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Old 10-10-2012, 11:40 AM   #8
Scooby Newbie
Member#: 293573
Join Date: Sep 2011
Location: northern california
2006 sti
OBP on Meth


Originally Posted by ARiSTA Performance View Post
As weird as this is going to sound, check your coolant reservoir for your turbo and radiator. If they are low or empty, top them off with 50/50 coolant. From my understanding when the coolant is low, the DAM of your car will drop below the value of 1.0 and therefore reducing the target boost level. Then reset your ECU with Cobb AP

That is what I was told to do when I had the same problem and it worked for me. Once I datalogged the car it all made sense. Datalog it and post up the file and it will narrow down some possibilities. I'd also perform a compression test to be on the safe side -$30 kit from AutoZone, about 2-3 hours to do it yourself with some instructions from NASIOC/IWSTI wouldn't hurt.

ill check the coolant today, that would be an easy fix. the motor has about 10k on it from a recent rebuild

Originally Posted by ARiSTA Performance View Post
Also, when did you perform those mods and when did the problem start happening? Do you have a bigger fuel pump?

i never realized it was happening untill i hooked my ap up to see the boost on it. i noticed it wasnt pulling hard anymore so i wanted to check and see if it was just me being used to the power or if it really was lacking i have a walbro255 fuel pump, from what i can tell the afr's are good under wot

Originally Posted by FRWRX View Post
Are you tuning your car yourself ?
If when you reflash the car it seems to recover power, it's only because you have a problem with the learnings. I bet that instead of reflashing the car if you perform an ECU reset, you will recover power as well.
So it's just a bad tune, or eventually a leak somewhere.
i had my local shop do a dyno tune on it, im going to call him today a see if he has any ideas.

Originally Posted by NSFW View Post
I would almost bet that your IAM is just dropping over time. That will cause the ECU to cut your boost roughly in half.

Maybe you need higher octane fuel, or maybe your tune is just too aggressive for the fuel that you have.
ill look into the fuel but i only run shell or 76 91octane would octane booster help or would i need to mix in race gas?

Originally Posted by k mier View Post
My $.02, the ecu is learning, it sees something it doesn't like and is pulling power to be safe. Could be knock form different fuel, heat, aggressive tune, etc. Data log.
what things should i data log to get good info?
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