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Thread: 2017 SRT8 pcm issue

  1. #1
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    2017 SRT8 pcm issue

    We're working on a 2017 SRT8 Jeep with a procharger. The pcm was unlocked by Diablosport and tuned using CMR. The vehicle made great power and ran well but had an intermitent stalling issue that required an ecu reset to restart. The calibration was gone over by DS tech support several times and they offered no suggestions as to the cause of the problem.
    We flashed the pcm back to stock and tuned it with HPT using most of the existing values from the DS tune. Once again the car ran great and made over 850hp on 12psi, BUT the stalling and needing reset issue is still there. I have had both HPT and CMR for a long time and have to say that HPT is far superior to DS especially with the later models.
    Any input or questions/suggestions are welcomed.

  2. #2
    I did the same. Diablo is more for the bolt on mod type folk in my opinion. I have been using my hp now on my heavily notified 2017 gc Srt. Question how do you like that pro charger set up. I’m not sold for the price Vera the power output I’m putting out a lot of power on my natural aspiration. The panels you can play with using the hp I love.

  3. #3
    The problem I found is that the Ds perimeters are set up a lil different so I had to go in and fine tune the hp panels to soot the set up

  4. #4
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    This is a 426 forged engine and the supercharger is a larger F1S. I didn't build the vehicle and there are many problems with this particular setup for instance, this sp should have a cogged or at least a 10 row belt. This one uses the stock belt width so slipping is a problem. Also, the large intercooler is mounted behind the bumper so IATs are always high. I need to find a solution to their stalling/reset issue to make this car viable. Don't beleive that it's a tuning issue at this point. Resetting the ecu really only resets adaptations so I don't understand why that's the only way to get the engine to restart after it quits running.
    I had a similar issue many years ago with an Audi RS6 that I had tuned. After so many key cycles it would get an eeprom error code then would go into limp mode. Turned out to be a hidden checksum that the tuning software didn't know about and recalculate correctly.
    Adding one more thought about the difference between the DS and HPT, it seems that the prevailing thought on the DS side is to leave NN on which is what was done originally. It seems to me that most info on the HPT side says that really isn't the best way with a modified vehicle and should be turned off in this case. I tend to agree with that.

  5. #5
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    Quote Originally Posted by jbehe View Post
    This is a 426 forged engine and the supercharger is a larger F1S. I didn't build the vehicle and there are many problems with this particular setup for instance, this sp should have a cogged or at least a 10 row belt. This one uses the stock belt width so slipping is a problem. Also, the large intercooler is mounted behind the bumper so IATs are always high. I need to find a solution to their stalling/reset issue to make this car viable. Don't beleive that it's a tuning issue at this point. Resetting the ecu really only resets adaptations so I don't understand why that's the only way to get the engine to restart after it quits running.
    I had a similar issue many years ago with an Audi RS6 that I had tuned. After so many key cycles it would get an eeprom error code then would go into limp mode. Turned out to be a hidden checksum that the tuning software didn't know about and recalculate correctly.
    Adding one more thought about the difference between the DS and HPT, it seems that the prevailing thought on the DS side is to leave NN on which is what was done originally. It seems to me that most info on the HPT side says that really isn't the best way with a modified vehicle and should be turned off in this case. I tend to agree with that.
    Well even the Tuning School recommends leaving NN on unless you are running a big cam and/or large displacement (426). So in this case NN off would be the way to go. Just a wild shot in the dark but did you confirm Baro learn is turned off in the tune? Also, have you tried moving the fuel trim breakpoints? Just thinking that reseting the adaptives is always required it could be fuel trim is being taught incorrectly.
    Last edited by Homer; 1 Week Ago at 09:26 AM.

  6. #6
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    Baro learn is off. The ltfts are +-4% with stfts +-2%.

  7. #7
    Then numbers look way better then my big cam 426 stroker

  8. #8
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    But yours doesn't have this weird problem so you're way ahead.

  9. #9
    Did you check all your ground circuits. These mopars and crazy with ground issues.