Welcome Guest!!!

Thank you for visiting the GM Kappa Performance Forum. This forum is the only performance oriented forum for all GM Kappa Platform Enthusiasts.  We hope you will join and share your experiences.  Becoming a member is FREE! If you want to advertise on this forum, email KappaPerformance at yahoo.com.


Registration required to view the forum attachments. Below is a sample of the current top 25 topics.
Supporting Membership has many advantages.


More information on becoming a supporting member or vendor can be found on the sub forum; Site Help and Suggestions; thread - Supporting Members and Vendors.

Author Topic: Does the ECU learn down? Debate about it here.  (Read 32093 times)

0 Members and 1 Guest are viewing this topic.

Offline kennysabarese

  • "The Professor"
  • Premium Member
  • Gearhead
  • *
  • Posts: 3809
  • Karma: +0/-5
  • Location: NJ
  • Make or take?
Does the ECU learn down? Debate about it here.
« on: September 08, 2010, 02:18:27 PM »
Talk amongst yourselves  :)
2007 Sky Redline - Wester's Tuned - GMPP sensors - RMR Roll Bar - Kirkey Seats
Schroth Harnesses - SSR Wheels - Dunlop Direzza Z1 Star Specs - Complete Mod List
kennysabarese.com - Photos - Facebook - Twitter - RSS

Offline Gentleman Jack

  • Chief Financial Officer, Color Professional
  • Premium Member
  • Shop Foreman
  • *
  • Posts: 8985
  • Karma: +25/-82
  • Location: Unknown
  • I'm here. If I wasn't here, I'd be there.
Re: Does the ECU learn down? Debate about it here.
« Reply #1 on: September 08, 2010, 02:29:24 PM »
I'm feeling veclempt.
Make the right choices now

Offline kennysabarese

  • "The Professor"
  • Premium Member
  • Gearhead
  • *
  • Posts: 3809
  • Karma: +0/-5
  • Location: NJ
  • Make or take?
Re: Does the ECU learn down? Debate about it here.
« Reply #2 on: September 08, 2010, 02:35:25 PM »
Sky 888 said this which seems to contradict itself

Quote
kenny, when the car is on the dyno to get max power and tuning upgrades...........it gets flashed every time there's some adjustment made in between runs.   There's really no need to "learn" to get the max power IMO.

so when Kelu flashes a new tune on the car when he's on the track, I don't think, there's no need for "learning"

I personally flash my "tune" every month on my car.  Even though its the same tune.......the engine feels more alive

To me alive would mean slightly more power... So maybe it's the opposite of what I said, that the car starts more aggressive but then learns down to a safe place.
2007 Sky Redline - Wester's Tuned - GMPP sensors - RMR Roll Bar - Kirkey Seats
Schroth Harnesses - SSR Wheels - Dunlop Direzza Z1 Star Specs - Complete Mod List
kennysabarese.com - Photos - Facebook - Twitter - RSS

Offline DeepBlueGXP

  • KappaPerformance Site Owner
  • Administrator
  • Shop Foreman
  • *
  • Posts: 9215
  • Karma: +12/-6
  • Location: Southern Maryland
  • Displaced Buffalo Bills Fan
    • Kappa Performance Forum
Re: Does the ECU learn down? Debate about it here.
« Reply #3 on: September 08, 2010, 02:43:02 PM »
It's not that it's learned down, the car has basic fuel trims that as used/saved based on the quality of fuel and your driving habbits.    Pulling fuses 42/43 clears fuel trims or you can use a dashhawk to clear them.   

Prior to Westers Tune, modifications to the car, i.e. cat, waste gate were learned out as the ECM has a torque limit.  Westers Tune removed the torque limits and thus there isn't any learn down.

Offline NormSky

  • Premium Member
  • Master Tech
  • *
  • Posts: 724
  • Karma: +0/-0
  • Location: OH-IO!
Re: Does the ECU learn down? Debate about it here.
« Reply #4 on: September 08, 2010, 02:44:16 PM »
You'd have to datalog to see what is really going on. Otherwise the butt dyno can be quite deceptive.
07 Sky Hahn Boosted - 44 MPG  40 mpg with air conditioning on.

