What is the Dataviewer Telling Me? Round 2

[daswi]

Sorry guys it's taken me so long to run tests a second time. I've made a few mods to my car and added the rpm range to my diagnostics. If you download my log, you will find the action range between 5:00 and 5:20 there is a slight retard issue a little later. Someone please give your thoughts. TIA.

U7135
9r17
2009 Dodge Challenger R/T automatic

Mods
Magnaflow Cat-Back 16513
MM 85mm TB
JMB CAI
BT Catch Can
DS Perf 91 CAI Tune

[duster360]

I'd remove 2 degrees of timing from 4k-5k and retest.

Be sure to disconnect the battery to clear the 1 degree of LT knock retard before testing.

Do you have a wideband O2 at all? A reading of actual A/F would be nice.

[daswi]

I'd remove 2 degrees of timing from 4k-5k and retest.

Be sure to disconnect the battery to clear the 1 degree of LT knock retard before testing.

Do you have a wideband O2 at all? A reading of actual A/F would be nice.

I do not have a wideband. In your opinion, what should removing 2 degrees of timing do for me?

[duster360]

I'd remove 2 degrees of timing from 4k-5k and retest.

Be sure to disconnect the battery to clear the 1 degree of LT knock retard before testing.

Do you have a wideband O2 at all? A reading of actual A/F would be nice.

I do not have a wideband. In your opinion, what should removing 2 degrees of timing do for me?

The idea is that you should make more hp with 2 less degrees of timing and 0 KR than with your current timing and 6 degrees of KR. Removing 2 degrees of timing should hopefully prevent the PCM from forcibly removing 6 degrees via Knock retard. Knock begets more Knock. So usually if you can keep Knock from starting you can keep it away entirely.

Your knock is starting around 4000rpm and gets progressively worse up to 5500rpm. After your shift it peaks again around 4500rpm. So removing the 2 degrees from 4k-5k should help quite a bit.


Also,,datalogging a more "comprehensive" list a PIDs will help you(and others) understand what your adjustment are doing.

KnK ST Retard
KNK LT Retard
KNK Total Retard
Actual Spark Cy1( you can do other Cyls but there's USUALLY little difference)
Spark adjust
RPM
MPH
THR POSN
AV MAP TO USE
1/1 LONG TERM ADAP
2/1 Long TEM ADAP
PRATIO
ECT
ACT
OPEN LOOP FA

[daswi]

I'd remove 2 degrees of timing from 4k-5k and retest.

Be sure to disconnect the battery to clear the 1 degree of LT knock retard before testing.

Do you have a wideband O2 at all? A reading of actual A/F would be nice.

I do not have a wideband. In your opinion, what should removing 2 degrees of timing do for me?

The idea is that you should make more hp with 2 less degrees of timing and 0 KR than with your current timing and 6 degrees of KR. Removing 2 degrees of timing should hopefully prevent the PCM from forcibly removing 6 degrees via Knock retard. Knock begets more Knock. So usually if you can keep Knock from starting you can keep it away entirely.

Your knock is starting around 4000rpm and gets progressively worse up to 5500rpm. After your shift it peaks again around 4500rpm. So removing the 2 degrees from 4k-5k should help quite a bit.


Also,,datalogging a more "comprehensive" list a PIDs will help you(and others) understand what your adjustment are doing.

KnK ST Retard
KNK LT Retard
KNK Total Retard
Actual Spark Cy1( you can do other Cyls but there's USUALLY little difference)
Spark adjust
RPM
MPH
THR POSN
AV MAP TO USE
1/1 LONG TERM ADAP
2/1 Long TEM ADAP
PRATIO
ECT
ACT
OPEN LOOP FA

Thanks Duster. I'll add the other PIDs and post another datalog.

[Illss1]

Not to threadjack but is it a MUST to disconnect battery if ur getting 1.0 - 1.5 deg of LT knk retard ? I just added fuel +2 % to the already +6 and it went away but i still got the ST knk 3.0

[Quick]

No. First of all you're only adjusting fuel and timing at Wide Open Throttle. That's a separate operating mode the PCM goes into when you floor it. It doesn't remember anything from the last time your floored it

[duster360]

No........ It doesn't remember anything from the last time your floored it

This is completely false in reference to any Long Term adaptive learning(Lt fuel trim or LT knock).

