Join Date: Mar 2011
Location: New Jersey
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I would be a bit worried about the feedback knock correction, especially if it doesn't find it's way back to zero quickly. Fine knock isn't good either. They should both be at zero on a full throttle pull on a smooth surface.
Check out this video that Cobb put together. It will tell you what to look for when logging and what's acceptable and unacceptable. You may need a little more learning time with regular driving. You could give it a few days of regular driving and then do a few more logs at full boost. If you still see the knock correction you will need to get a hold of tuner. I'd call him soon to tell him about the knock you're seeing.
cobbtuning's Channel - YouTube
I don't have a whole lot of experience tuning. I just starting working with a friend on his built E85 EVO. He's been tuning using open source and we did a couple of pulls and he showed me a few things to look for. I only logged my car to make sure nothing was wrong and my logs showed 0's for the whole run in the Fine knock and feedback knock correction.
Here's my log. I hope this helps.
^If you want to send me the log in excel I can run an airboy for ya......
Always fun to compare #'s.
And yeah, you should see no knock correction of any kind. If you are, you're knocking. The amount of correction is really irrellevant, it's pulling timing because you're knocking. There really isn't any variation in the level of knock IMO (aka no knock is more or less severe than another knock, it's all knock aka exploding rather than burning fuel), the ECU just pulls different amount of timing until it figures out exactly how much it needs to pull out.
That's also why you're seeing the values for correction drop after the first log... The car may be able to pull timing out until it doesn't see any, but then it will start to add it back in until it knocks again, then back down, then back up again.... You get the point. It's best to set the timing lower than the knock threshold so the ecu can never put the car back into the range on its own.
Both logs are pretty consistent in showing that the ECU is pulling timing back from 15 when the knock correction comes in. So to me, it looks like too much timing or too much boost. I didn't see boost on your graphs. I'm assuming 21 like you said was your target, and that is a lot of boost. I've seen some tuners make more power with less boost and more timing. You just have to find the sweet spot.
I knew a guy who knew a guy that dropped forged pistons in and got phantom knock, or at least he thought it was. It cost him his built motor and now he's on number two.
You can sign up for a free Google Docs account (if you don't have gmail already) and upload your excel spreadsheet like I did. It's a little easier to read that way.
The next time you log you can reset the monitors to the defaults like was suggested in the video, then add A/F ratio.
You can download virtual dyno and drop your log in there. It's pretty cool and free. It will give you your horsepower reading.
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