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DAM Drop While Drifting in the Snow


Yasha
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I've got an 05 Outback XT running wrx up pipe and have the first CAT gutted in the downpipe. I am running the COBB acn91 stage 2 tune but only run 93, I'm trying my best to keep this baby alive. My problem is that around every 3rd time I go drifting in the snow my DAM will drop all the way down to 0.1, which I would call limp mode. I was wondering if this was possibly due to my intake temps rising to stupid high levels, between 80 and 100 in 20 degree weather.

 

The car does not knock for shit when doing logging. It might detect an instance of knock once in a blue moon when shifting from 3rd to 4th but that is just the computer being stupid. I try to stay below 5k rpm when drifting. Most of the time I sit somewhere between 3k and 4k in 2nd gear doing figure eights and other drifting shenanigans.

 

Any ideas on why the computer might be thinking my car is going to blow? I am really leaning towards either the high intake temps or boost spikes but according to the access port, the car doesn't go above like 5 psi when drifting, which I think is due to the wheels not giving enough resistance to build boost in the snow. Boost levels are totally fine when logging. and DAM is always at 1.

Edited by Yasha
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The primary cat is gutted. The primary cat is the most restrictive. There was a study made by greddy I think where gutting the first cat increased flow by 50% vs stock. Still not as good as aftermarket but definitely an improvement. Main reason for gutting the cat was so I could in fact run stage 2. At first I was not going to gut the cat. I did the uppipe as a reliability mod, to prevent the stock cat from disenegrating into my turbo. I did some logging with rom raider and a vag com and found the car knocking hella. So I bought a v2 accessport used and through on the stage 1 tune. Car was still knocking hella. I then decided to go to stage 2 but I knew that a higher flowing down pipe was required. I gutted the down pipe put the cobb stage 2 tune and no knocking. I am all about reliability not blowing shit up.
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You need a new retune to fix that, your definitely knocking. Snow lets you hit parts of the map that is probably not so fine tuned (high rpm low load).

 

Also relative4 is not wrong, stock gutted downpipe wont flow as well as a proper 3" or even 2.5" downpipe. That means more exhaust back pressure and more sensitivity to too much timing.

05 LGT 16G 14psi 290whp/30mpg

12 OBP Stock 130whp/27mpg@87 Oct

00 G20t GT28r 10psi 250whp/36mpg

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Hmmm, the high rpm, low load argument definitely makes sense. I would think not enough fuel then, right? I will retard the timing 5 degrees through the accessport and see if it knocks next time. The car was showing knock while drifting, I just didn't attribute it to actual knocking because the car never knocks while doing pulls and aggressive driving. Stupid me for thinking everything was fine. Hopefully I do not need a retune and retarding timing is enough. I should've taken advantage of the black friday sale at brentuning and gotten a dyno tune for $300.
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You can add all the fuel in the world and it will still knock if you're over advanced.

 

I find these engines don't like much timing below 4k rpm, mostly because of high AVCS (even 10*) and crappy flowing stock manifolds/turbos. Even with a big 16g with 8cm housing, going from EL header to stock UEL required me to drop a lot of partial throttle timing to prevent knock in transient low boost sections of the map.

05 LGT 16G 14psi 290whp/30mpg

12 OBP Stock 130whp/27mpg@87 Oct

00 G20t GT28r 10psi 250whp/36mpg

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Very interesting. I would have never thought that a small load could cause more knock than a big load.

 

It doesn't if the car is properly tuned, this is how silly myths start. I can make my car knock to death at idle if I run too much timing :lol:.

 

Should I then try and stay between 4k and 5k instead?

 

No, you should get it properly tuned. Even a $150 etune is worth it, considering that a used replacement engine is $3,000.

05 LGT 16G 14psi 290whp/30mpg

12 OBP Stock 130whp/27mpg@87 Oct

00 G20t GT28r 10psi 250whp/36mpg

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