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ej205 swap impreza wrx feed back knock; is it real or just ghosts?

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hello all,

I have been starting off in my efi tuning with a fun thing! knock! I have a speculations about what it could be after some tuning trials and I want to think maybe somewhere in the maf calibrations that its wanting 2.5L when I have a high compression 2.0 . I want to believe maybe that since the displacement is 1994cc in my current engine when the previous engine was 2457cc, my only backing of this is when I wot 100% knock feedback is at 3.0 and if I ease through the throttle I see 1.5-2.5 depending on atmosphere variables. the only other thing I can think of is maybe somewhere in the intake I have a leak like on the coupler between the tmic and the throttle body. also good to mention I have checked over timing and increased fuel at no avail; as one other post script I am running stock intercooler bypass valve and intake coupler I have seen that these are prone to boost leak which is also a factor that can affect my knock feedback!

I am using hp tuners. thanks in advance

The first point that you need to consider is your MAF scaling. If this is incorrect then your entire calibration will be out. Provided you have the MAF scaled correctly and you're able to hit your AFR targets consistently then you can start looking elsewhere. The factory Subaru ECU also goes to great lengths to try and run the ECU in closed loop mode as much as possible, even up to moderate boost levels, which can result in knock. This requires you to change the closed loop compensation tables to reflect reasonable AFR targets and I set the CL/OL delay to zero. Beyond this, use audio knock detection to actually confirm if your knock is real or not.

so I have re-flashed my ecu and the knock feed back persists and with maf scaling I am going to dive more in depth into my courses and see if I can find appropriate answers before I just ask for what Is what; I did get my main ve tables to pop up they weren't before so I think maybe its causing issues cause the computer thinks its a 2.46litre engine in the bay so I'm going to do the math to find out what liters I'm dealing with in the ej205

Wouldn't the stock knock sensor calibration be centering on the bore diameter of the original 2.5lt engine which would be wrong in your 2lt?

Picking up unwanted (incorrect) noise and thinking it's knock iow?

I'd think this too with my learning on engine building from my mentor from high-school he was a pro engine builder here named Butch Stetson a real standout guy who taught me "if it isn't blueprinted somethings going to go wrong". which I have looked into my ecu but I am still fresh to ecu tuning I understand turning the timing in a distributor and re jetting carbs to make more power and how this could apply to a fuel chart and timing chart but anything knock I am lost. :/ oh and update I did as ben advised but no avail now I am possibly going to tear down the intake as I have done a tgv delete not too long ago and I'm going to check for any gremlins that I may have overlooked as well as replace a pesky sensor that just went out! check over my cylinder pressure and if its still around i'm more than sure its the issue with boost leak the 09 impreza wrx stock intercooler and bpv. thanks for all the help much needed

so update! I replaced my charge pipe and before while stopped and just giving it some throttle it would receive about 2.5 knock feedback where as now I have reduced it down to 1.5 with just a silicone charge pipe! imagine what a proven aftermarket top mount and bpv will do! thanks for all the help

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