Yeah I didn’t mean ditch them like keep them off just tuning. I’ve been able to tune off stfts pretty easily I do agree the wideband isn’t that accurate as it’s like if I’m in a rich cell it doesn’t read rich only wot it will kick to 13 which is lean. So keep tuning off fuel trims then wot tie the wideband in and use that then? I mean if everything is done correctly with fuel trims wouldn’t it align with the wideband at the end of it all?
I always turn off all the extras, it over-complicates and offers very little in return for the effort and targets unwanted air fuel ratio anyways. Not needed if you are tuning the vehicle yourself with a wideband which can target anything you desire. Fuel trims are good for if you plan to stop tuning the vehicle and drive for a long time and go different places so the fuel trims can compensate for slight changes over time. It also helps if you aren't really good at tuning because the computer is tuning for you over time to help fix mistakes, I think that is why most people like it.
If you will always have a laptop available and hptuners to make slight corrections you won't need the auto-trims because you can correct yourself, you are the trim feature.
It simplifies the tuning process, remove the maf, remove the fuel trims, remove any complication to a basic simple process and just tune it quickly to some targets you desire. shrug
You can try both ways. Or pick one. I am not pushing my method only saying I've used it successfully hundreds of cars 25 years and that any aftermarket stand-alone ECU on the market currently uses a wideband target lambda feature which is what we are trying to replicate. In other words your ECU from the OEM Lacks a closed loop wideband so our only option to turn it into a successful stand-alone ECU style tuning effort is to run open loop wideband and finely tune it perfectly. If that makes sense. This way you can have a stand-alone aftermarket ECU performance without the chains and complications of the OEM methodology and ancient narrowbands which no aftermarket ecu uses anymore for a good reason.
Your wideband should be more accurate than a narrowband by a long ways. If it isn't there is some issue like exhaust leaking or mounting position. A wideband has a narrowband inside it. They are essentially the same thing except the wideband has one extra piece of advanced technology to make it superior.
Here are your targets I recommend for daily drivers, natural aspiration, then take to the dynometer and adjust the final enrichment from say 11.8 to 12.3 find the richest most power you can make.
Technically yes. I've even messed around with low power setups and made them stay in closed loop the whole time and plotted out a VE. Then when combined with the PE you should end up with your target A/F. But even doing most of the table in closed loop and extrapolating it out you should get real close to your target A/F as long as your fuel pressure does not drop. That's key. Need to have a pressure gauge on the vehicle, one that you can view from the driver's seat. Keep it on the vehicle for the duration of the tuning process. Too many people jump into tappin at the keyboard and never cover the basics. Gotta know what the FP is at all times.Originally Posted by Lxjoshxl
EFI specialist
Advanced diagnostics, tuning, emissions
HPtuners dealer and tech support
email=[email protected]
Here are some examples from stand-alone tuning we use Closed Loop Wideband to target these ideal a/f ratio for particular combinations
This one is a 2.5L powerglide running 35psi alternates between 93 and E85 so there are some Alcohol enrichments that take place on top of this display values, Haltech ECU
This was a 13:1 compression 427cid LS style engine in a heavy vehicle with 4l80e, Holley ECU closed loop wideband
None of these targeting is possible in closed loop with narrowband sensors. It will not allow you to refine the target like a true stand-alone ECU.
It also prevents you from enriching gradually. With the OEM ecu in closed narrowband it will produce 14.7's all the time and then suddenly smack with power enrichment rich air fuel ratio. This is not ideal or desirable, you want a gradual change in air fuel enrichment over time smooth, not a sudden full rich condition. Just ridiculous to leave it like that when we have full control. But some people think its 'the right way' just because the factory does it that way.