Offline kennysabarese

  • "The Professor"
  • Premium Member
  • Gearhead
  • *
  • Posts: 3809
  • Karma: +0/-5
  • Location: NJ
  • Make or take?
Re: Does the ECU learn down? Debate about it here.
« Reply #5 on: September 08, 2010, 03:01:07 PM »
Ok so this is a different "learning" that I may have been thinking of in my original question to Kelu.

Yes the stock ECU will lower the torque output of the engine when you apply bolt ons, but that is removed with Wester's tune and the GMPP tune. That was not what I was referring to, sorry if that was unclear.

Each time you start the engine for example, the car test the fuel quality by advancing the timing and causing the engine to knock a little then dialing it back down.

Also when I flash my car with an updated tune from Lyndon, sometimes I don't get full boost right away, but after driving a bit it will allow it to boost higher. So something changes. This is what I was referring to.
2007 Sky Redline - Wester's Tuned - GMPP sensors - RMR Roll Bar - Kirkey Seats
Schroth Harnesses - SSR Wheels - Dunlop Direzza Z1 Star Specs - Complete Mod List
kennysabarese.com - Photos - Facebook - Twitter - RSS

Offline DeepBlueGXP

  • KappaPerformance Site Owner
  • Administrator
  • Shop Foreman
  • *
  • Posts: 9215
  • Karma: +12/-6
  • Location: Southern Maryland
  • Displaced Buffalo Bills Fan
    • Kappa Performance Forum
Re: Does the ECU learn down? Debate about it here.
« Reply #6 on: September 08, 2010, 03:13:14 PM »
Everytime you re-flash the tune, the fuel trims are reset and it takes a few hard runs to get it back.    That's why I never reset fuel trims prior to a dyno.  I will how ever, reset fuel trims on the way to the track and I usually (20+ miles) get on it every chance I can on the way there.  That way my daily driving grind where we go no faster than 25mph on the way (heavy traffic makes you drive like grandma) is erased

Offline kennysabarese

  • "The Professor"
  • Premium Member
  • Gearhead
  • *
  • Posts: 3809
  • Karma: +0/-5
  • Location: NJ
  • Make or take?
Re: Does the ECU learn down? Debate about it here.
« Reply #7 on: September 08, 2010, 03:19:26 PM »
I thought that the only purpose of STFT and LTFT is when the amount of fuel given based on what the MAF tells the ECU is too high or too low. The O2 sensors catch this and fix it immediately.
2007 Sky Redline - Wester's Tuned - GMPP sensors - RMR Roll Bar - Kirkey Seats
Schroth Harnesses - SSR Wheels - Dunlop Direzza Z1 Star Specs - Complete Mod List
kennysabarese.com - Photos - Facebook - Twitter - RSS

Offline SKY888

  • Gearhead
  • ****
  • Posts: 2305
  • Karma: +3/-3
  • Location: near you
Re: Does the ECU learn down? Debate about it here.
« Reply #8 on: September 08, 2010, 09:05:57 PM »
Sky 888 said this which seems to contradict itself

To me alive would mean slightly more power... So maybe it's the opposite of what I said, that the car starts more aggressive but then learns down to a safe place.


not really sure....why the stuff I posted is contradictory?

All I said was simple..............on a dyno tuning session, in between runs, a tuner adjust the tune and FLASH it on the ecm.   The engine/ecm doesn't have to "learn" to improve the horsepower on that next run......

so I'm not sure why Kelu......right before a 1/4 mile drag race run............when he FLASH his "Nitrous tune".......needs his engine to "learn" first.  Or drive his car for a few miles or so.....

does he really need to have his engine LEARN after the flash?

maybe Kelu can do a trial and error test for us to see the truth behind this....





COMPOUND TURBOS (GT2860r & GT4294r) goal 800hp


CAR SPECS and PHOTOS:
https://www.facebook.com/SKY888CompoundTurbo

SPONSORS:
aeroforce.com, nitrofreeze.com, forgestar.com, splitsec.com, turbosmartonline.com, k1technologies.com, supertechperformance.com, specclutch.com, rceng.com, statusracing.com, tceperformanceproducts.com, burnsstainless.com, performanceautowerks.com, ddmworks.com, turbowerx.com, BTF

Offline SKY888

  • Gearhead
  • ****
  • Posts: 2305
  • Karma: +3/-3
  • Location: near you
Re: Does the ECU learn down? Debate about it here.
« Reply #9 on: September 08, 2010, 09:17:21 PM »
You'd have to datalog to see what is really going on. Otherwise the butt dyno can be quite deceptive.


