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1 count of knock pulls timing?

fastasleep

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Joined
Jan 14, 2005
Messages
1,779
Location
Christiansburg, VA
RPM TPS KNCK TIMA O2 INJP
3000 100.0% 0 26° 0.80V 11.52ms
3188 100.0% 0 20° 0.82V 15.10ms
3406 100.0% 0 16° 0.82V 15.62ms
3594 100.0% 0 16° 0.82V 15.62ms
3813 100.0% 0 16° 0.84V 16.38ms
4094 100.0% 1 16° 0.84V 16.90ms
4219 100.0% 0 15° 0.84V 17.41ms
4469 100.0% 0 18° 0.84V 17.92ms
4688 100.0% 0 18° 0.86V 18.43ms
4906 100.0% 0 19° 0.86V 18.43ms
5188 100.0% 0 19° 0.86V 18.69ms
5375 100.0% 0 20° 0.86V 18.94ms
5563 100.0% 0 21° 0.86V 18.94ms
5719 100.0% 0 22° 0.86V 18.94ms
5875 100.0% 0 23° 0.86V 18.94ms
6031 100.0% 0 23° 0.86V 18.94ms
6125 100.0% 0 24° 0.88V 18.69ms
6344 100.0% 0 24° 0.88V 18.43ms
6344 100.0% 0 25° 0.88V 18.18ms
6563 100.0% 0 25° 0.88V 17.92ms
6656 100.0% 0 25° 0.88V 17.41ms
6688 39.6% 0 23° 0.88V 1.28ms


16*, 15*, 18* why?
 

gvr4ever

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Joined
Aug 6, 2002
Messages
6,190
Location
central Indiana
3 counts and below, and your ECU should advance your timming. http://hywell.org/plhelp/data.html

Your 02s look a tad low for pump gas. It should be closer to 0.90v to 0.92v.

If INJP is injector duty cycle then nothing really looks bad, but they seem all over the place if you were running WOT at the time. Looks like you were. I'm not going to pretend for one moment to be a logger expert. I'm using pocketlogger for dummies /ubbthreads/images/graemlins/smile.gif 20ms on the injectors is 100% duty cycle.

You might want to check your base timming and make sure you don't have any slack in your throttle cable. How old are your injectors and how old is your 02 sensor?
 

fastasleep

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Jan 14, 2005
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Location
Christiansburg, VA
INJP is injector pulse width, not duty cycle. I calculated IDC with this site. Duty cycles are looking high above 5500rpm (obviously). Rewired stock pump, stock 450s (70k mi, I assume theyre the originals). My boost gauge says that at wot, Im at 14psi creeping to 16psi up top, but I have reason to believe my gauge is reading 3psi too high, so I think I'm really running 11psi creeping to 13psi (14b with my hallman zero'd out). Either way, I should have the Prosport boost gauge at the end of this week so I'll know for sure then. I was just curious about the odd timing right there. I'll see if I can check base timing with my friends timing light sometime this week.

edit: oops, forgot to post the duty cycle log...

RPM TPS KNCK TIMA O2 IDC
3000 100.0% 0 26° 0.80V 28.80%
3188 100.0% 0 20° 0.82V 40.12%
3406 100.0% 0 16° 0.82V 44.33%
3594 100.0% 0 16° 0.82V 46.78%
3813 100.0% 0 16° 0.84V 52.05%
4094 100.0% 1 16° 0.84V 57.66%
4219 100.0% 0 15° 0.84V 61.21%
4469 100.0% 0 18° 0.84V 66.74%
4688 100.0% 0 18° 0.86V 72.00%
4906 100.0% 0 19° 0.86V 75.35%
5188 100.0% 0 19° 0.86V 80.8%
5375 100.0% 0 20° 0.86V 84.84%
5563 100.0% 0 21° 0.86V 87.80%
5719 100.0% 0 22° 0.86V 90.26%
5875 100.0% 0 23° 0.86V 92.73%
6031 100.0% 0 23° 0.86V 95.19%
6125 100.0% 0 24° 0.88V 95.40%
6344 100.0% 0 24° 0.88V 97.43%
6344 100.0% 0 25° 0.88V 96.11%
6563 100.0% 0 25° 0.88V 98.01%
6656 100.0% 0 25° 0.88V 96.57%
6688 39.6% 0 23° 0.88V 07.13%
 
Last edited:

gvr4ever

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Aug 6, 2002
Messages
6,190
Location
central Indiana
Digital tunning says the same thing about

knock

Looking back at the log, the timming advance seems a little high for WOT. How is this car tunned?
 

Hertz

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Jul 29, 2002
Messages
13,501
Location
Chicago, IL
I have never seen evidence of the ECU increasing timing if there is 0-3 knock. Even moreso, I cannot believe that advancing the timing would decrease predetonation. I'm confused.
 

teet

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Joined
Mar 8, 2001
Messages
1,245
Location
northwest
that's not pulled. thats "normal" for the factory ECU assuming you're "high" in the airflow range the ECU is seeing.

the ECU is mapped to pull timing at the torque peak (around 4-4.5k) and then will bump timing back up as RPMs rise.