Finally here is my car example. Tuned around 2020 I put 40,000 miles since then open loop and as you can see still tuned just fine, never been closed loop never used a narrowband, I daily driver it and achieve superior fuel economy and drivability that the factory methodology.
https://www.youtube.com/watch?v=1y09lYL4Now
0:05 get on highway cruise note 16's
3:38 note 15.8 to 16.0:1 still cleaning plugs @ 65mph in traffic
5:18 kick out of lockup and small boost in 4th to move up in traffic
6:29 step down lightly into lockup for some boost in 4th
7:18 get off highway
8:23 downshift rip the tires loose at 50mph
9:12 slowing down for stoplight
9:20 Showing A/F Stopped at stoplight note 14.7 to 15.0 open loop steady
10:51 leave light, turbine whistle
11:30 cruising 15.6 to 16.0 housekeeping plugs
12:18 rip tires loose at 50mph 'spool character'
13:05 stopping for traffic light
13:10 show a/f for traffic light stop 15.5 walking into 14.7 to 15.0 open loop
13:52 2nd gear chirp coming leave light
It's not a standalone system. It doesn't have functional widebands. You can't tune a GM computer open loop and make it work like a Holley. Simple as that. To promote open loop tuning on 90% of the street vehicles being discussed here is hack tuning.
Just wow!.jpg
This is not an accurate VE table. Anyone who comes up with that should never be listened to about anything.
EFI specialist
Advanced diagnostics, tuning, emissions
HPtuners dealer and tech support
email=[email protected]
so edcmat you dont believe in failing the maf and tuning ve that way? i do notice in speed density my trans definitely gets hot acts different as the maf isnt controlling it. I Hear a lot of different information all over the forums. King- Like you said I notice the wideband at 14.7 untill im wot then it goes into Pe and changes besides while its warming up i do not see much change in the wideband readings. I just want to get what I Can get with what I have. I Spent 300 for email tune he adjusted the maf 3 times sent me on my way. Fuel pressure is good no dropping on the gauge i lost a whole two weeks tuning with a bad fpr where it was dipping down a lot. I think either way im going to tie in the wideband into the logger. Im just confused now on to use the wideband to tune ve maf etc or to use stfts like I have been. Here is my tune and last log where im at now Where i Started is on first page, I just wanted to know if im headed in the correct direction so im not wasting time and peoples time on here helping me. I Bought the pro link cable but then reading it isnt worth spending the $$$ for the pro feature set just to log WB When I can push it through EGR and zero out the EGR Tables... I undertstand the stfts copy paste mutiply half smooth whole etc but then again reading on the forums a lot of people say its a waste of time and to use a WB
VE SD 22.hpt
ve sd 23.hpl
He's saying tune in CL, extrapolate out, verify with wideband.
What I do is set PE enables to 85kPa, 85%.
Go to Trans Diag>Max Line Pressure DTC and set those 3 to disabled. That'll fix your SD problems. Not many people talk about doing that for some reason.
All VE tables from all ECU are tuned that way,
Here is Haltech's master tech response for example, Mitch
mine goes from 82 to 92 which falls perfectly within the range of acceptable VE change for 100 to 200KPA
absolute perfection
Actually I made a mistake and he said this, quoted his words
-Mitch SmithYou can see the VE doesn't drastically increase with boost pressure, in fact from 0 boost to 22psi there is only a ~9% increase in VE, most likely due to compressor efficiency, fuel cooling etc. VE drops away after peak torque at 5000rpm as expected due to the stock camshafts. If I were to run higher boost that caused me to move outside where the compressor and turbine are efficient, VE would start to reduce with this pressure. I've added the O2 Control output channel to the screenshot so you can see there is no effect from O2 Control adding or removing fuel through the run.
Heres another ECU example
https://www.hpacademy.com/forum/prac...running-boost/
The VE at 200KPA should be very close to what it was at 100KPA. It logically flow in my file and my target and actual a/f ratio line up so it does indeed work this way.For the sake of argument, if you ignore the effects of compressor and turbine efficiency etc, if your engine has a VE of 100% at 1bar boost, it will still have the same VE of 100% at 2bar boost. Just when you convert that volume into mass the 2 bar example will be twice as heavy because the pressure and therefore density is. The law is PV = nRT.
