|
|
|
|
Thread Tools | Display Modes |
02-27-2007, 02:32 PM | #1 |
Scooby Newbie
Member#: 118697
Join Date: Jun 2006
Chapter/Region:
TXIC
Location: Mcallen, TX
Vehicle:2002 WRX WRB |
Actual Timing
Folks,
Last night I datalogged my stg 2 tune (cobb stg 2 93 octane) and the actual timing was quite a bit less (~3-6 degrees) than maximum map +KC values. (Yes my IAM was at 16!) Then I was worried so I reflashed the to the stock map, but actual timing there was still 3 degrees less. I may have a boost leak, so perhaps that would account for it (and becoming worse with a higher boost map). Or is it common for the subie 2002 wrx ecu to pull timing for other concerns besides knock, intake temp. and coolant temp? -Cory
* Registered users of the site do not see these ads.
|
02-27-2007, 03:01 PM | #2 |
Scooby Newbie
Member#: 115260
Join Date: May 2006
Chapter/Region:
MAIC
Location: Dover, DE
Vehicle:04 WRX 205/22E Hybrid w/ VF39 |
Are you logging the actual KC value? IS it lower than your mapped value, or are you seeing your full mapped KC and still a couple degree's short?
If so, check out this thread from enginuity.org. |
02-27-2007, 03:40 PM | #3 |
Scooby Newbie
Member#: 115771
Join Date: May 2006
Chapter/Region:
NWIC
Location: Spokane WA
Vehicle:2006 WRX WAGON OS Stage 1 |
Look at the kc value the map calls for and when you log it look at the actual kc value to see if it pulled timing.
|
02-27-2007, 06:47 PM | #4 |
Scooby Newbie
Member#: 100767
Join Date: Nov 2005
Location: Miami, FL
Vehicle:2013 STI Blurple |
Log KC values, probably light knocking.
|
02-27-2007, 11:12 PM | #5 |
Scooby Specialist
Member#: 44422
Join Date: Sep 2003
Chapter/Region:
SWIC
Location: Gilbert, AZ
Vehicle:2009 G8 GT Cammed, sprayed, stalled |
Could also be timing reduction due to coolant temp over 194F or intake air below 50F. There are more reasons why the ECU pulls timing than simply knock.
|
02-28-2007, 12:11 AM | #6 |
Scooby Newbie
Member#: 115771
Join Date: May 2006
Chapter/Region:
NWIC
Location: Spokane WA
Vehicle:2006 WRX WAGON OS Stage 1 |
|
03-02-2007, 10:33 PM | #7 | |
Scooby Specialist
Member#: 53665
Join Date: Jan 2004
Chapter/Region:
NESIC
Location: Northboro, MA
Vehicle:2022 BMW M240i Thundernight |
Quote:
"WRX owners with 16bit ECUs..does your timing curves line up" http://www.enginuity.org/viewtopic.php?t=1226 To save you some reading, it turns out that the timing reported by the ECU tends to be 2* off from what the maps call for on 16bit ECUs. I did notice this on my 04 WRX when I analyzed my logs. I did not see any knock reported but the timing did seem to be missing 2 degrees of timing even when things seemed to be knock free. Investigation revealed that there is a per cylinder compensation map that pulls 2* out of two of the 4 cylinders. It just so happens that the knock sensor is located on the side of the engine where cylinders 2 and 4 reside. In engine failure cases, those are usually the ones that fail first. Older JDM STIs used to run with different heat range spark plugs on those 2 cylinders to accommodate the variance between the cylinders. Everything suggests that Subaru instituted the compensation map to account for the inherent tendency of those 2 cylinders to detonate sooner than the other 2. It is also interesting to note that those 2 cylinders have the longest exhaust paths which produces more back pressure, raises EGTs, etc. It looks like the ECU reports the timing based on the timing of one of the 2 cylinders that gets that 2* pull so that is why your logs will show 2 degrees less than what your base + KC maps will call for, given you get no knock. If you see more timing pulled and KC dropping, you could be seeing knock. Turbo_Mike experimented with a custom image where he removed the timing compensation and his ignition timing did line up with the logs so looks like the mystery has been solved. Last edited by Ziggyrama; 03-03-2007 at 09:28 AM. Reason: Added some extra info in there |
|
03-04-2007, 03:45 AM | #8 |
Scooby Specialist
Member#: 16827
Join Date: Mar 2002
Chapter/Region:
SCIC
Location: Southern California: Orange Co
Vehicle:2003 WRX(Sold), Z4 Aspen White |
^^ great info, thanks zig
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
If you need new HVAC -- now's not a bad time to buy | jpicheva | Off-Topic | 32 | 06-04-2010 10:06 AM |
Huh. That was actually quite horrible. | UberWilhelm | Off-Topic | 40 | 06-03-2010 12:26 PM |
clutch going, what is the actual time to... | Darryl | Transmission (AT/MT) & Driveline | 6 | 10-27-2008 08:24 PM |
So last night I was actually TERRIFIED for the first time in my life... | GooseMan | Off-Topic | 27 | 11-07-2003 02:43 PM |
Anyone actually time Stage 1 Cobb cams + turbo? | Rich L | Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) | 6 | 04-06-2001 04:38 AM |