Ideal Idle AFR and Spark

[kingtal0n]

Oh here we go with the IAT



Relocate IAT to intercooler plumbing in front of the intake manifold
Use a plastic insulation washer
Use high quality GM IAT sensor
Heat shield to direct radiator fans
IMG-8468.jpg


You can also
desensitize the iat sensor in the ECU file for slight warming situations
Install a 500 to 1000ohm variable resistor to adjust the IAT as needed


The installed variable resistor is the most handy and powerful tool of all.
Even without IAT heat soaking you would still want one in a performance application- because there are IAT timing and fuel tables to compensate at WOT.
So the IAT variable resistor functions as a real time tuning tool. More timing? Less timing? More fuel? less fuel? Turn the dial. I don't know why people don't want control over their ECU in real time but nobody gets it.

[SiriusC1024]

Not this IAT heatsoak shit again.

IAT is reading accurately enough. When you're parked and idling hot air from the engine bay is being drawn into the intake. When driving hot air from the pavement is being drawn into your intake. Why are you trying to fool it?

The IAT isn't why you can't tune your car.

[kingtal0n]

Forget about heat soak.

Think about control. What control do you have over the engine.
With HPtuners real-time is difficult to achieve. And even then map have limited access like IAT.

So what do we do. Complain? Or add real-time controls to the ECU like IAT

Knob adjustment of IAT for leaning at altitude. Using 77 degrees setting for tuning.

https://forum.hptuners.com/showthrea...l=1#post682969


It is common sense from programming and tuning control perspective. Nobody told that guy to do this and yet he figured it out as common sense on his own.
The Aircraft gets it- why wouldn't you want a handy dial to adjust the air fuel and timing on the fly?

Who doesn't want that? Its just crazy. Good enough for aircraft but we reject it for our cars? Good luck if you never think outside a box, no progress.

[SiriusC1024]

Post #99 indicates he's planning to run closed loop. The open loop part is for tuning with wideband.

Imo tune with the narrowbands wherever possible using LTFT and STFT. Won't have to worry about such nonsense as IAT, atitude, phase of the moon, or any of that nonsense associated with OL.

Get the main airflow models correct. VE still needs work. I assume MAF does, too. Don't worry about getting idle exact until that's done.

[kingtal0n]

Post #99 indicates he's planning to run closed loop. The open loop part is for tuning with wideband.

Imo tune with the narrowbands wherever possible using LTFT and STFT. Won't have to worry about such nonsense as IAT, atitude, phase of the moon, or any of that nonsense associated with OL.

Get the main airflow models correct. VE still needs work. I assume MAF does, too. Don't worry about getting idle exact until that's done.

Think about the ECU at WOT which is 100% open loop

We have no control over IAT enrichment In closed or open loop for idle and cruise


ONLY WOT has comp tables for IAT accessible.


Therefore the IAT Dial is MAINLY FOR WOT. Spot fuel and timing adjustment for WOT.
Keep in mind WOT is definable. It can be 50% tps or 85% tps. Control.

Since we have FULL control over the IAT enrichment and timing for WOT this is the intended purpose

Control is everything.

[SiriusC1024]

LTFT's are referenced when going into PE. They are the offset to the airflow tables, so correct fueling in OL there is automatic.

[kingtal0n]

LTFT's are referenced when going into PE. They are the offset to the airflow tables, so correct fueling in OL there is automatic.

How can this be possible if there is no fuel trim for regions of the map where PE operates?
LTFT Must be based on closed loop correction. NO correction ever took place in PE so??

Even if this is true it only adds evidence for what I am saying. LTFT is going to move up and down over time due to ambient conditions. There is no such thing as a perfectly tuned map. The Fuel Trims are all over the place as variables change, +4 today, -1 tomorrow. This goes for all Closed loop ECU including wideband auto tuning ECU. Having a dial with which to increase or decrease fuel as needed or timing (or both) is ideal in either circumstance because the OWNER/OPERATOR can determine what is needed at that exact instant. The ECU cannot, it is 'blind' to real world conditions.

[SiriusC1024]

I mean this has taken almost 3 months to do what should have been as many days, and it's still not done. You guys are making this way harder than it needs to be. Keep wringing your hands over minutia and this tune might be ready by December.

[kingtal0n]

Here is what I found. It mirrors my own sentiment and I agree with Frost and several others about disabling the LTFT on this one.

https://forum.hptuners.com/showthrea...LTFT-s-and-WOT

Well while we are talking about dislikes... I dislike trim tuning! Use your wideband!