Back when I had my Supra 7mgte I put a mega squirt system in it my buddy who lived close was very good with it. Seemed like the standalone setups are easier? That was years ago lol. So are there benefits of tuning In closed loop versus the way I’ve been tuning so far?
Stand-alone is just the basic necessary ingredients for performance applications to run an engine/trans. OEM Ecu have to cater to a number of additional sensors and devices for example emissions related or economy related. Some stand-alone like Haltech can still control those features though but they are optional, whereas the OEM ecu may be more difficult to 'get rid of' some things or has weird behaviors to get around. The OEM GM ecu has a way of tying torque and airflow together in such a way that makes it more difficult to tune than any stand-alone, yes. And as the generations go up from 3 4 5 they just become more difficult and require more specific esoteric knowledge. However in some cars removing the OEM ecu also makes keeping some vehicle functions like gauges or other electronics more complicated so people are often willing to pay a premium to get their OEM ecu tuned rather than go to a stand-alone for modern vehicles. The point being if you do not have that kind of vehicle- if you just have a basic setup you wanted tuned and driving and it doesn't have all that modern can-bus and internal vehicle communications devices than a stand-alone is much easier and powerful tuning tool than the OEM ecu.
In gen3 applications the OEM ecu is sufficiently simple that it can be almost tuned exactly like a stand-alone provided you are experienced tuner and able to understand what the ECU is capable of and how to tune a transmission properly and willing to disregard the OEM tuning methodology. To me, the point of unlocking the OEM ecu is to tune it different from the factory using my own methods which work for my vehicles and work my way, not to copy and try to tune it the way the factory does it. The factory is not correct and they rarely offer anything we would like to copy for any performance application, anytime you changed a factory engine part is a testament to the idea of going away from factory and doing your own custom work. The biggest threat when learning on a gen3 is due to airflow model which can influence the transmission and to some extent a couple other potentially annoying features. In this way I recommend keeping the airflow model accurate and true and fine tuning the transmission directly via pressure and force motor tables with a mechanical pressure gauge rather than relying on the airflow model to do it for you and assuming it is correct, again the factory seems to fall short when it comes to its OEM tuning vs what we want for a performance vehicle and longevity at higher output. In other words if we are changing tables, numbers, car parts, all going away from factory, then why do people cling so harshly to the factory tuning methods and original tuning ideology when it will produce suboptimal results? And there is nothing stopping you except knowledge from tuning it properly like a stand-alone computer would be, pretty damn close anyways.
The benefit to closed loop is you let the computer make fuel changes for you over time so when years goes by and stuff wears out it kind of compensates, sort of, remember the oxygen sensors are averaging cylinders so if one cylinder starts to get bad like a clogged injector or misfire it throws the whole side off, meaning the closed loop is making wrong adjustments and the real problem is mechanical or electrical anyways, either with or without closed loop its still needs to be fixed, closed loop wont save you. Another good thing about closed loop is if you lost your laptop or don't have the time to tune the engine fully, completely. Tuners that you pay for tunes love closed loop and they love maf sensors because both make life easy for them, they don't need to tune the engine as closely and carefully, its much faster to let the ecu adjust itself and the maf is a simple table can be done quickly. VE on the other hand combined with cold starts and seasonal changes and temperature variations ambient can take months to tune properly- or even years to get it perfect. And there is no tuner who wants to tune a car for months or years to get it perfect for the price you pay. It isn't that they are lazy its literally just too expensive nobody will pay that kind of money for a perfect tune. So this is where you come in to tune yourself and learn to tune and this is what makes the difference between a guy on the internet who tunes for money and you yourself- you will have the time and effort to put into the tuning to make it run perfectly and so you won't need closed loop if done properly. Whereas the pay to tune guys all need closed loop and think of it as the only way to tune a vehicle properly since they barely do any tuning at all and go from car to car over time quickly.