LONG TERM knock retard is just that. Its a semi- permanent change to the timing tables. If you have any LT knock it will remain until its cleared from memory or the PCM slowly retracts it. Just as LT KR rises in response to ST Kr, it will also lower is ST stays on 0 long enough(minutes, hours, Weeks,,who knows.) If LT KR is always pulling 4-5 degrees of timing, performance will be less than optimal, regardless if ST KR is 0.

Lt fuel trim is usually inactive at WOT because its driven from the feed back of the upstream O2 sensors, which are ignored in open loop. LT fuel trim can pop up at WOT level P-Ratios from timie to time.

Lt Knock retard, on the other hand, is always in affect(mapped by PR vs RPM) regardless whether the PCM is running in open or closed loop.

[duster360]

Not to threadjack but is it a MUST to disconnect battery if ur getting 1.0 - 1.5 deg of LT knk retard ? I just added fuel +2 % to the already +6 and it went away but i still got the ST knk 3.0

Even though your ST knock is reduced, the LT kr will remain until you clear it.

If your ST KR remains often enough at 3.0 degrees, the PCM will keep pulling timing and adding it to your LT KR until the ST is 0. Overall, you'll still be running less timing than the original WOT timing table allows.

[Illss1]

Ok so if i have this LT knock and im trying to get rid of it do i disconnect battery then make the adjustments on predator ? Like if im already getting the LT knock and wanna add or take away without the battery thing will it work or am i gonna have this 5-6 deg pulled no matter what at wot til battery is disconnected? Sorry im confused an didnt sleep well last night . Lol

[Quick]

No........ It doesn't remember anything from the last time your floored it

This is completely false in reference to any Long Term adaptive learning(Lt fuel trim or LT knock).

Really? where are you getting your information?

Long Term
The second fuel correction program is the long term adaptive memory. In order to maintain correct emission throughout all operating ranges of the engine, a cell structure based on engine rpm and load (MAP) is used. The number of cells varies upon the driving conditions. Two cells are used only during idle, based upon TPS and Park/Neutral switch inputs. There may be two other cells used for deceleration, based on TPS, engine rpm, and vehicle speed. The other twelve cells represent a manifold pressure and an rpm range. Six of the cells are high rpm and the other six are low rpm. Each of these cells has a specific MAP voltage range Typical Adaptive Memory Fuel Cells . As the engine enters one of these cells the PCM looks at the amount of short term correction being used. Because
the goal is to keep short term at 0 (O2 Sensor switching at 0.5 volt), long term will update in the same direction as short term correction was moving to bring the short term back to 0. Once short term is back at 0, this long term correction factor is stored in memory.

So the cells are indexed by RPM and MAP. The long term adaptive is updated from the short term adaptive each time you enter a cell. So all you have to do is switch cells for the long term to update (could just be back and forth between 2 adjacent cells). The short term adaptives are moving about 2 times a second? I'm guessing you might only need to run up and down through one gear to cross enough cell boundaries to move the long term fuel adaptives their maximum range of 25% of the base injector pulse width from the lowest part of the range to the highest part of the range. You think there's anything to that?

[Quick]

Lt fuel trim is usually inactive at WOT because its driven from the feed back of the upstream O2 sensors, which are ignored in open loop. LT fuel trim can pop up at WOT level P-Ratios from timie to time.

The values stored in long term adaptive memory are used for all operating conditions, including open loop and cold starting.

I could be completely wrong because I'm not a tuner and I could just be misreading and/or misinterpreting the service manual.

[mnunes]

I believe that simply loading a tune clears ALL of the adaptives, long and short term, so there shouldn't be any need to disconnect the battery.

[Quick]

I believe that simply loading a tune clears ALL of the adaptives, long and short term, so there shouldn't be any need to disconnect the battery.

Yes, there is that . but this also comes up when people change or install something like a CAI without touching the tune.

[duster360]

I believe that simply loading a tune clears ALL of the adaptives, long and short term,

Not that I've ever seen.

I've observed that if LT kr or LT Fuel has set a -/+% before a flash its still there right after a flash.

LT adaptives don't update until ECT is Over 176F. So if your statment were true, ANY and ALL LT adaptive would remain 0% until this ECT temp is reached. This is not the case.