Not just butt dyno, I also data logged last year and early this year.

Re-flashing every month, not just makes my engine feel more "alive"................data logs also shows that after every re-flash of the same tune............I have very little to zero KRs..........compared to a month-old tune that hasn't been reflashed.    The KRs are also very minimal to none......especially on a slow uphill climb........

Maybe its just a coincidence......or maybe its just my weird ecm.....

but it doesn't really mean, that these frequent re-flashing adds power though.....

it just feels more alive.......maybe because it doesn't have KRs that affect the timing of the car....

COMPOUND TURBOS (GT2860r & GT4294r) goal 800hp


CAR SPECS and PHOTOS:
https://www.facebook.com/SKY888CompoundTurbo

SPONSORS:
aeroforce.com, nitrofreeze.com, forgestar.com, splitsec.com, turbosmartonline.com, k1technologies.com, supertechperformance.com, specclutch.com, rceng.com, statusracing.com, tceperformanceproducts.com, burnsstainless.com, performanceautowerks.com, ddmworks.com, turbowerx.com, BTF

Offline NormSky

  • Premium Member
  • Master Tech
  • *
  • Posts: 724
  • Karma: +0/-0
  • Location: OH-IO!
Re: Does the ECU learn down? Debate about it here.
« Reply #10 on: September 08, 2010, 09:36:05 PM »
So Sky888's car feels alive after a flash and Kenny's is making less power after a flash because it's making less boost?
07 Sky Hahn Boosted - 44 MPG  40 mpg with air conditioning on.

Offline Uranium-238

  • V8 power...Acquired!
  • Premium Member
  • Gearhead
  • *
  • Posts: 3030
  • Karma: +1/-1
  • Location: Southern Maryland
Re: Does the ECU learn down? Debate about it here.
« Reply #11 on: September 08, 2010, 09:38:06 PM »
I think you guys need to come up with proper terms for what you're trying to describe. That way there's less confusion.

I'd say learn-down is the stock software's ability to adjust everything back to 260 ft/lbs of torque.

The engine "learning" a new tune would be better described as it adjusting to a new tune.
2005 Chevy Silverado Z71 Crew Cab, LM7 4L60E (What I traded my Kappa for. I regret nothing.)
2012 Chevy Camaro 2SS RS LS3 TR6060.
2021 Ram 2500 Cummins
2022 Jeep Wrangler Unlimited Rubicon. 3.6, manual trans.

Offline SKY888

  • Gearhead
  • ****
  • Posts: 2305
  • Karma: +3/-3
  • Location: near you
Re: Does the ECU learn down? Debate about it here.
« Reply #12 on: September 08, 2010, 09:41:29 PM »
I never experienced my car having LESS boost in between dyno tuning runs........never........
COMPOUND TURBOS (GT2860r & GT4294r) goal 800hp


CAR SPECS and PHOTOS:
https://www.facebook.com/SKY888CompoundTurbo

SPONSORS:
aeroforce.com, nitrofreeze.com, forgestar.com, splitsec.com, turbosmartonline.com, k1technologies.com, supertechperformance.com, specclutch.com, rceng.com, statusracing.com, tceperformanceproducts.com, burnsstainless.com, performanceautowerks.com, ddmworks.com, turbowerx.com, BTF

Offline tazz

  • Premium Member
  • Gearhead
  • *
  • Posts: 1624
  • Karma: +1/-2
  • Location: Somewhere
Re: Does the ECU learn down? Debate about it here.
« Reply #13 on: September 08, 2010, 09:44:05 PM »
A repost from HP Tuners
By Terminator2
Last paragraph talks about the learn down feature.


Here is my contribution to the LNF tuning thread. Contained in this thread are my thoughts on tuning and the LNF. I have posted smilar threads on other forums but I can expand on this information more on here than other forums without going right over people's heads with information so if anyone has a specific question to ask me please do so I can go more in depth.  I hope you guys like this. I wrote this many months ago and I can add to this if anyone want to ask me for more info on any specific subject. Because I know I may have missed a few things LOL.