You need to decide how you are going to run it when you get done, and use that method to tune. Pretty much all of the professional tuners on here are going to set up a GM ECM to run in closed loop for every day driving.
Yes If I tune a vehicle for somebody and then let them drive it, the vehicle absolutely must be in some form of closed loop to have sustainability for long term operation. I never disputed that. Because no tuner including myself getting paid reasonably will spend enough time on a vehicle to tune it fully enough in open loop to maintain for every situation for what we are getting paid.
Yet this does not qualify the statement for individuals who purchased HPtuners for their own vehicles: 'pretty much all professional tuners' because those professional tuners are not the ones tuning that vehicle, it is being tuned by an owner themself. The owner with the laptop who is paying themselves to tune their own vehicle in time, limitless time, months and years of tuning for $0 just time and effort. In which case they are above professional tuners, superior in every way, because they can tune the ECU to its full capabilities fine enough to extract superior economy and drivability of an open loop tune. And let there be no mistake: open loop wideband GM ECU is superior in every way to a closed loop narrowband version of the same ECU when tuned properly.
The way I have been understanding is to disable ltfts run open loop, tune it then re enable ltfts dfco re enable maf then tune the maf after ve etc and after fueling is done then move on to spark tables after this. So essentially what you guys are saying is tune In closed loop if I’m going to run the vehicle in closed loop? I mean essentially I’m tuning closed loop right just speed density then I’ll re enable the maf but it’s still going into closed loop. For example cold start doesn’t start logging data untill temps are reached then I log data and go off of that
Last edited by Lxjoshxl; 11-20-2023 at 06:49 PM.
The way I would do is different from novice tuning efforts, but for the sake of explanation to intelligent beginners
1. write spark table from experience with minimized rational values for safety during tuning process
2. disable all fuel trim and unplug narrowbands remove the maf sensor fail the maf, if needed turn off dfco, remove minimum injector limits, disable all the bells and whistles so its just a base bare bones ECU
3. tune the ecu with wideband properly to hit target air fuel values for all driving inside application
4. adjust for optimal spark now that fuel is spot on and tune for application
5. Use dynojet to empirically test injection end of spray and finalize some fuel and timing values
The application could be boat, turbo, 1/4 mile, 1-mile, whatever, its all different methods of tuning fuel and spark there is no one size fits all tune. Background understanding of engineering, thermodynamics, physics, chemistry, heat transfer, all come into play with how well you understand how to take the energy of fuel molecules and turn it into force and heat, where the heat goes, how the force affects and changes the crystalline lattice of drivetrain parts and dissipates that energy as vibrational, mechanical, rotational, electrical, whatever
I then disregard the maf throw it away, and never use closed loop you don't need it since you own the laptop and if you see something wrong in the wideband you can fix it yourself.
If you are handing the vehicle to a sheep with no laptop of course you would want the closed loop turned back on for them to drive oblivious and maybe even remove your wideband since they don't know how to use it.
5.3/4l80e/turbo playthrough
https://www.corvetteforum.com/forums...ge-budget.html
cancer research
https://www.mdpi.com/2306-5354/10/1/96
Yes you're correct. Tune CL. Whether you're doing MAF or SD doesn't matter. CL for both. For a cammed engine I turn up the temps on the enables. STFT to 120 and LTFT to 140. Keep STFT open loop enabled.
well this is where im at feel like i the tables a mess still looking at the graph low rpm when the converter locks i get a lot of knock proably normal it seems like some times when i wrote the new data it goes away then when i log and re write it sometimes it comes back like bouncing back and forth ive tried getting into it 3rd gear 2cd gear high rpm trying to hit as many cells as i can but not sure how much crazier to go before i re enable and tune the maf.
VE SD 27.hpt
ve sd 35.hpl
XD lulz....
"I don't care how it runs as long as it chop chops at idle"
Reply With Quote
