• Welcome to SVTPerformance!

Learning to tune

Discussion in 'Tuning À la carte' started by wirelessguy2005, Apr 15, 2019.

  1. wirelessguy2005

    wirelessguy2005 4S FED Established Member

    Messages:
    70
    Joined:
    Mar 10, 2019
    Location:
    NE Indiana
    I recently converted my 97 Cobra with a Kenne Bell over to e85 and I am getting curious about the idea of starting to tune the car myself. After a recently failed (and very expensive) tuning session with a well know shop i really started warming up to the idea of tuning my own car. My question is how difficult is it really to learn? I have read plenty of information on this forum as well as others and have heard plenty of guys talk about doing it but very few seem to actually follow thru. I currently have an SCT x4 handheld but after hearing some of the drawbacks of this software in another thread it has made me start wondering if there is a better option. I have heard a few guys reference the quarter horse and that sounds like a good option but how difficult is it to learn the software associated with that? Any help anyone can offer is greatly appreciated.
     
  2. decipha

    decipha EFI Dyno Tuning Established Member

    Messages:
    633
    Joined:
    Jul 12, 2008
    Location:
    New Orleans, LA
    it takes most people about a year of constant fiddling and dedication before they are knowledgable enough and comfortable enough to tune other vehicles. And tuner is used loosely. There are hundreds of so called tuners out there that don't know the first thing about tuning - 1st thing as in see #1 below lol.

    off the top of my head, in my opinion in order to be a successful tuner there are at least 4 basic things you have to know

    1) the complete operation and intricacies of how the specific engine your tuning mechanically functions and how everything works together. This is how you know what changes need to be made for the modifications a vehicle has. And how your tuning changes affect different things like ignition timing and its affects on emissions as well as performance and fueling how it affects fuel economy, catalytic efficiency, exhaust valve temps etc...

    2) tuning is computer programming so you have to at least know the bare basics to programming, i.e. how an integrated circuit operates commands in and commands out, this will help you understand your algorithms and logic flow. This is how you know what your changes actually do to the engine and how the vehicle/engine will respond.

    3) you have to have a full understanding of the electronics and functioning of all your sensors in order to interpret the data the sensors are giving you in order to interpret datalogs. Computers are just calculators. Tuning is just making the computer do what you want. For any given condition a value will be returned and you as the tuner have to know what that value should be. That way you know the difference between a good value or a bad value and how to make the computer respond to those values. In short what to adjust based on what data the sensors are giving the computer in order to make it do what you want. i.e. the parameters to adjust for any given condition and by how much.

    4) This is the hardest for most people to understand. It is imperative that you understand that an engine is simply an air pump. The more air in the more horsepower it makes. And that horsepower is only a measurement of time distance and weight. The ONLY accurate way to measure horsepower is at the track. Time == et. Distance == 1/4 mile. Weight == actual vehicle weight. In short, this is why hp == tq at 5252 rpm. And hp == tq * rpm / 5252. Thus, horsepower only matters above 5252 rpm and below that torque is what your concerned with.

    Only then you can proceed with tuning. And that in itself gets involved too. At a minimum you need to know the following:

    detonation
    pre ignition
    stoichiometry
    how to read plugs

    with experience and time everything else will come to you.
     
  3. DSG2003Mach1

    DSG2003Mach1 Well-Known Member Premium Member Established Member

    Messages:
    8,602
    Joined:
    Apr 15, 2004
    Location:
    Central Fl
    I’ve only played with pro racer software and taking 5 minutes for every change sucks out loud. My MAF value was off, it took 5-6 tries just to get it to hold any kind of idle, I was already annoyed.
     
  4. decipha

    decipha EFI Dyno Tuning Established Member

    Messages:
    633
    Joined:
    Jul 12, 2008
    Location:
    New Orleans, LA
    yea realtime tuning is leaps and bounds easier. You can make changes literally in thw time it takes you to press the keys on the keyboard.
     
  5. wirelessguy2005

    wirelessguy2005 4S FED Established Member

    Messages:
    70
    Joined:
    Mar 10, 2019
    Location:
    NE Indiana
    I have a descent understanding of the basics that you mentioned. My next question: is the SCT pro racer software more user friendly or the software that you would use with the quarter horse?
     
  6. decipha

    decipha EFI Dyno Tuning Established Member

    Messages:
    633
    Joined:
    Jul 12, 2008
    Location:
    New Orleans, LA
    neither, you really have to know what your doing either way. The benefit with the qh is that u can feel the changes right away so it makes it easier to play with the tune while learning.
     
    LaserRed_Snake likes this.
  7. wirelessguy2005

    wirelessguy2005 4S FED Established Member

    Messages:
    70
    Joined:
    Mar 10, 2019
    Location:
    NE Indiana
    Decipha,

    If I have an existing SCT tune in the car do I have to start all over when using the quarter horse or can I build on the existing tune?
     
  8. decipha

    decipha EFI Dyno Tuning Established Member

    Messages:
    633
    Joined:
    Jul 12, 2008
    Location:
    New Orleans, LA
    the quarterhorse gives you full control of the ecu you can do anything you want with it

    you can read the sct tune you have on it now and continue where you left off. Return the handheld back to stock and read the stock tune as well and either keep it as a backup, use it to compare changes for reference or tune from it if you want

    unlike sct there is no limitations with the qh you can do anything you want

    you having a 96-97 ecu (cdan4) you cant datalog with the qh and tunerpro right now. I have a major update im rolling out later this year for tunerpro and the 96-97 vehicles specifically. So until then datalogging on the 89-95 ecus is fine and the 98-04 ecu but the 96-97 ecus specifically will have to wait til I roll out the update in a few months. If you wanted to you can go to any u pull it yard and get an ecu out of a 98 gt/cobra and use that if you must datalog through tunerpro. In 98 thr GTs and cobras got the same ecu and is plug and play on the 96-97 cobras.

    so unless you swap the ecu for now go ahead an unmarry the xcal but hang on to it for logging for now
     

Share This Page