VE Tuning

[alanwparkerap]

I'm having an annoying issue turning my ve table. So to start with when removing all the correction factors and setting up tune to use speed density only, disabling maf setting p0103 and p0102 to mil first error, disabling cot, decel fuel, long term fuel, ans o2 readiness. The factory was lean by 30% truck wouldn't even run. Anyways the first few changes I did made a huge difference. Now I'm close. In most areas only rich or lean by a few %. Now to my issue. I can not figure out how to produce consistency. If I use the same tune and record 3 different logs everyone of them are different. I take my eq error ratio multiply it by half and some things areas get closer while others get worse. What do I need to do to produce consistent values so I can be done with this. It's like I take 2 steps forward in some spots abd 5 steps back in others. How do I need to drive in order to get good results.

[alanwparkerap]

Also I have made another eq error table that uses a filter to only record when accelerator is more then 1% I did this to try and stop the decel from changing the values. For example. Tuck will be 5% lean on accel and 5 % rich on decel so it litterally makes that cell useless. I figured only recording the accel is more beneficial since I will re enable the option of going full lean on decel. I believe it is called dfco in vcm editor.

[LS ROB]

What i have found that worked for me was a minimum of 25 minutes of driving. Each time the VE cell gets crossed over, the number will change in your scanner. It either shows richer or leaner. All tunes will slightly vary from day to day via weather conditions. Im thinking your "tune" is consistent, but you aren't hitting the cells enough times for them to "show" consistent. Example; lets say you are 1.5% lean on a particular cell. You log a 15 minute drive and cross over that cell 20 times. The value for that cell in your scanner shows 5.5% lean. Now go for a 15 minute drive and cross the cell 80 times, your value would read closer to what your "actual" % is. It has to either learn up or down so to speak. Hope that makes sense.

*** The numbers I threw out there were just for example only.

[hjtrbo]

A few percent is where you stop. You have OCD .

You're that close that you're probably now been affected by interpolation between the cells. I don't know how anal you want to take your tuning? If to the anal limit, then set up the scanner differently. Include extra breakpoints between your rpm and map row / columns. You'll then have to copy paste into excel, tidy up and then can go back to the ve table. I presume since you're that close already you have good filtering set up and are aware of the rich after reflash gotcha.

In the screen shot I've only adjusted a couple of ranges to show what I mean. These are bounded by the red boxes. Within those boxes are the blue lines which are the actual data you will grab out of excel and apply to your VE table. By adding the breakpoints as shown, the useable data has been severely restricted to only a narrow rpm / map band.

Untitled.png

You will find this method:

• Extremely painful
• Frustrating dealing with shit loads of data in excel that you have to cut out
• Requires a lot more driving to populate the cells
• The table in the scanner looks a mess
• You have to keep using this method as when you revert the graph back in the scanner, the data may very well end up shit again in some cells because it interpolated and you might be more biased to one side of the breakpoint than the other

Maybe consider hiring some dyno time so you can tune steady state.

[alanwparkerap]

So to the first response. I figured that out the hard way. I was driving 15 minutes at first making changes and at first it made a big difference. But as time went on I saw short drives were hurting me more then helping so I actually only started using logs that were 45 minutes of driving and up. And I was wondering about the lean after flash thing. Turned out I knew without knowing. It got to the point where I would let truck warm up drive 15 minutes then stop turn truck off. Start it back up then do log. Now with the ocd. I am ocd. BAD. But my issue is a little more then that. When I make a change I find certain areas get better or stay the same. For instance my causing, staying under 2500 rpm is spot on .99 to 1.00 lambda. Now my issue is when I do sudden changes. For instance cruising around 60 and give it enough gas to down shift. Wide band spikes to around 1.15 then once shift happens drops down to the .99. Basically any kind if transient fueling. Also issue I'm having is idle. Let's say truck is at 210. We'll when I first put in park lambs is perfect .98 to .99. As time goes on it gets leaner and leaner. I can start idle at .98 within 10 minutes it is at 1.05. Filtering is at 25 hits. And like I stated in original I have a standard ve table in scanner that always records. Then another one that only records data when I'm on the pedal. Can I post tune and the 4 logs associated to show you the difference inconsistencies