The Gasoline Direct Injection (GDI) LNF uses a Bosch E69 GDI ECM. This ECM is a torque based engine controller containing approximately 2,500 tables that control all engine functions. There are approximately 600 tables that control fueling alone. A typical ECM contains only approx 250 tables total by contrast which is why a read entire takes about 10 times as long as most ECMs. A Gasoline Direct Injection (GDI) based fuel injection system is much harder to control and optimize than a typical Multiport EFI system which is why there are so many total tables In the ECM and so many that control fueling.

At the heart of this ECM is its torque based control system that uses driver input via pedal position to determine driver desired torque. Think of it as 100% pedal is equal to 100% driver desired torque. The driver desired torque value is fed into the Desired Airload table (DAL) which uses driver desired torque (pedal position) vs RPM to determine actual throttle postion. By raising or lower the DALs one can effect how the car reacts to pedal input from the driver. You can make 50% pedal 100% actual throttle opening or vise versa by raising or lowering those values. The DALs are regulated by the Maximum Airload Torque table (MALT) whch determines the percentage of actual airload allowed based on RPM. The Combination of the DAL and MALT helps determine actual throttle postion and does regulate the wastegate to some degree but does not allow for the desired boost level to be raised above 238 kPa, 34.5 psi absolute or 20 psi guage without modifying another table that we HP Tuners users do not yet have access to.

The GM stage tune rasies this desired boost ceiling to 255 kPa, 37 psi absolute or 22.5 psi gauge using the same Desired airloads one would normally to acheive 238 kPa. The Superchips Tune also raises the desired boost levels without changing the desired airloads. Which proves there are more boost control tables than DAL and MALT.

There is debate as to what is proper as far as what is Air to Fuel (A/F) mixture is appropriate for the LNF while in Power Enrichment Mode (PE) at Wide Open Throttle. PE ratios are expressed as Lambda where 1.00 Lambda = 14.69 A/F mixture when using gasoline. The Stock GM Tune and Stage one tune both use the same PE ratios of 0.95 to 0.87 lambda (14.0-12.8 A/F) I have seen anywhere from 11.4 to 14.0 PE A/F used depending on the tuner. I personally believe that the most effective A/F range for the LNF is 0.86-0.92 Lambda (12.6-13.2 A/F). PE lambda is influenced by Power Enrichment VS Time which is better known by most as the catalyst overtemp protection table or COT Lambda table. After a certain time at WOT once the ECM models a catalyst temperature of 1700* the ECM will richen the A/F mixture to as rich as 0.711 Lambda or 10.45 A/F at WOT. Most change those values to match their PE Lambda Table or if they are catless they set all values to 1.00 lambda to disable the extra enrichment.

Ignition and cam timing is another aspect of tuning this ECM as the LNF has variable valve timing. The VVT is controlled by cam phasers on each camshaft. The LNF has 4 sets of basic timing tables based on load, RPM, and Camshaft postion in relation to each cam's minimum and maximum states. Although there are more timing tables these are the main ones we are concerned with. Timing theories vary according to application but there is one universal truth. There is a point at which adding more ignition timing will actually cause torque and conversely HP loss which is normally but not necessarily due to knock retard. There is always a sweet spot where the mixture burns completely and just at the right time so that maximum cylinder pressure is reached right as the piston comes to Top Dead Center (TDC). That results in the the most work possible being performed on the piston (Large Force Acting on the piston for the most time possible) and hence the most torque output possible at that RPM. If the mixture burns too long from running too much ignition timing it will reach peak cylinder pressue well before TDC and the results will be spark knock and power loss, but if there is too little ignition timing run the mixture will not have sufficient time to burn completely and peak cylinder pressure will be reached after the piston passes TDC and the result will be less torque produced (Smaller Force acting on the piston for less time) The LNF is no different. It uses less WOT timing than any other engine I have ever seen partly do to the efficiency of the Direct Injection which produces much better fuel atomization and the comparatively lean mixtures GDI cars are known to run at WOT. Lean mixtures burn faster and hotter and require less timing because they burn quickly. Rich mixtures burn slower and at lower temperature and require more timing to burn completely.

