appreciate the Link, but I have an E38 PCM and I believe most of the E-Rod or connect and cruise run E67 PCM's. Either way I did not see one for the 480/495 HP package in your list.

  6. #6
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    Yeah I missed the E38 part and those are all E67's sorry.
    04 LB7
    2010 LMM
    2015 LML

  7. #7

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    I took all the Values and copied them over for from the 525HP one you linked, but still has the same issues with dying all the time its mildly better than what I had setup, but the damn thing just will not Idle decent especially with AC on.

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