If you just disable them then you dont have to worry about them.,,,pretty simple procedure.

also a quick question....then I have your answer

what it means is that you need to retune your VE/MAF so that the trims are slightly negative so that it doesnt carry over into WOT/PE mode

our cars always add fuel if trims are positive, but never take away fuel if trims are negative.

Positive trims carry over from LTFT but not negative. So, sometimes. Interesting but I am not surprised with all the shenanigans of the OEM ecu.

If you think tuning via trims is comparable to tuning with a wideband, you haven't spent much time doing it both ways. That part isn't an opinion. I can map 3 VE tables before you can do really do the cruise portion of just one using trims; especially down low on anything with much cam and LTs. Trims make rocky-ass VE tables if you aren't constantly refining by hand too.

The more I think it about it, I'm not sure how using LTFTs on modded cars is just opinion either. I can make a list of reasons NOT to have them, but I can't really think of a reason TO have them if the car is properly tuned. What is the reason that you would want to keep them?

Frost my hero I've been trying to tell them this for years and nobody will listen they keep trying to use closed loop narrowbands to tune their engines... smh

after reading this thread I think just turning of the LTFT's will solve the problems I see with my PE at WOT.

Solved

[SiriusC1024]

All you did was resolve your own doubts about what I was saying with LTFT's carrying over to PE lol.

You have a way of explaining things that sound plausible to the uninitiated. Another thing you do is try to engage people on long drawn-out debates on issues that have little consequence. It's called mental masturbation.

I mean a variable resistor hack to make your car run right? That's a shit tune bottom line. Running OL is idiotic. Disabling LTFT's is idiotic. These procedures are only applicable in fringe cases. I see no evidence that this build qualifies.

I can entirely tune this car with the narrowbands in a day. The only limit to the pace would be how quickly logs are returned.

Since OP is struggling I'd suggest giving the method a try.

[kingtal0n]

All you did was resolve your own doubts about what I was saying with LTFT's carrying over to PE lol.

You have a way of explaining things that sound plausible to the uninitiated. Another thing you do is try to engage people on long drawn-out debates on issues that have little consequence. It's called mental masturbation.

I mean a variable resistor hack to make your car run right? That's a shit tune bottom line. Running OL is idiotic. Disabling LTFT's is idiotic. These procedures are only applicable in fringe cases. I see no evidence that this build qualifies.

I can entirely tune this car with the narrowbands in a day. The only limit to the pace would be how quickly logs are returned.

Since OP is struggling I'd suggest giving the method a try.

Narrowband air fuel ratio is garbage, useless. Who would do that? Only fools. There is nothing good about 14.7:1.

I've never used narrowband closed loop since 1998 when widebands became available for cheap. There is no point.

Modern ECU use closed loop wideband. HPtuners does not offer that feature so we use open loop. Its common sense.

Anytime you can add external adjustment to give or take 1% fuel or 1* of timing on a dial from inside the vehicle is a win. I win.

If you forget its there thats also fine. 99% of the time I don't use it. But when I want to , I have it. Control.

Control or not to control, that is the question.

[kingtal0n]

Heres my car driving highway, city, stopped at traffic lights, open loop. No IAT Variable resistor.

Fully tuned open loop means the a/f ratio is desirable and superior to closed loop.
If the vehicle is tuned properly, it doesn't need closed loop. Closed loop is only for corrections, when the FUEL MAP NEEDS CORRECTING.

Which never happens when I tuned the engine, you can't correct an ideal tune, its already ideal.


https://youtu.be/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 dowmshift 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

[Hondaeater]

I probably was. I have been swamped at work this time of year.

[Hondaeater]

Hondaeater I think you were confusing me with HQforme.

Sorry for the late response, been busy with other stuff and havent had much time to work on my car. So I figured my VE was riddled with bad data due to high IAT temps giving lean readings and erratic throttle input. What I did was grab the VE from before I did the swap and tried it out. Since I mistakenly thought higher VE numbers means more fuel I figured a bigger engine with a better intake would require more fuel. But after what youve taught me, I now know thats not the case. After swapping back to my old VE tune that I knew was good before I did the swap, it was much much better. It was overall rich ranging from 3-10% in regular zones and 15%+ in the high vacuum deceleration areas when the throttle is closed. Figured this was a great starting point so I pressed on.

I did a RAF log and copied over the numbers, then letting it idle for another 10-15 minutes after uploading that tune. Then the following morning right around the same time and ambient temp as the day before, I did another RAF log. It was almost completely perfect, only off by .5-1 g/s in most cells but the colder temps were around 1.5 g/s off. So I uploaded the new RAF numbers and let it idle for 15 minutes like yesterday. I did this 2-3 days in a row until the RAF on the cold start through operating temp was within +/- .3 g/s. Now my RAF is dialed in which is good.

