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Acceptable KR, stock PCM, L36

Sabrewings

Sabrewings

New member
I got my Aeroforce put in today, and started some scanning. I know we strive for 0* of KR, but what is acceptable.

I have a catback, WizAired, 2.5" DP, and 180* T-stat on the stock PCM (took the ZZP out because of how my tranny was acting) for the L36. I see 0 KR most of the time, at 1/3-1/2 throttle I get maybe 0.5* KR. But, at WOT, I see as much as 10* of KR.

Acceptable for the L36?
 


10* is by far from acceptable. When crusing or when i stab the throttle real quick i usually dont worry about any kr as long as it is not over 2*. I wouldnt know what to tell you to look for (someone else chime in) but i would say you have some sort of mechanicale problems.Lots of times you will have kr from the factory but 10* seems like a lot.



Wot I tune for 0 kr.That is the only thing acceptable to me at wot.


I belive for every * of kr that is present you lose 2.5 hp
 
Geez thats a lot of KR. Can you verify with someone elses scanner that those numbers are correct? Acceptable to me is 0 although I live with less than 1.
 
IndeedSS said:
Geez thats a lot of KR. Can you verify with someone elses scanner that those numbers are correct? Acceptable to me is 0 although I live with less than 1.
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It was mentioned that with my mods the stock PCM is running it lean. I'm going to monitor the LTFTs tonight and see what I get.
 


JCG's-GTP said:
Not to thread jack ya.. but my ZZP PCM shifts odd too. Interesting
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There is a thread around here some where( I think in the overkill performance section for community vendors) asking about this or letting overkill know if he was aware of the problem...I think it turned out to be something with the line pressure being at 96 witch is to high for the 04+ models...check it out it's somewhere around here.
 
Okay, good news. It's not as bad as I thought. I may have had the values set up wrong earlier and I went through the whole setup process making sure I only had the values enabled that I needed. That way I didn't have something similar that was confusing it (like Knock 1, 2, and 3. only need knock 1 for our cars).

Anyway, I went out and recorded a few WOT runs with the gauge's own record feature. During normal driving, my LTFTs are usually negative (whatever that means) and between -1 and -3. Rarely do I see them positive.

During WOT, I saw the LTFTs go immediately to 0.0 and the knock was only 1-2*. After the 1->2 shift, it spikes to 6.7* and starts dropping back to around 1-2* all the way to the 2->3 shift. This is with the stock PCM, BTW.

These seem like much more acceptable numbers to me. :)

Thoughts from the tuning experts?
 
As for the ltft and stft's that is good if they lock in at zero at wot....When they are showing numbers like -3 or +3 that means the pcm is pulling or adding fuel to that particular cell (bad). You dont want to have the pcm making corrections for anything like that.but the only way to fix this is with a tuner and a mass airflow tune.


1-2 degrees...may be acceptable to some. 6.7...no where near acceptable to any.

As far as the problem with the spike in kr after the upshift.That caused by anything from torque management to false knock.But again you would need a tuner to do some tests to tell anything further.


With your 6.7* of kr cosider all of the hp gained from all of you mods gone.
 
TDCRacing said:
With your 6.7* of kr cosider all of the hp gained from all of you mods gone.
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That is only there for a split second (a couple frames on the Interceptor gauge) and instantly begins dropping. It starts during the shift and starts to drop as soon as the shift completes. I think it does have to do with torque management, based on the timing.\

I'm obviously not going lean, since the LTFTs are zero. And its the stock PCM, so I'm not running any significantly advanced timing.
 
Sabrewings said:
That is only there for a split second (a couple frames on the Interceptor gauge) and instantly begins dropping. It starts during the shift and starts to drop as soon as the shift completes. I think it does have to do with torque management, based on the timing.\

I'm obviously not going lean, since the LTFTs are zero. And its the stock PCM, so I'm not running any significantly advanced timing.
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From what you just described about it dropping imeaditly after the shift I would also have to agree on the TM. altering the knock retard decay rate would help you out in this case as well as disabling th TM or at least reducing it some.Hey you should put the zzp pcm back in and see where your kr is at.

Where are you're o2's at wot?
 


TDCRacing said:
Hey you should put the zzp pcm back in and see where your kr is at.
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Not so sure I want to with what it was doing to my tranny. Hard shifts, occasional slippage, etc. It's just fine with the stock PCM, so it's their tune on 04+ tranny's doing it.

TDCRacing said:
Where are you're o2's at wot?
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I take it you're looking for their reading, in millivolts right? I'd have to get back to you, since the Aeroforce only shows me a couple values at a time. No, its no full scanner, but it has a lot of handy features and is always there. :)

(plus there's the look cool factor :th_winking: )
 
sorry dude I didnt even realize you were the one that started that thread.....I'm tired and going to sleep later:th_depressed:
 
Sabrewings said:
Not so sure I want to with what it was doing to my tranny. Hard shifts, occasional slippage, etc. It's just fine with the stock PCM, so it's their tune on 04+ tranny's doing it.



I take it you're looking for their reading, in millivolts right? I'd have to get back to you, since the Aeroforce only shows me a couple values at a time. No, its no full scanner, but it has a lot of handy features and is always there. :)

(plus there's the look cool factor :th_winking: )
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Yea i got ya....Just trying to get a better idea of if your running rich or lean...I know it's just a stock narrow band o2 sensor and is only accurate at 14.7 afr (i belive) but it can give you a good estimate anyway
 
TDCRacing said:
sorry dude I didnt even realize you were the one that started that thread.....I'm tired and going to sleep later:th_depressed:
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That's fine. It helps others. I work mids shift (military life, yay) which means 11PM to about 730AM. I'm up all night anyway as its the middle of the day for me. :th_laugh-lol2:

TDCRacing said:
Yea i got ya....Just trying to get a better idea of if your running rich or lean...I know it's just a stock narrow band o2 sensor and is only accurate at 14.7 afr (i belive) but it can give you a good estimate anyway
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I'll take a look. I was kinda hoping that since my LTFT was at 0.0 during WOT that the PCM was reading everything right on the money from the O2. Guess I still got stuff to learn. Hence why I don't have a tuner yet. :th_nervous:
 


The Interceptor gauge gives the O2's output in millivolts. Under WOT it reports 850-880 mV. Not sure how that translates into an actual O2 reading. :th_wtf:
 
Sabrewings said:
The Interceptor gauge gives the O2's output in millivolts. Under WOT it reports 850-880 mV. Not sure how that translates into an actual O2 reading. :th_wtf:
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Although the NB's arent consistant, most have found 920 to 950 the right range. My WB at 11.6:1 AFR was about .920 mV .
 
That spike in knock is more than likely false knock. Knock does not just appear at 6, it has to climb...true knock that is. If it just spikes extremely fast from 2-6 without going 3-4-5-6 then it is false knock. I would check the transmission dipstick tube and also see if your downpipe is close to your swaybar as you may have to flip it. This may be different on an impala but I do believe it is the same setup as far as a "rolling chassis" is concerned.
 
Minno said:
That spike in knock is more than likely false knock. Knock does not just appear at 6, it has to climb...true knock that is. If it just spikes extremely fast from 2-6 without going 3-4-5-6 then it is false knock. I would check the transmission dipstick tube and also see if your downpipe is close to your swaybar as you may have to flip it. This may be different on an impala but I do believe it is the same setup as far as a "rolling chassis" is concerned.
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I read that thread about you possibly getting that dhp tuner so if thats the case just decrease the timing in the cell that you are getting the flash kr in and see if it goes away...There are manny things that could cause false kr...the things stated above and even tranny noises
 
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