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Beginner's Tuning Introduction.

Discussion in 'ECU's, Electronics, and Tuning' started by MikeBergy, Feb 28, 2006.

  1. MikeBergy

    MikeBergy Blah blah blah....

    Likes Received:
    Oct 9, 2003
    Central Coast, CALI
    So, this was a pm I received today, from someone genuinely interested in knowing how to tune, specifically using turboedit, but my approach to tuning could be done with any type of tuning software capable of maptracing or datalogging. It is a method that has worked for me in producing a pretty smooth and very responsive naturally aspirated setup, and can be carried over to other engine setups as well. Anyone that has any rebuttals to what I am saying, please do so in an intelligent and respectful manner. We're all in this for the learning, and if you know something about it that I don't (Which I don't doubt, as I myself am still a new tuner), please by all means interject. I haven't personally tuned my ignition maps yet, and am still suffering a very slight knock at around 75% to WOT between 3300ish to redline. If I keep my foot out of it a bit, I can run right at the edge of the safe limit, but I seriously need to get that ignition map pulled back a bit. Any help as to rules of thumb are appreciated, as this is one aspect of tuning I haven't gotten down yet.


    Well, it's sort of an art. If you are running stock compression off boost, then it's okay, and beneficial to run a little leaner, near stoic, or about 14.7. There is no such thing as a 'bad afr'; just lean, stoic, and rich. If you want to get a good tune down, and need help from people that are knowledgeable and are going to be able to help you out, you need to get all the proper terminology, so that they'll understand. For your case, on boost, an afr of 14.7 would be considered 'bad', but it's more intelligible to say you are running too lean, and you'll probably melt a piston running that lean for too long, not to mention you'll probably start knocking. Anyway, with your fuel map, you want it to be smooth. And you want to richen up the fuel mixture as you increase your load. The fuel maps are a function of MAP (Manifold Absolute Pressure) reading, and RPM. I have found that with tuning your TPS (Throttle Position Sensor) is also important.

    So, what I have been doing in my street tunes is tuning from lean areas to rich areas. In my case, I am naturally aspirated, but in the case of a turbocharged vehicle as yours, the fuel and ignition maps are just extended versions of the NA maps, extended into a positive pressure MAP region, and you just have to tune more cells. I started with idle. With idle, there is next to zero load on the engine, as there is nothing slowing it down but internal friction. I'm lazy, so I just started the maptrace while the engine was warming up, and noticed what cells in the trace were getting lit up. With the wideband turned on, I just adjusted those cells to where the idle is smooth, and afr is set to about 14.7. Next, I adjust low load areas of the fuel map, say 1-25% throttle. Turboedit's datalogger has a TPS calibrator in the options menu, so you need to set that while the car is running in order to have a correct throttle calibration in your datalogger. So I set the datalogger and maptrace to log the data and trace cells which are used when the throttle is between 1% and 25%. I say 1% and not just zero, because when you are off the throttle, the ecu turns off the injectors to save gas (except at idle of course), and you don't want those values to screw up you map trace at low loading. So drive around and go through all the gears, trying to stay between 1 and 25% throttle. Turboedit hasn't yet had a target AFR map built into the system, but it does have a setting in the options menu that allows for autotune to adjust the fuel map values in the cells given a certain logged afr, and it's deviation from the target afr you have set in the options menu. For idle, this afr was around 14.7, for low loading, I dropped it to around 14.1-14.2. I tend to richen with an increase in throttle, and richen with an increase in rpm, but to a lesser extent for rpm than throttle; for example, I may richen up from 14.1 to 13 afrs from off throttle to WOT, but may only richen up from 14.3 to 14.1 between 1500 and 4000 rpm (that is just an example, none of the numbers are what I actually have used).

    Anyway, after you are done with this area, you move to the next richer part of your map, medium loading still off boost, and you should shoot for around 13.5-14ish with your throttle from 25 to 50%. In the case you are in low boost at this point, you should aim for around 12.5-12.3ish. Repeat the same process as you did for the low loading area.

    After that, you want to hit the medium high loading areas of your map, around 50-75% throttle. If you are tuning off boost, which I would recommend before tuning the boost sections of your maps, You should still aim for around 13.5-14ish. For NA high compression engines, aim for afrs of around 13. Repeat the same process as before. See a trend?

    Wide open throttle should be tuned last IMO, as it is the easiest area to tune, yet most dangerous area to mess around with, as this is the place where all the knocks happen, and all the power is made. Tune for around 13.5 off boost. For the boost section of the map at WOT, aim for 12-12.5 richening up the mixture fairly linearly as boost increases. You should see afrs around 12 for full boost, WOT. Keep in mind that you might be able to run a bit leaner, and with a little more timing to make more power, but stay safe with a street tune and stay at around 12:1. These seem to be where most boost guys want to be, I have no personal experience with tuning boosted cars, but I do just see it as a longer tuning session. Turbo guys also have to worry about pulling timing for boost, and you can look to see what guys reccomend on how much timing to pull in terms of degrees of advance per pound of boost. I am not versed in this aspect of tuning, so I couldn't tell you. Maybe ask brian (pissedoffsol) as he seems to know a good bit about tuning turbo'd hondas, and just tuning in general.

    That's about the limit of my knowledge of tuning from the actual tuning of the car perspective. I could go on and on about theory, and what you need to do if you do such and such to the engine. One little pointer I will tell you though. Try to tune on a cool day, or maybe even a night, because you want to tune at a time when your maps are going to run the most lean. You don't want to tune during a warm day only to have your engine knock at night because the air charge got 20% denser as a result of the drop in temp. Off throttle, your O2 sensor will take car of most of this if it sees a lean mixture, and will correct it to a certain degree. It won't however be able to fix it in boost, when it really matters. You'll be running to rich for the O2 sensor to know what to do with itself, and so it will either throw a code if the O2 sensor is turned on, or, in 99.9999% of all the cases I see, the O2 sensor is turned off in boost, and so the ecu runs in open loop mode and reads the fuel values directly off of the map. You need to make sure that the fuel maps are going to be feeding enough fuel to the system on those colder days/nights.

  2. pissedoffsol

    pissedoffsol RETIRED

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    Sep 28, 2002
    Retirement Home
    :thumbsup: good post.
  3. kaoskustoms

    kaoskustoms Senior Member

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    Jan 6, 2003
    casper wyoming man
    good info this should be in the main forum
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