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Thread: Noob, Where to start?

  1. #1
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    Noob, Where to start?

    Hello all, as title implies, first time tuning and don't know where to start.
    I've got a 91 Camaro that I've loaded with a 2003 LQ4 6.0L and a 4L80E. Both from work vans... Motor came with the stock harness and P59 PCM.
    I pulled motor apart to clean/inspect and replaced the cam with an Elgin stage 2 cam and new springs. That's the only mods to motor from stock. Installed stage 2 cam hoping to drive with this for about a year and then step up to a turbo kit.
    Finally got everything wired and after disabling VATS it fired right up. Excellent. Now I'm watching the logs and see the STFT and LTFT start increasing and continue to increase. Leads me to believe I'm running lean.
    I figured I better get a MAF (didn't have one at this time), that's probably the root cause... Installed a 3" MAF with a big 4" intake tube/filter and try again with same results. While at the same time I'm YouTube searching and figure I have to perform a cal on the MAF. Attempt that and the videos I was watching was having me plot AFR errors. Shit, I guess I'll install a wideband. I was planning on doing that anyway, just didn't know I'd need it now. Oh well.
    Wideband installed and confirmed I'm running lean. Now I'm reading other sources that I should be tuning the VE tables first with the MAF disabled?

    That's where I'm at... I was introduced to ChopperDoc181 videos from another post here and I can actually understand his videos. Others I've been watching actually are over my head. I see and hear them, just not understanding them...

    So after I get the scanner to be able to communicate and log the wideband data I think I need to attempt a VE tune first? BTW, Camaro is still sitting on blocks and doesn't have a driveshaft yet, so everything is just some idle tuning until I can get out of the garage. Primary focus is an idle tune that wont scorch the heads and pistons...

    I'll try and post a log when I get the AFR input

    All that to ask, "Where to start?" Which tune to try first?

  2. #2
    Tuning Addict 5FDP's Avatar
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    Pick the MAF or the VE to start with, it doesn't really matter so long as you isolate them from each other. Like have the MAF failed for VE tuning and setting it to run on MAF only for MAF tuning. Did you buy a OEM MAF for a truck/van?

    Make sure the exhaust is complete, can be no leaks or open headers for tuning.

    Make sure fuel pressure is steady at 58psi and that your injector flow rate is setup for the fuel system you are running. Like return or returnless. Most 2003's I think are still a return style fuel system, so the calibration may already be correct for that.

    But I will say this, the stock truck/van injectors are not big enough for a cammed 6.0 above like 5,000-5,500rpm at full throttle, you'll run out of headroom there. It will be fine for now to atleast get it running but you'll later see that the injector duty cycle will be pushing 90% pretty easy.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  3. #3
    Potential Tuner
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    Cool quick response, thanks.
    I went with the AEM wideband.
    And as for running with a complete exhaust...crap. I'm currently running with I think 18" slip on turndowns on the headers. F'n loud. I guess I'll shop for some exhaust after the holiday weekend...

    I got a Walboro 450 (spelling?) in tank fuel pump for now, and I did read that the stock injectors wont be sufficient for heavy foot action. Kinda expected it but was hoping i could get by for now. I will look to go bigger that will hopefully also be suitable for a turbo upgrade...

    Thanks