There are over 20 camshaft tables but the only ones most would modify are the Intake Cam Main Warm table and the Exhaust Cam Main Warm Table. Many have wondered what the units in those tables are as they are undefined in HP Tuners. They are based on the camshaft's base circle. As I understand, the units influence how many degrees from center the camshaft is based on its base circle. So it is the camshaft itself that gives meaning to those units. That is why the values in the scanner are so much different than the values in the tables themselves and why it is possible to have a negative value in the table but a positive value in the scanner. Some have found small gains in top end HP by advancing the intake cam 2-3* in the upper RPM and upper load regions of that table. When you advance the intake or the exhaust cam you are asking it to open sooner. The theory behind a slight advance in intake cam timing is to open the intake valve a little sooner so the cylinder can take in more air on the intake stroke. Exhaust cam tuning theory is the opposite principle. You want to leave the exhaust valve shut as long as possible so that maximum cylinder pressure is reached before the exhaust valve opens. The problem is if you wait too long to open the exhaust valve peak cylinder pressure already have been reached before the exhaust valve opens. That means either knock will ensue or the piston will already be past TDC and the ability to generate peak torque will be lost. If the exhaust valve opens too soon (too much advance) peak cylinder pressure cannot be acheived before the exhaust valve opens and cylinder pressure loss and conversely power loss will ensue. Ignition timing and valve timing are inextricably intertwined as they have direct influence on one another. For example, advancing ignition timing coupled with retarding the exhaust valve timing will work togther to increase cylinder pressure but too much ignition advance or too much exhaust valve retard will be counter productive as it will likely result in knock retard.

The "Learn Down" feature. Because the LNF's ECM uses torque based controls it is much more advanced as far as limiting or adding to the torque that is desired from it. All modern ECMs that I have seen have Torque Management (TM) tables, and the LNF is no exception, but its entire engine management system is built around Driver Desired Torque vs Actual Torque Output. Driver desired torque is based on Pedal Position, RPM, Desired Airload, and Maximum Airload Torque. Those values determine Optimum Engine Torque which calculates engine torque output based on 1.00 Lambda. The Lambda Efficiency table changes calculated engine torque based on A/F Ratio expressed as Lambda. Leaner than 1.00 Lambda will produce less actual torque, and richer than 1.00 Lambda (up to a point) will produce more actual torque output. The "Learn Down" that most notice occurs when adding mods or driving in very cold weather they notice the boost pressure values have gone down. The ECMs torque based controls are to blame for this. If breathing efficiency is increased either from adding mods or from a denser air charge the ECM compensates for this by decreasing its Desired Boost pressure values. It does so because Actual Torque Output is modeled as greater than Desired Torque output. The GM Stage 1 tune raises the Desired Boost and Actual Torque output levels but does NOT completely remove the learn down but it does raise it. Other Tunes work the same way. They do not completely remove the learn down they merely raise it to a level that the car cannot acheive in the first place. Think of the learn down more like a target airload level or target torque output level. If you add mods or change the charge air density the ECM will sense that it is reaching its target torque output much more easily than before. That is not to say that adding mods without a tune will produce no gains at all. It is possible when adding mods like a catless DP and an Intake to make more power than stock even without being retuned. Although the gains are much larger if you retune the car I have seen evidence that even thousands of miles after adding mods a car will still dyno higher than stock. I have seen a stock tune LNF with an Intake and Catless DP make 254 whp and 272 wrtq thousands of miles after first adding the mods. That car stock on that same dyno would made 243 whp and 251 wrtq.

Offline kennysabarese

  • "The Professor"
  • Premium Member
  • Gearhead
  • *
  • Posts: 3809
  • Karma: +0/-5
  • Location: NJ
  • Make or take?
Re: Does the ECU learn down? Debate about it here.
« Reply #14 on: September 08, 2010, 10:05:16 PM »
Re-flashing every month, not just makes my engine feel more "alive"....

the reason i said contradictory 888 was because you are saying that the power output wouldn't change if you drive the car after a tune/flash/reset, but that you can feel a difference when you reset the ECM monthly

if the engine feels different, less alive as you say it over the course of the month, that means something is changing. not sure what to call it, but SOMETHING is changing.

so if it is true and something is actually changing, then it is probably affecting the output power of the engine. if it's enough that you feel it every month, i would have to say it's a measurable amount of power change.

