Reading the Dyno Chart
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This is a discussion on Reading the Dyno Chart within the Engine Modifications forums, part of the Tech & Modifying & General Repairs category; I recently had a re-tune for my 2008 WRX gh. It's the first time, so I need help in reading ...

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    Reading the Dyno Chart

    I recently had a re-tune for my 2008 WRX gh.
    It's the first time, so I need help in reading the dyno chart.

    I'm happy with increase. It feels like driving a totally different car.

    I'm not too familiar with how to read the dyno chart, though, especially the chart at the bottom. I think that's the AFR chart? (blue is baseline, red is after tuning).

    I just have a 3" bellmouth catless downpipe, HKS legamax premium midpipe and muffler.
    Everything else is stock.

    Are those numbers good/bad?



    TIA for helping a newbie out.
    Last edited by sugeina; 04-03-2014 at 09:51 AM. Reason: added mods

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    Moderator Donkey's Avatar
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    You have what mods done?
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    Oh yeah.
    I just have a 3" bellmouth catless downpipe, HKS legamax premium midpipe and muffler.
    Everything else is stock.

    (edited original post)
    Last edited by sugeina; 03-30-2014 at 08:09 AM.

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    I confirmed that that chart is the AFR chart.

    So, that means i'm running in the lean (~15) from 2.75k to 3.8k rpms, after which it starts to go rich ~11-12 until redline. Is this good?

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    Quote Originally Posted by sugeina View Post
    I confirmed that that chart is the AFR chart.

    So, that means i'm running in the lean (~15) from 2.75k to 3.8k rpms, after which it starts to go rich ~11-12 until redline. Is this good?
    The way I am reading that chart is by 5500 you are at a 10:1 AFR and by 6500 rpm you are at about a 9:1 AFR. A little rich for me. I generally target around a 11.5-11:1 at redline. What was peak target boost?
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    Master Baiter EJ257's Avatar
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    Looks like a boost plot to me...
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    Quote Originally Posted by EJ257 View Post
    Looks like a boost plot to me...
    Agreed. That's exactly what it looks like to me... typical boost curve for a 2.5L running a TD04-19T 16 PSI peak tapering to 8 PSI by redline.
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    i posted the other print out i got.
    some others also told me it looks more like a boost plot, than the afr chart...

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    Master Baiter EJ257's Avatar
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    Quote Originally Posted by sugeina
    i posted the other print out i got.
    some others also told me it looks more like a boost plot, than the afr chart...
    It's the same plot...you just have the one run in the other graph.
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    Quote Originally Posted by EJ257 View Post
    Looks like a boost plot to me...
    Quote Originally Posted by zax View Post
    Agreed. That's exactly what it looks like to me... typical boost curve for a 2.5L running a TD04-19T 16 PSI peak tapering to 8 PSI by redline.
    I hope that these guys are right. That is a pretty rich AFR. I would double check again with your tuner.
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    Master Baiter EJ257's Avatar
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    Quote Originally Posted by Donkey
    I hope that these guys are right. That is a pretty rich AFR. I would double check again with your tuner.
    Tuner is the one who can confirm, but does it not look like a boost plot to you?
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    Quote Originally Posted by EJ257 View Post
    Tuner is the one who can confirm, but does it not look like a boost plot to you?
    It does indeed.
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    you guys are cool. it IS the boost plot.
    i checked the other chart, and there's a faint line at the bottom graph. that IS the afr graph.

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