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  1. #1
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    Default Adding injector pulse width

    Im currently using Tunercat for my tuning and was trying to figure out if I wanted to add or subtract my injector pulsewidth what table would I go into? I was thinking to kind of "trick" the pcm into thinking said injector was either bigger or smallar then what it really was. Or im seeing that there is a Battery Voltage vs injector offset. What would be a good table to use?
    1994 Camaro Z-28 M6
    LE 242/248 cam,Crower split ratio rockers,AI 23*Trick Flow heads,JetHot longtube headers,Borla exaust,ewp,pro5.0,hybrid TNT wet kit.

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    IIRC you can use the ECM Constant table and adjust the injector flow rate.

    IIRC you can tell the PCM your using say, 22lb injectors when you really running 24's and you should be able to obtain a longer injector pulse.
    95 Impala SS Clone

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    what would be the advantage to taking away or adding pulsewidth?
    1997 Trans Am M6 13.9@100 bone stock
    13.0@110 with a crappy 2.2 60ft and guessing on shift points.
    reground cam (cc503), 1.6 proform rr's, Longtube headers, cutout on the Ypipe, Moroso cai, LT4 knock module, tune by lt1pcmtuning.com

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    Quote Originally Posted by rsdoherty88 View Post
    what would be the advantage to taking away or adding pulsewidth?
    An easy scenario would be a rich condition at idle. Lets say Ive installed some 60lb injectors. The Injector constant is correct but I'm show 108 on both sides at idle and its clearly running rich. One of the ways to correct this would be to decrease the amount of time the injector is required to squirt. The problem is Tunercat doesn't have this option. The work around for this would be to increase the injector constant or decrease it.
    1994 Camaro Z-28 M6
    LE 242/248 cam,Crower split ratio rockers,AI 23*Trick Flow heads,JetHot longtube headers,Borla exaust,ewp,pro5.0,hybrid TNT wet kit.

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    Thanks, that's good to know because I'm about order JET tuner. I'm finally going to start learning how to tune. I currently have a mail order that's pretty good, but could be better and I don't feel like sending my pcm back to ohio everytime I need an update...Lol.
    1997 Trans Am M6 13.9@100 bone stock
    13.0@110 with a crappy 2.2 60ft and guessing on shift points.
    reground cam (cc503), 1.6 proform rr's, Longtube headers, cutout on the Ypipe, Moroso cai, LT4 knock module, tune by lt1pcmtuning.com

  6. #6
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    Quote Originally Posted by 95ImpySS View Post
    IIRC you can use the ECM Constant table and adjust the injector flow rate.

    IIRC you can tell the PCM your using say, 22lb injectors when you really running 24's and you should be able to obtain a longer injector pulse.
    +1, constant table.

    TunerCATS is the software I went with, the only downside I see is the length of time to find everything. I can't tell you how many hours I have stared at the list of tables trying to decide which will help me. I should probably write it down.

    -Steve

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    Quote Originally Posted by Black96z28 View Post
    I can't tell you how many hours I have stared at the list of tables trying to decide which will help me. I should probably write it down.
    Please do lol. I'm planning on doing the base line tune on my Twin turbo 383. Really don't know what to adjust for fueling. I would rather me do the initial tune for breaking it in, then down the road take it to a dyno and tune it...
    95 Impala SS Clone

  8. #8
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    Quote Originally Posted by 95ImpySS View Post
    Please do lol. I'm planning on doing the base line tune on my Twin turbo 383. Really don't know what to adjust for fueling. I would rather me do the initial tune for breaking it in, then down the road take it to a dyno and tune it...
    Why dont you want to do your own tuning? Are you running a SD or MAf?. Im tuning a Single turbo setup next week. Should be interesting on stock internals!
    1994 Camaro Z-28 M6
    LE 242/248 cam,Crower split ratio rockers,AI 23*Trick Flow heads,JetHot longtube headers,Borla exaust,ewp,pro5.0,hybrid TNT wet kit.

  9. #9
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    Quote Originally Posted by MEAN LT1 View Post
    Why dont you want to do your own tuning? Are you running a SD or MAf?. Im tuning a Single turbo setup next week. Should be interesting on stock internals!
    All depends on how comfortable I feel with tuning. I haven't decided or researched which will be better yet MAF, or SD. I'll be running 2 t70's feeding a 383... Haven't been able to figure out if these things are too big. Figured I'd spend the few extra bucks with an experienced LT1 tuner and protect my hefty investment from going boom...
    95 Impala SS Clone

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