EDITED THIS ONE A BUNCH OF TIMES. REREAD IT NOW
« Last Edit: September 08, 2010, 10:12:09 PM by Kenny »
2007 Sky Redline - Wester's Tuned - GMPP sensors - RMR Roll Bar - Kirkey Seats
Schroth Harnesses - SSR Wheels - Dunlop Direzza Z1 Star Specs - Complete Mod List
kennysabarese.com - Photos - Facebook - Twitter - RSS

Offline kennysabarese

  • "The Professor"
  • Premium Member
  • Gearhead
  • *
  • Posts: 3809
  • Karma: +0/-5
  • Location: NJ
  • Make or take?
Re: Does the ECU learn down? Debate about it here.
« Reply #15 on: September 08, 2010, 10:08:25 PM »
I think you guys need to come up with proper terms for what you're trying to describe. That way there's less confusion.

I'd say learn-down is the stock software's ability to adjust everything back to 260 ft/lbs of torque.

The engine "learning" a new tune would be better described as it adjusting to a new tune.
i am not talking about learn down here.

and it's not just adjusting to a new tune, because if you just reset the ECM something changes at that moment, and then changes over time as you drive, even though the parameters of the tune (tables in HPT) have not changed at all.
2007 Sky Redline - Wester's Tuned - GMPP sensors - RMR Roll Bar - Kirkey Seats
Schroth Harnesses - SSR Wheels - Dunlop Direzza Z1 Star Specs - Complete Mod List
kennysabarese.com - Photos - Facebook - Twitter - RSS

Offline SKY888

  • Gearhead
  • ****
  • Posts: 2305
  • Karma: +3/-3
  • Location: near you
Re: Does the ECU learn down? Debate about it here.
« Reply #16 on: September 08, 2010, 10:24:44 PM »
the reason i said contradictory 888 was because you are saying that the power output wouldn't change if you drive the car after a tune/flash/reset, but that you can feel a difference when you reset the ECM monthly

if the engine feels different, less alive as you say it over the course of the month, that means something is changing. not sure what to call it, but SOMETHING is changing.

so if it is true and something is actually changing, then it is probably affecting the output power of the engine. if it's enough that you feel it every month, i would have to say it's a measurable amount of power change.

EDITED THIS ONE A BUNCH OF TIMES. REREAD IT NOW

kenny, I personally can't say if the total PEAK POWER changed since I didn't dyno anything.

Like what I previously stated, there seems to be LESS KRs after I flash it.....and probably that's the reason why I feel the engine feels more alive.   But I'm not sure if the PEAK power is affected though.  Those KRs are only on low RPMs anyway.....and nothing on high RPMS....

anyways, I REALLY do not think that the ECM will need to "LEARN" after a RE-FLASH....to get its maximum power.   And an example is..........re-flashing in between dyno tuning runs.....
COMPOUND TURBOS (GT2860r & GT4294r) goal 800hp


CAR SPECS and PHOTOS:
https://www.facebook.com/SKY888CompoundTurbo

SPONSORS:
aeroforce.com, nitrofreeze.com, forgestar.com, splitsec.com, turbosmartonline.com, k1technologies.com, supertechperformance.com, specclutch.com, rceng.com, statusracing.com, tceperformanceproducts.com, burnsstainless.com, performanceautowerks.com, ddmworks.com, turbowerx.com, BTF

Offline kennysabarese

  • "The Professor"
  • Premium Member
  • Gearhead
  • *
  • Posts: 3809
  • Karma: +0/-5
  • Location: NJ
  • Make or take?
Re: Does the ECU learn down? Debate about it here.
« Reply #17 on: September 08, 2010, 10:27:54 PM »
it's just my theory that the power is changing. it may be less than 1% but i am just guessing that there is a change.

that's really strange that you develop more KR over the course of a month driving. how many degrees of KR?
2007 Sky Redline - Wester's Tuned - GMPP sensors - RMR Roll Bar - Kirkey Seats
Schroth Harnesses - SSR Wheels - Dunlop Direzza Z1 Star Specs - Complete Mod List
kennysabarese.com - Photos - Facebook - Twitter - RSS

Offline Uranium-238

  • V8 power...Acquired!
  • Premium Member
  • Gearhead
  • *
  • Posts: 3030
  • Karma: +1/-1
  • Location: Southern Maryland
Re: Does the ECU learn down? Debate about it here.
« Reply #18 on: September 08, 2010, 10:29:21 PM »
And people wonder why I want V8 power instead of this crazy LNF motor...