It has been ungodly hot the past few weeks, especially the past few days, so ive only managed to get 1 good very long drive worth of VE error logging. Its now almost there, normal driving cells are within 3-5% with the exception of high vacuum decel areas which show about 15% rich still. Ive been battling IAT temps like crazy. If I stop at a light for more than a minute my IAT temps are well over 120. Even high way driving at 80 mph doesnt help much and usually only lowers temps down to 97 while driving. Ocassionaly I can get it down to low 90s to high 80s if I coast a lot but it goes back within a few minutes of driving. Ill upload the logs and respective tunes.

For some reason CL causes a really bad lean condition on tip in that does not happen on OL (unless IAT temps get ridiculous but even then it maxes out at 16.5-17:1). Not sure if thats a transient issue but just weird that it happens on in CL.

Finally, id like to get some input on how to keep my IAT temps in check. Seems like driving between 12-4 pm is near impossible if im not constantly driving. After 4 is not much better until the sun is mostly down around 6-7 pm. What I plan on doing is using some heat reflective tape on the intake lid (cries cause I got a clear lid) to try and get rid of some heat transfer from the engine bay. If that doesnt have enough effect, ill reluctantly pull off the headers and wrap them in heat wrap. What else would yall suggest?

LQ9 Tune 4.9 = Updated tune file with pre-swap VE
LQ9 Tune 4.10 = VE changes from 4.9 log

Unfortunately, LQ9 Tune 4.10 (4.9 log VE change).hpt is OL if all you did was put that into CL then cool. If you made changes to the OL tune and ran in CL, please post CL tune.
In CL it only idled for 15 seconds and was only at 128-132 degrees and enters CL when you started driving. LTFT does not start working until 149deg. Any data gathered while not at op temp is useless for calibrating the fuel tables.

What is the ambient outside air temperature during the logs? That is what the IAT ideally would be.
As far as the "CL causes a really bad lean condition on tip in" if you look you still have the DFCO disabled. Expect the decel to be rich and since in CL the ECM was aggressively pulling fuel in decel, when it is time to GO and you tip in there is a lean spot until the air and fuel delivery stabilize. Transient is part of the fix. but you have more work to be done before that. In OL that decel reduction of fueling does not happen and so you do not experience the lean tip in it is actually close to target or rich.. It took over 11 minutes to get a response from WB and you are in OL? Nothing before that is useful data? Bummer.

In the CL10 log, did you try the method to gather data I mentioned? It is a little confusing what you are trying to do here.
LQ9 4.10 CL Test Log.hpl Take a look at 16:16 minutes in the time stamp. You are coasting and at speed, 1800rpm, closed TB. See the Throttle cracker airflow amount is enough to hold your RPM even though you are closed TB?? Might want to lower that if you do not want the Cruise control effect at that speed vs RPM in the Cracker table.
Then you tip in 16:18. With me so far?
16:18 to 16:19 timestamp, you have opened the TB 27percent. Cool. FOR 2 SECONDS, then you start lifting pedal, closing throttle. At that speed you are not going to go much faster at 27% TPS anyway but the throttle starts to close here. That gives us 2 seconds of data before TB changes and that data is useless because it was not stable from the tip in. Starting at 1200rpm, for a what I call a "ramp run" ok, starting from 1200-1500rpm at one of those TPS described earlier, KEEP pedal at same tps until it reaches 4000rpm or it quits accelerating. At this speed, 15-27percent TPS is not going to yield much more RPM than you are starting at?? If you would start out the whole process in 1st gear, you would see the results quick and easy.

1st gear, start at 1200rpm and tip in to 15 tps. Holding that TPS until you reach 4000rpm, but it won't, it will stop accelerating before the 4000 rpm ceiling and that is fine! When you reach 4000rpm OR it stops accelerating then that portion of this data has been gathered, NOW either slow down in 1st gear back to 1200rpm and tip in to 30-35 TPS and HOLD till guess what, yep it either hits 4000rpm or it stops accelerating. EITHER that option or because you have used 1st gear at 15 tps and it stopped accelerating you CAN shift to 2nd gear and don't forget, slowing down in 2nd to 1200RPM do the same thing in 2nd, 1200rpm tip in to 15TPS and HOLD until... yep it reaches 4000rpm or it stops accelerating. The road really determines which of those scenarios works best for you. I like to shift into next gear AND SLOW DOWN TO GET RPM TO 1200 before starting the tip in for that gear.. in this case 15 TPS since we are starting out, after going thru the gears at 15tps then move to 30-35tps and starting at 1200-1500rpm repeat the same tip in and HOLD until 4000rpm or it quits accelerating. In an automatic it keeps fluid cooler upshifting rather than holding it for multiple "ramp runs" in same gear.
Back to the 4.10CL log, it looks like the 4th gear at that speed, 2000rpm, 70kPa, and 15TPS is dialed in. It shows +/- 2percent. Unfortunately you need to populate the VE table in more than that 70kPa 2000rpm range.

