I own a 2015 Subaru STI. The car was stock when I bought it. These are the first modifications it has seen.
I have been having issues with my DAM dropping below 1. My knock feedback and fine knock learn have also been showing concerning readings (more than -2.8). About once per month I have to reflash my tune because the DAM drops to 0.8xx. It always happens when I am ripping on her. I currently have a Cobb Intake with a Cobb Stage 1+SF 93 Tune. I have a Grimspeed Air/Oil Seperator as well. I need feedback from experienced tuners/Subaru Enthusiast. I have a few data logs attached.
Other than the concerning guage readings, I briefly looked over my datalogs and noticed that peak boost was around 16.8psi when it is normally around 19psi? I have not done a leakdown test in a while. Also, the car seems to stall/hesitate more than it should between shifts. I can over come this by "riding the clutch" more than usual but it makes me nervous because I've driven other STI's like mine and that hesitation is not there. This hesitation was present when the car was also bone stock
DAM dropping during WOT or hard driving is never good.
Do not reset your ECU when your DAM drops. DAM is designed to protect the engine in case something is wrong. Resetting the ECU is a bandaid, and you need to figure out the original problem.
If this were me, I'd flash the cobb Stage 1 SF+ with 91 map and run 93. it sounds like you are getting knock and the ECU is compensating by pulling timing(as it should).
So I took your guys advice and re-tuned the car to Cobb Stage 1+ SF 91 while still running 93 octane. I notice the car has been running better (more smooth) less hesitation between shifts/smoother pulls and boosting. The hesitation between shifts is still there but less intense. I also notice that my Fine Knock Learn and Fine Knock Feedback is back within tolerable levels. However, today on my way home I watched the these value change and hold during WOT on the freeway. This freaked me out so I started logging as soon as I got off and gave her a balls out pull from 3rd to 6th.
I have two data logs attached. One is with 93 tune and the other is with 91 tune. Again, I notice that the boost logged is around high 16lbs when my stock boost guage is reading 2lbs higher? I also noticed after my WOT pull I could smell some oil?! This made me think that maybe i'm getting too much blow by from my Grimspeed AOS and need to upgrade? My turbo is stock and only a stage 1 OTS Cobb Tune so I wasn't that worried about crankcase pressure until now?
Mine was also the street AOS. but im running E85 and didn't want to deal with the smell
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