Results 1 to 6 of 6

Thread: M157 increasing boost problem Help ..

  1. #1
    Potential Tuner
    Join Date
    Apr 2020
    Posts
    5

    M157 increasing boost problem Help ..

    I am tuning a m157 2014 cls63s. I have tuned many amg 55 series car using ecm titanium . Using Zeitronix ndash to log Rpm Load IAT Boost timing AFR etc.
    I have tuned many simple cars w hptuners and always had good results. Tuning this cls63 i cant get boost to increase past 12 psi . I hooked up my logging equip w external o2 sensor and logged . Cant get past 12 psi of boost . If somebody is willing to help , I am not cheap for your time willing to offer some $$$. Everything is perfect just NEED MORE BOOST LOL! Thanks , Brian

  2. #2
    Potential Tuner
    Join Date
    Apr 2020
    Posts
    5
    ...
    Attached Files Attached Files
    Last edited by w211savage; 03-24-2024 at 09:00 PM.

  3. #3

  4. #4
    Advanced Tuner
    Join Date
    Jan 2022
    Location
    Southern California
    Posts
    448
    That file looks almost stock, worse actually. I'm sure veeefour, can hook you up, but if you're like me and you prefer to do it yourself, I attached what my first attempt would be.
    Your eng is basically like mine so it seems pretty easy.
    From there you can add even more boost, but I'd want to see what this nets before adding more.

    mattsclschevota.hpt
    '16 E550 Coupe RWD - C207.373 / M278.922 / MED17.7.3 / 722.909

  5. #5
    Potential Tuner
    Join Date
    Apr 2020
    Posts
    5
    Will Give it a try and report back . What main parameters should i be focusing on to increase boost? What parameter directly increases boost?

  6. #6
    Advanced Tuner
    Join Date
    Jan 2022
    Location
    Southern California
    Posts
    448
    Is ECM Titanium not similar? I'm looking for something else, like that, because I suspect HP is causing me problems and I want to use something different to see if the problems follow or not.

    The Max Desired is a limiter, apparently, and I assume for air flow? I bumped it a bit, to start.

    The Wastegate Error Conversion I don't know about, I just put it back to stock.

    Max Torque Driver Input I raised at the top end. On mine I raise it to 900 from ~2500 on up, but I have to keep the 600-1000 oem or the throttle off the line is very touchy. If I have that range at say 500, and I go from a stop, the car lunges and front end rises like I floored it. So it doesn't act like a limiter in that respect, but from ~1500 on up it seems just like a limiter.

    Your Normalized Torque was raised, but that one is apparently part of the math used to calc power, so raising it nets you less power. So I put it back to stock. I guess the way it all works is you give it xx gas and it does all this math and says, ok, I see you want 500hp, lets see what I can do. Then it tries to get there, based on it's calcs. Well, when the math says 500, then it throttles back. If that Normalized # is higher it apparently makes the calculated # higher. So, for example, 450 actual hp could read as 500hp, so it throttles back at 450 and calls it good. Inversely, you lower the # like I do, so it's thinks it's making less than it really is so it drives to make more I lowered mine from 885 to 800 and it helps. I assume this lowers the torque reading you see, but a small price to pay.

    Optimum Torque is part of the net power calc. If feeds Torque to Load so if Opt is low, Tq to Load will be too. Yours had room to bump the top end a bit, so I did, and it will help, but really that's in preparation for the next step which is raising Torque to Load. I/we want to see where your boost is before we get crazy.

    Torque to load is the goal, so to speak. If nothing else is limiting you and the commands get to the 100% row here, then the # in the 100% row is what it'll drive to. I think the deal is a 100 value in the chart is supposed to represent a NA engine at full throttle, so 200 would be about 15psi boost? It doesn't work exactly like that, but ballpark-ish. 200 can net me as much as 22psi, but remember my Normalized Torque and some other stuff are throwing it off so it's trying harder.
    So I left Tq to Load alone to see what boost you get as it is, then you can adjust up from there. Just remember that first one, Max Desired, is a limiter so it may need to be bumped. If this tune works fine then I'd push Max Desired to 220 and see if it responds. If so, then it was limiting you and I'd push it until it's not. If not, then it's not limiting you (yet). I'd raise it way up if it were my car, but it's not, so that's why I only went to 200.

    I also lowered, or clipped, your exhaust temps a bit. Mine won't make power unless I do this, for whatever reason, so I do it by default. I clip mine to at least 1800F, but usually 1750. Yours I put at 1850, because again, not my car.

    And I tweaked your cooling fans so it won't cook when idling. Not sure if you check, but likely getting as high as 230 sitting at light in the summer. Now it should stay ~200-205. Just another default thing I do to tunes I touch. Fyi.

    1.jpg
    2.jpg
    3.jpg
    4.jpg
    '16 E550 Coupe RWD - C207.373 / M278.922 / MED17.7.3 / 722.909