Alright, my head hurts. I think it's official: I hate this motor. Well, maybe just the software side.
2005 Chevy Silverado Z71 Crew Cab, LM7 4L60E (What I traded my Kappa for. I regret nothing.)
2012 Chevy Camaro 2SS RS LS3 TR6060.
2021 Ram 2500 Cummins
2022 Jeep Wrangler Unlimited Rubicon. 3.6, manual trans.

Offline SKY888

  • Gearhead
  • ****
  • Posts: 2305
  • Karma: +3/-3
  • Location: near you
Re: Does the ECU learn down? Debate about it here.
« Reply #19 on: September 08, 2010, 10:31:06 PM »
those KRs are very obvious on uphill climbs......when I'm going to work and parking my car on the 3rd level garage.

On the way up the garage.........usually it will be around 4-5 degrees..........

but after a re-flash, 1-2 degrees......and sometimes zero....
COMPOUND TURBOS (GT2860r & GT4294r) goal 800hp


CAR SPECS and PHOTOS:
https://www.facebook.com/SKY888CompoundTurbo

SPONSORS:
aeroforce.com, nitrofreeze.com, forgestar.com, splitsec.com, turbosmartonline.com, k1technologies.com, supertechperformance.com, specclutch.com, rceng.com, statusracing.com, tceperformanceproducts.com, burnsstainless.com, performanceautowerks.com, ddmworks.com, turbowerx.com, BTF

Offline kennysabarese

  • "The Professor"
  • Premium Member
  • Gearhead
  • *
  • Posts: 3809
  • Karma: +0/-5
  • Location: NJ
  • Make or take?
Re: Does the ECU learn down? Debate about it here.
« Reply #20 on: September 08, 2010, 10:37:17 PM »
those KRs are very obvious on uphill climbs......when I'm going to work and parking my car on the 3rd level garage.

On the way up the garage.........usually it will be around 4-5 degrees..........

but after a re-flash, 1-2 degrees......and sometimes zero....

very strange. the only thought I have there is that the ECU is trying to make the most power so it is advancing the timing slightly over the course of the month.
2007 Sky Redline - Wester's Tuned - GMPP sensors - RMR Roll Bar - Kirkey Seats
Schroth Harnesses - SSR Wheels - Dunlop Direzza Z1 Star Specs - Complete Mod List
kennysabarese.com - Photos - Facebook - Twitter - RSS

Offline tazz

  • Premium Member
  • Gearhead
  • *
  • Posts: 1624
  • Karma: +1/-2
  • Location: Somewhere
Re: Does the ECU learn down? Debate about it here.
« Reply #21 on: September 08, 2010, 10:42:35 PM »
Ive been messing around with my fuel trims and reflashing them every few days to dial them in and am almost there.  I can tell you the car does change and learn from the time it's flashed to the next few days of driving.  Our ECM is so complicated I highly doubt any of us except a few know whats it's actually doing considering our ECM has something like 2500 tables that control the way the car operates.  Take for example my fuel trims and I'm catless with a Wester's GMPP tune and GMPP CAI.  When I reflash both my trims sit at 0 for at least 4min at idle since it is in Open loop.  Once it's in closed loop the STFT's really go off the charts to 26.7% at idle which is the max positive adjustment for the STFT on my car at idle.  The AFR at idle is around 15.7 but will adjust down within another 2 min to around 14.7 and the STFT at 4% then the LTFT's kick in to adjust and now my LTFT's vary from +-1.6%.  Now I drive the car and it responds good but not perfect since it needs a base to go off of and over the next few days or key cycles the car actually drives better as it learns my driving habits and the Auto tranny has time to learn the way I drive.  In this time my LTFT's settle in and really don't vary much right now staying at 0% unless I drive my car really differently that I had been like getting on it all the time or driving sensably will change the LTFT's but not by much now only +-.8%.  While the STFT's on average have also settled down they can still swing +-10% BUT if I do a log and look at the averages it's +-2 in a 40min log with mixed driving in almost every cell except the 190+ load cells since I log up to the 270% load but usually only hit 240-250% load.  In those cells from 190+ the difference is greater at almost 5% average on the STFT's so I just need to raise the MAF correction factor in the 190% load cells to get them closer in line even past what HPT can adjust since the ECM uses the 190% load cells and RPM to determin what the STFT's are going to be past the 190%.  With the FT's adjusted that close the car responds much better and faster with less if any loggable KR going on and a very stable AFR that does not vary much with the command AFR.  Until the FT's settle in on my car the the AFR can and does vary almost +-.5AFR not sure if being catless affects this but if everything is in equilibrium my car runs like a camp.  Did some runs via the DH on 0-60 times and every time after 1 day they get better being on the same road with same temp and same weather conditions. At this time with temp in the low 80's I can replicate a consistant 0-60 times in the 4.42 sec range and with the worst being 4.5sec.  Before they settle in and everything gets a chance to learn the best time I can achieve is around a 4.7sec 0-60 time or a bit less.
« Last Edit: September 08, 2010, 10:50:28 PM by tazz »