Look at the log at 3:58 timestamp. This was during some gear changes ok, look at pic below, and then after opening 32 TPS, 2200rpm holding for oh dang ONLY 2400RPM then started to close throttle. Bummer. Look at this pic, see those other ramps during the gear shift, 1 actually starts at the 1600rpm looking good, oh wait then the tps continues to increase to about 2500 when you shift gears, oh well lets try the next gear ramp up again same pic, oh it STARTS at 2200rpm not 1200-1500 but lets see what this gives us... at 2500rpm solid 33TPS but it only lasted 2 seconds, UHGG, and the next 1 is what I was talking about it started good even if higher 2000rpm start but by the time it was 32tps, and steady airflow it only lasted 4 seconds and throttle starts to close.

This data is JUNK. The time between shifts is about 3-5 seconds and of that there is little steady airflow with TPS being HELD in 1 position long enough.

....Always safety 1st, these are techniques that have worked for me and are suggestions to gather data, proceed at your own risk....

Try to get a log in 1st gear.
Start at 1200 rpm
open throttle quickly to 15 TPS (milking the throttle slowly to get to the target of 15tps or ANY of the TPS positions will waste precious data in the lower rpm vs kPa part of the table, open smartly and reach target tps quickly, practice before logging to get a feel for it and not trying to figure it out while logging)
HOLD until 4000rpm or it stops accelerating.

Slow down to 1200rpm again 1st gear.
open throttle QUICKLY to 30-35 TPS (if you overshoot tps, that is ok just keep it at that overshot TPS for the duration of ramp run, do not try to lift throttle to get back to the target of 30-35%)
HOLD until 4000rpm or it stops accelerating.

Slow down to 1200 rpm again 1st gear.
open throttle quickly to 45-55 TPS (but do not open so fast as to spin the tires lol)
HOLD until 4000rpm or it stops accelerating.

If you have time do that same thing in 2nd gear.
Start at 1200 rpm
tip in 15 TPS
HOLD until 4000rpm or it stops accelerating.

Slow down to 1200rpm again 2nd gear.
Open quickly 30-35 TPS
HOLD until 4000rpm or it stops accelerating.
Do you see the pattern here? That is repeatable and will get that VE table filled in quick and accurate on the road.
It will have some overlap from tps targets and gear changes. That is good so the AVERAGE shows up in the graph. If there is a kPa vs RPM area that is left unpopulated using those TPS targets, you can focus on that after you have gone thru at least the 3rd gear (manual, 2nd gear auto) using 15, 30-35 and 45-55 TPS openings.

very little steady data collected.JPG

[WS6_LOU]

Sorry for the late reply, been swamped at work and the weather hasnt been to kind either. But yes I did your method while just driving normally as well but that particular day had heavy traffic and unfortunately I dont think people would appreciate me running them off the road or rear ending them lol I did log long enough to eventually get enough data in the normal driving areas to average out the errors. As of now id say 90% of my cells are +/- 2% but the entire table is under 5% (minus high vacuum cells on decel but that should take care of itself when I reenable DFCO I think). Drivability is really good, AFR stays around 14.7 +/- .5 and WOT is around 12.5-12.8. I have moved on to changing the effective area and started to notice that a lot of my issues were coming from this. I had to tweak them quite a bit and im still not done but its much much better. The only remaining issue is my AFRs shifting lean after coming up to operating temp and letting it sit for 15 minutes-20 minutes while I ran errands.

What I have planned is to convert the remainder of my fuel system so that it feeds to the rail and then returns to the tank from the rail. That way I can use -8 fuel line with a good fuel pressure regulator and 40 micron filter. Figured the lines were old anyways and I should really be using bigger fuel lines anyways like you had pointed out. Hopefully that will reduce fuel temps. Work has just been killer and I havent had much time to do anything to the car. Hopefully I can get that done in the next month or so.

As for the AFRs shifting lean I will try to adjust the OLFA but seems to me my issue isnt just start up but also while driving so I may have to also adjust the cylinder charge temp bias and hot soak enrichment tables. I have no real idea on how to tune that so if one of you can help me out that would be great if not ill just have to do more reading.