Cobb AP: Bucking symptom of Detonation?
Thread Starter
Registered User
Joined: Apr 2003
Posts: 257
From: Arcadia, CA
Car Info: 2003 GGA
Cobb AP: Bucking symptom of Detonation?
Hey All,
In need of a lil' info.
I'm running Cobb AP Stage 1 HWG on my 03 Wagon.
HWG increases the wastegate duty cycles in order to increase boost. I wasn't reaching the target 14.5 +/-.5PSI until I used this map.
The problem is that I'm experiencing bucking in 2nd gear at around 4000rpm. Its brief but alarming.
My question is: Is the bucking a symptom of something harmful like detonation?
TIA for any input :P
In need of a lil' info.
I'm running Cobb AP Stage 1 HWG on my 03 Wagon.
HWG increases the wastegate duty cycles in order to increase boost. I wasn't reaching the target 14.5 +/-.5PSI until I used this map.
The problem is that I'm experiencing bucking in 2nd gear at around 4000rpm. Its brief but alarming.
My question is: Is the bucking a symptom of something harmful like detonation?
TIA for any input :P
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Bucking could be the ECU not being able to handle the fuel load. My 02 wagon bucked like a bronco if I got on the boost during the drive from my house (where I put in VF30/pinks/fuel pump/rails) and my tuner's shop. Once the reflash was done, all was well again.
It's possible your map has some incorrect fueling right where you are getting the bucking.
It's possible your map has some incorrect fueling right where you are getting the bucking.
Thread Starter
Registered User
Joined: Apr 2003
Posts: 257
From: Arcadia, CA
Car Info: 2003 GGA
Sorry for the late reply, I was on vacation last week.
I've been changing the maps to the stage1 CA 91oct and back to stage1 HWG and now the bucking has seemed to have vanished. Who knows? Maybe it has something to do with the ECU learning.
All I know is the stage1 HWG map is the only one that provides a palpable increase in performance. Guess my wastegate is a lil looser than others'.
I've been changing the maps to the stage1 CA 91oct and back to stage1 HWG and now the bucking has seemed to have vanished. Who knows? Maybe it has something to do with the ECU learning.
All I know is the stage1 HWG map is the only one that provides a palpable increase in performance. Guess my wastegate is a lil looser than others'.
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It sounds like the ECU encountered knock in a certain spot and pulled timing. When you switched maps, you reset all ECU learning, so the problem went away. If the cause of the knock was some sort of glitch or a bad tank of gas, you should be ok, but if there is an issue that is persistantly causing knock in that region, the ECU will re-learn the behaviour.
Thread Starter
Registered User
Joined: Apr 2003
Posts: 257
From: Arcadia, CA
Car Info: 2003 GGA
Originally Posted by EQ Tuning
It sounds like the ECU encountered knock in a certain spot and pulled timing. When you switched maps, you reset all ECU learning, so the problem went away. If the cause of the knock was some sort of glitch or a bad tank of gas, you should be ok, but if there is an issue that is persistantly causing knock in that region, the ECU will re-learn the behaviour.
What I need is for Cobb to put out a stg1 CA 91oct HWG map. They have one for the STI but not WRX.
Looks like I'll have to request one.
So my next question would be: How much harm am I doing to my engine if the ECU is detecting knock and pulling the timing?
Last edited by Clint Torres; Jun 8, 2005 at 03:46 PM.
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