Announcement

Collapse
No announcement yet.

Self-Tuning Computer

Collapse
X
Collapse

  • Self-Tuning Computer

    "The MAF sensor will compensate for your mods".

    No, it wont. It will accept mods, including boost a lot easier than a MAP sensor setup did, because the computers are programmed with the ability to read boost values and higher airflow through the MAF sensor. However, the computer is programmed with hard set tables for the MAF sensor inputs to be converted to g/sec of air. The problem with thinking that the computer will tune itself is that it really doesn't tune. It just adjusts to keep the engine running.


    If you are lean, you will have knock, which the knock sensor will pick up and then the computer will retard your ignition timing. This isn't tuning your spark table, its killing your performance. Its not tuning your fuel tables, its catching up and trying to learn. However, all its really learning is that you have KR at x amount of air and need x amount more fuel. Tuning would be telling the computer what it needs to give the engine the right amount of fuel and then see what your ignition needs to be set at.

    Stock setups aren't even perfect. This is why you can gain power from a tune on a stock motor (kinda obvious right?). If its not perfect or damn close on a stock motor, it can't have a chance when you start to mod. Stock 01 grand am had 5-8 degrees KR and LTFT (thats long term fuel trim, or the BLM for those that have messed with OBD1) of what was supposedly -2 to +5%. Funny thing happens when you start to adjust it though. It gets further off. It went from wanting 5% more fuel in some areas to wanting another 10%! How can that be? Perhaps the KR it was getting was making the fuel requirement less. How will it fix itself if its compensating fuel and spark when fuel was the main factor? Granted it still had KR but it went down as fuel was added, accelerator fuel added, and PE kick in vs TPS % reduced. If you don't understand that, ill put it simply. It wasn't tuned for stock in stock form.

    If you are reading this, and happen to be thinking about a first mod, let me make a suggestion. Make sure you can tune your car, or have it tuned before you do anything. I'm not saying you are gonna blow your motor with a cold air intake. I'm saying you aren't going get the most out of it without the ability to tune.

    • robertisaar
      #4
      robertisaar commented
      Editing a comment
      it's actually not that difficult to do... back in the day(very early 00s), scot sealander did just that.

      problem was that due to the extended RAM not being NV, every time the key went off, the data was lost, so if you wanted to have the PCM learn on it's own with something like 128 or 256 BLM cells, you needed to dump that data before key-off, apply it to the calibration and burn it. otherwise, you would just have a bunch of BLM cells that don't retain data after key-off. while it would work and be considered self-tuning, it would have to relearn every time you start the engine.

      if you used NVRAM(or somehow converted the existing RAM to NV), then at key-off, you could run through a subroutine that would take all of the BLM cells, apply correction to existing VE tables, save those to the NVRAM area and run off of that. that would certainly be self-tuning and effective at that. every time you shut the engine down, new VE tables would be generated automagically. just be sure that your O2 sensor doesn't get bad enough to start reporting false readings and you'll never have to touch a VE table beyond an initial guess.

    • pocket-rocket
      #5
      pocket-rocket commented
      Editing a comment
      I remember Ben telling me about it years ago, but I didn't know the guys name.

      Sent from my HTC One X using Tapatalk 2

    • SappySE107
      #6
      SappySE107 commented
      Editing a comment
      Yeah, I heard about that in the late 90s when I was first getting into all of this. There is a computer setup for the E30 M3s that is self learning, but loses it every time key off so you have to apply the data to get it close, then it goes from there. This is only with a wideband, and I wouldn't want to auto tune off a narrowband anyway.
    Posting comments is disabled.

Article Tags

Collapse

There are no tags yet.

Latest Articles

Collapse

  • Throttle Body Spacer
    bszopi
    Port injection The TB spacer is meant to keep the throttle body cooler, by separating it from the manifold using a phenolic material instead of metal. The misconception is that by adding space behind the TB, you are going to get more torque. The lowered temperature is fine, and is worthwhile (see TB coolant bypass), but the cost of a spacer and the remaining intake manifold temperature doesn't do a whole lot on its own. The performance myth with this device is that it allows more air in, or that it lengthens the runners, or anything else along these lines. The torque curve i...
    05-31-2010, 05:32 PM
  • Throttle Body Heat Shield
    bszopi
    A heat shield made out of aluminum is nothing more than a heat sink. The heat from the heads going to the manifold, with the throttle body attached to it will be a far greater source of heat compared to the exhaust manifold that is not attached to the throttle body. There are better ways to decrease intake air temp, with this one giving absolutely nothing in return for your money.
    05-31-2010, 05:31 PM
  • Throttle Body Coolant Bypass
    bszopi
    This isn't so much a myth, as it is exaggerated. The lines were put in by GM for cold climate conditions, which is said to cause ice to form on TB, which could cause a lot of problems, like a stuck open condition that can cause an accident. There have been no known reports of this happening, but there hasn't been any research either.
    ...
    05-31-2010, 05:30 PM
  • Electric Superchargers
    bszopi
    There are several different versions of this myth floating around.

    Here is one view on why electricity and boost don't mix: Click Here!
    ...
    05-31-2010, 05:28 PM
  • Thermostat
    bszopi
    I'm going to keep this short, because its a simple concept. For years people have been spreading the word that a 160 stat will cause problems. This is true, as it hurts gas milage and MAY cause the cylinder walls to wear faster due to less expansion. If your fan turn on times aren't matched, it can allow a cycle of 160 to 220 degrees back and forth, which will contract and expand the cylinders.
    ...
    05-31-2010, 05:26 PM
  • IAT Resistor Mod
    bszopi
    IAT stands for Intake Air Temperature. It is a simple thermistor that changes its resistance according to the temperature it is at. The idea beind this modification, is that by changing the resistance to that of a cooler interpreted reading, you will get more fuel. While it is true that you will dump more fuel...its false that this is a good idea. Running rich is bad for performance, so you are just wasting your time with adding more fuel in this fashion.
    ...
    05-31-2010, 05:07 PM
Working...
X