Offline kennysabarese

  • "The Professor"
  • Premium Member
  • Gearhead
  • *
  • Posts: 3809
  • Karma: +0/-5
  • Location: NJ
  • Make or take?
Re: Does the ECU learn down? Debate about it here.
« Reply #22 on: September 08, 2010, 10:50:51 PM »
And people wonder why I want V8 power instead of this crazy LNF motor...

Alright, my head hurts. I think it's official: I hate this motor. Well, maybe just the software side.

My guess is a similar system is being used on NA engines as well. Especially on high end European cars. So maybe a BMW V8 would be just as complex.

It has it's advantages because our engine almost always makes the power output that it is it rated for by giving more boost. So in that way it's cool. NA you don't have that ability.

The problem is people are trying to change part of the tuning without having access to all of it, so no one will ever have the complete solution.

So yes this makes the LS engines attractive because HPT is far more developed there, so you have more ability to change things and people have been playing with them a lot longer than the LNF.

Easiest thing to do would be to get an aftermarket engine controller which is completely unlocked. They can be had for about the same price as HPT + Lyndon's tune.  They can control water/meth nitrous boost and more instead of buying individual controllers. Kelu has done a lot of research on this, says it should work on our engine.

GM racing using these on their Ecotec drag racing cars. Not sure if they have actually done it on the LNF though.

Who wants to take the dive! Lyndon would probably tune it for you. If someone will buy my sensors, tune, and HPT maybe I'll go for it. :)
 
2007 Sky Redline - Wester's Tuned - GMPP sensors - RMR Roll Bar - Kirkey Seats
Schroth Harnesses - SSR Wheels - Dunlop Direzza Z1 Star Specs - Complete Mod List
kennysabarese.com - Photos - Facebook - Twitter - RSS

Offline Uranium-238

  • V8 power...Acquired!
  • Premium Member
  • Gearhead
  • *
  • Posts: 3030
  • Karma: +1/-1
  • Location: Southern Maryland
Re: Does the ECU learn down? Debate about it here.
« Reply #23 on: September 08, 2010, 10:59:33 PM »
No no no, ditch the computer, ditch the fuel injection system, ditch anything with the word emissions, run a simple electronic ignition setup and off to the races...all sans computer, use nothing but mechanical components or simple electronics. Capiche?

That's what I'm looking for in an engine: Utter simplicity. Not computers.
2005 Chevy Silverado Z71 Crew Cab, LM7 4L60E (What I traded my Kappa for. I regret nothing.)
2012 Chevy Camaro 2SS RS LS3 TR6060.
2021 Ram 2500 Cummins
2022 Jeep Wrangler Unlimited Rubicon. 3.6, manual trans.

Offline SKY888

  • Gearhead
  • ****
  • Posts: 2305
  • Karma: +3/-3
  • Location: near you
Re: Does the ECU learn down? Debate about it here.
« Reply #24 on: September 08, 2010, 11:01:37 PM »
MY questions is............DOES KELU NEED HIS ENGINE TO "LEARN" AFTER A "RE-FLASH" BEFORE HE USES HIS NITROUS ON A 1/4 MILE RACE?


Most members say, that he needs to have his ecm "learn" first and do some runs................before he race?

why?








COMPOUND TURBOS (GT2860r & GT4294r) goal 800hp


CAR SPECS and PHOTOS:
https://www.facebook.com/SKY888CompoundTurbo

SPONSORS:
aeroforce.com, nitrofreeze.com, forgestar.com, splitsec.com, turbosmartonline.com, k1technologies.com, supertechperformance.com, specclutch.com, rceng.com, statusracing.com, tceperformanceproducts.com, burnsstainless.com, performanceautowerks.com, ddmworks.com, turbowerx.com, BTF

 

Powered by EzPortal