[alanwparkerap]

Also I see what you mean with scanner. Basically instead of the 200rpm increments in the table I have now do 100rpm increments instead. And instead of only the normal 10 to 105 kpa at intervals of 3 maybe do increments of 1.5. Now my only question is what do you mean about cleaning up in excel? Is there a way to almost use excel to crunch the numbers down to where they line up with the ve tables?

[hjtrbo]

Obviously with the extra break points in the scanner you cant paste that in to your ve table in the tune. You can set up 2 sheets in excel. The first has your raw data from the scanner. The second has the break points as per your ve table. Inside the second sheets ve table you will have horizontal and vertical look up formulas referencing those same breakpoints on the first sheet. This will grab the matching breakpoint data and allow you to copy paste special into the ve table in your tune.

[alanwparkerap]

Anyway I could pay you @hjtrbo to help me. For instance send you the tune I'm running now and send you log to see if you can help me get spot on. Have already changed to 2bar so I just have to scale once I get turbo. I just want to be able to be within 2% without corrections. Preferably on the rich side since I floor it everywhere. I did the maf tuning. It took 5 logs and it was within 1% as of right now I'm at step 60 with ve tuning sad face. Ocd isn't even the word

[alanwparkerap]

Doing that wouldn't it jusy pull the same numbers. Or does the formulas somehow average the breakpoints so it matches the ve table in tune. Let's say my ve table in tune has 2000 2200 2400 rpm. And the scanner I set up has 2000 2100 2200 2300 2400. Let's say the scanner has the numbers 1534 1542 1550 1557 1600. Would it some how average the 2000 2100 2200 so it has a single value for 2000 and 2200 for ve table in tune?

[alanwparkerap]

Basically then using the 2100 value to average into both the 2000 and 2200

[hjtrbo]

I really wouldn't worry about. Switch the MAF back on and enjoy your ride.

[alanwparkerap]

Also quick question. If lambda reaches 1.1 at low rpm for short period of time it shouldn't hurt anything. Basically asking this. If I did something to mess up would I know. Like if the motor happen to run to lean would there be bad side effects or would I not know until it's to late. Since I was stuck I took the tune that was the closest to desired eq ratio through out and re enabled everything and put timing back. With that I reset long terms and so far I haven't seen more then + or - 5% except on decel. I have floored it multiple times and it seems good. Basically asking if I hurt motor. Or if it's good because it hits redline with no issue

[alanwparkerap]

Can you still take a look at these logs and tune to see if it is close? Also will you look at my ve table and tell me if it looks right or not. I Have already reenabled the maf and stuff but i would really like to get the ve spot on even if it takes some hassle i dont mind.

[Alvin]

Why are you logging so few things? Is it just because the logs are so long?

The error isn't bad. It could maybe be a little better but you got to realize you can't even feel the difference between a +5 spot and a -5 spot. I'll bet you'll likely notice that you can't tell a difference between tune revisions as the driver either.

This will never be perfect because a gas engine operating in different environment is a very dynamic thing. But it doesn't need to be perfect anyway. +/- 5%is usually pretty damn good for part throttle and +/- 2% is good at wide open.

also 1.1 lamda at low RPM/load isn't a issue at all. Lean is really an issue when it induces knock.

[alanwparkerap]

Only reason i log so few things is becasue i was told the less you try to record the more responsive it is. For example i thought if you logged a bunch of PIDS it slows the data rate therefore not being as accurate. My normal everyday log covers everything from engine to transmission, Honestly 50 + PIDS. Also did you happen to look at the differences between the logs posted? They were all done with no changes to the ECM and everyone of them show lean and rich in different areas. One more thing, Did you happen to open the tune and look at the VE Table and see how it looks. Im talking about the 3D Chart.