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Thread: RPM Limits: What is "Soft Limiter" vs the normal in-gear limit?

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    RPM Limits: What is "Soft Limiter" vs the normal in-gear limit?

    What exactly is soft limiter in the context of the M156?

    Is in-gear 7010rpm limiter a fuel cut limiter and soft limiter is a throttle limiter?

    I'm just not sure where each comes in to play, especially since "soft limiter" has a resume RPM of 5600rpm but I don't know under what circumstances this takes effect because it clearly doesn't in gear.

    Thanks in advance

  2. #2
    Senior Tuner BackyardTurbo_FTW's Avatar
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    If you hover over an item and then read at the bottom of the window it explains what its supposed to do (for the majority of the items its pretty clear)

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    Quote Originally Posted by BackyardTurbo_FTW View Post
    If you hover over an item and then read at the bottom of the window it explains what its supposed to do (for the majority of the items its pretty clear)
    Yeah this one doesn't give any more useful details sadly. I'll just test using trial and error when I get a chance. It's way too hard to get past level 1 support with support tickets.

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    Senior Tuner BackyardTurbo_FTW's Avatar
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    They can help with some stuff but when it comes to the actual tuning they typically dont offer a ton of help. Its a risk thing, if they tell you something and you use it improperly, it becomes "HP Tuners blew up my car". You want the soft limiter 50-100rpm below the actual cutoff. If you want a violent rev limiter, set it 10rpm away. It really will do nothing for you eitherway on this particular car. On turbo cars it can help you get some pop pop between shifts banging off the limiter. Hope that helps

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    Quote Originally Posted by BackyardTurbo_FTW View Post
    They can help with some stuff but when it comes to the actual tuning they typically dont offer a ton of help. Its a risk thing, if they tell you something and you use it improperly, it becomes "HP Tuners blew up my car". You want the soft limiter 50-100rpm below the actual cutoff. If you want a violent rev limiter, set it 10rpm away. It really will do nothing for you eitherway on this particular car. On turbo cars it can help you get some pop pop between shifts banging off the limiter. Hope that helps
    Thanks. Yeah I figured it would work that way with the closer soft limiter RPM gets to fuel cut RPM, the more aggressive the fuel cut. I guess "soft limiter" is the RPM limit using throttle blade then.

    Yeah I kinda majorly over-estimated the level of support and ongoing development offered with HPTuners considering we need 8 vehicle credits just to flash one vehicle. I could have bought the PCMFlash module and the DAMOS for less and had more flexibility and unlimited vehicles too but I opted for HPTuners under the impression that there is a high level of support and ongoing development (adding more tables and features as time goes by). Instead I have since realised that HPTuners Mercedes development seems stagnant and the HPTuners staff who know about the Mercedes ECUs are not contactable by users.

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    Senior Tuner BackyardTurbo_FTW's Avatar
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    Kinda the norm. They release access to vehicles and then trickle out some extra stuff over time. There's plenty there for this car tho to properly tune it so I can't complain. You didnt have it at least when the max timing table and wheel tq tables weren't available. That made it a LOT harder to get some real power out of the car not having access to that stuff. I have no complaints now with it!

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    Quote Originally Posted by BackyardTurbo_FTW View Post
    Kinda the norm. They release access to vehicles and then trickle out some extra stuff over time. There's plenty there for this car tho to properly tune it so I can't complain. You didnt have it at least when the max timing table and wheel tq tables weren't available. That made it a LOT harder to get some real power out of the car not having access to that stuff. I have no complaints now with it!
    Yeah I'm glad I didn't try in the early days. I'm thankful for what is there so far. I just hope they haven't stopped useful development, especially considering the fact that we need 8 vehicle credits for ECU-only tuning.

    When does the wheel torque table actually come in to play? With traction control on only? I do all my logs with TC off and I seem to get full throttle and timing even at low speed so I don't know when this table is limiting. I started this thread about it here:

    https://forum.hptuners.com/showthrea...le-Experiences

  8. #8
    Senior Tuner BackyardTurbo_FTW's Avatar
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    Its a tq limit table. It helps keep the car from going into reduced power mode. That is all

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    Quote Originally Posted by BackyardTurbo_FTW View Post
    Its a tq limit table. It helps keep the car from going into reduced power mode. That is all
    Under what conditions have you seen it active? Just supercharged setups or something? I don't like changing values unless I see it having an effect. I seem to get full power regardless of wheel speed already.