I see nothing wrong with that timing curve.

timing should NOT be flat through the RPM range.
 

fastasleep

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Location
Christiansburg, VA
The car has no tuning. Thats stock timing advance. So its all good?
 

Hopefully Jeff or somebody of ecu authority will jump in here to confirm. But my understanding and experience is that the ecu pulls 1 degree of timing for every ~2.8 knock counts.
 

gvr4ever

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Messages
6,190
Location
central Indiana
Quote:
I have never seen evidence of the ECU increasing timing if there is 0-3 knock. Even moreso, I cannot believe that advancing the timing would decrease predetonation. I'm confused.



Maybe the programers of the software wanted to give some room for false knock. The knock sensor is pretty touchy. If you can't trust digital tunning, who can you trust?

Keydiver would be the only other source I would trust in this matter.

I'm confused as to why the logs WOT timming is so high acually. You want at least and more then 15 degree's at WOT, but 25?!?! With a stock ECU? I think this guy needs to check his base timming and see where it is at. Something seems out of wack, or I'm not reading something right.
 

steve

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Sep 11, 2003
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NJ
It looks like timing is advancing as he moves up the RPM range, just like its supposed to. /ubbthreads/images/graemlins/confused.gif
 

Hertz

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Chicago, IL
Quote:
I'm confused as to why the logs WOT timming is so high acually. You want at least and more then 15 degree's at WOT, but 25?!?! With a stock ECU? I think this guy needs to check his base timming and see where it is at. Something seems out of wack, or I'm not reading something right.



The logger doesn't know if the base timing is actually set at 5 deg BTDC. There's nothing wrong with advance if you're not knocking. /ubbthreads/images/graemlins/smile.gif
 

powerplay

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Jul 24, 2004
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Location
Norwell, MA
Here is the timing map for our car. It is based on load vs RPM as you can see. The numbers represent degrees of timing.
 

Hey everyone, just signed up again, not sure what happened to my account, maybe I was inactive for too long or something. Glad to see everyone hasn't gotten an evo yet. 1416/2000 is still alive, but in fair shape at best. I hope to give her some love this summer though.

Anyway, this seemed like the perfect thread to post my first post in /ubbthreads/images/graemlins/devil.gif I believe I have seen evidence of 1 count of knock decrease, or at least halt, timing advance. I am not any expert, but I have logged my car a lot, and I have always said any knock sum above zero will effect timing advance. I got tired of messing with knock/ /ubbthreads/images/graemlins/banghead.gif phantomknock all together and got a keydiver chip set to ignore knock while not under boost. Problem solved /ubbthreads/images/graemlins/grin.gif I will try to find some of my old logs (new PC) showing 1 knock sum lowering timing advance. If I can't find them I might even pop in the stock EEPROM and make some new ones.

My 2 cents.
 

stealthtt24

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May 24, 2005
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Location
Orlando, FL
Quote:
Here is the timing map for our car. It is based on load vs RPM as you can see. The numbers represent degrees of timing.




what do those numbers represent,1-12, at the top of the graph?
 

Hertz

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Messages
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Chicago, IL
In pocketlogger it's called "Air Volume", a calculated number based on a Air Flow, Barometer, and Intake Temperature.
 

Quote:
Hopefully Jeff or somebody of ecu authority will jump in here to confirm. But my understanding and experience is that the ecu pulls 1 degree of timing for every ~2.8 knock counts.



Well, actually, the knock/timing thing is a little more complicated than that. I've never been able to find anything in the code to support the often quoted "below X knock timing goes up, between X and X it holds, and above X timing gets pulled". Instead, there IS code similar to that which affects the "octane value", a long term timing trim, which starts at 255, but gets decremented by 1 if the knock goes above 5, remains the same if knock is between 3 and 5, and will be incremented by one if the knock is
 

Quote:
Here is the timing map for our car. It is based on load vs RPM as you can see. The numbers represent degrees of timing.




Actually, those rpm row numbers are wrong. First, I'll admit that they are mine, from some early guesses I made, which were close, but not exact. The actual rpm's for each of the rows are: 750, 1000, 1250, 1500, 1750, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000.
So, to me it appears that, in his logs, the ECU is only seeing enough airflow to get him up to about the 11th column, which would be ~10 lbs of boost. Either he's running low boost, or lying to the ECU about the actual airflow.
 

Jeff hath spoken... /ubbthreads/images/graemlins/worthy.gif

No knock is good knock.
 

AT LAST! The origin of the fameous "knock sum below 3 advances timing, above retards..." myth. If I read keydiver's post correctly thats true (sort of) for long term timing. But only up to the no-knock (full octane) values in the "primary" timing map. I can see how this got mis-interpreted.

Nice to have a REAL guru (and one too humble to admit to the title) on this site. Thanks Jeff.
 
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