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Discussion Starter · #1 ·
So today I finally picked up my Cobb AP for my 2018 WRX and love it already. What gauges do you all recommend I use? There is atleast 50+ to choose from and i have no clue what 99% of them mean. I just want the best ones that help me monitor the car and stuff.
 

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https://cobbtuning.atlassian.net/wiki/spaces/PRS/pages/71991590/How+To+Datalog+Subaru+Vehicles

This is a pretty good link reviewing some of the more "useful" data you might want to use in logging. Also, it has some good information to educate yourself as to what everything means. (General terms) I personally use DAM, Fine knock learn, Feedback knock, AF ratio, TD boost error, Boost.

When actually doing a pull, and recording data, I would also add AF learning for the log. As for the gauges, the ones above should give you somewhat accurate diagnosis of problems/error
 

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Did you read ANYTHING in the link that I posted? That pretty much gives you all the info you need. Or at least a starting point. AFR all depends on the OTS map you're running but at idle somewhere around 14 ish. DAM should be around 1. You don't want to see any FK or Feedback knock when WOT, however at cruising it's expected. -1.41/-2.82 are the value's you wouldn't want to see when WOT.

This is as general as it can get.
 

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Discussion Starter · #8 ·
Maybe it wasn’t WOT, I just had a spirited drive home from work today and noticed it had a low value of -1.41 when I got home, could of just been cruising when that happened.
 

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Captain James of the SS Impreza has gone down with
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Maybe it wasn’t WOT, I just had a spirited drive home from work today and noticed it had a low value of -1.41 when I got home, could of just been cruising when that happened.
Did your DAM drop at all? DAM is slightly more important and you want it to always have a value of 1.
 

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Discussion Starter · #11 ·
Kept an eye on feedback knock and the odd time it will goto -1.41 then back to 0. Ussualy would happen 1st gear when Im below 2500rpm or 2nd gear when I’m going like 1500 just going through a parking lot. No feedback knock at WOT and never fine knock. Other concern tho is my AFR goes lower then -8 but it’s at idle. WOT it’s ussualy zero, is there a issue there.
 

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Discussion Starter · #14 ·
One other thing, I have been getting fine knock learning now and it will read -9.84 and it happens when I downshift, mainly from 4 to 3 and also happens when I start going in 1st gear
 

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my 18 wrx gets plenty of random knock and even some fine knock learn here and there. dam has dropped a few times now and recovered back to 1. i think, as cobb mentions, that our cars are just designed to be cautious with knock, and as such we get a lot of false positives. witch due to coincidence, will occasionally add up to the car thinking a real knock event has taken place and drop the dam and await further data before restoring full power.

or our cars could just be knocking like crazy and were doomed, its a new engine and there is really no way to know for sure, just trust that Subaru isn't selling lemons to a known tuner community who will willingly and often mod their cars and void their powertrain warranties.
 

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-1.41 on the feedback knock is considered normal in highway cruising, cruising, or any time you are low rpms/high load (which you should avoid). However, any knock at WOT is typically not good. BUT, the knock sensor in these cars is pretty sensitive and can detect a false knock from other vibrations and stuff normally.

Fine knock learn is when your ecu has recognized a knock event happen in the same rpm/load on several occasions. At this point your ecu will automatically pull time in that range to prevent detonation (fine knock learning), and is normal. Although it is pulling a significant amount more timing than what you are saying your maximum feedback knock correction is.

I will add that a custom tune will clean up some of the knock, whether it be false knock or actual knock. Cobbs OTS maps are not the greatest, but considered to be safe for most vehicles to use. My STi got random crazy knock events when running the cobb stage 2 map. I added a lot of mods and got protuned and I rarely see knock now. Less than 5 events of knock since I have been protuned. And that was in early April. I used to see feedback knock correction daily on cobbs map.
 
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