ECMlink Higher than 100 on VE Table??? DSMLink

[Ludejim]

I think there is some information on these boards about this, although kinda scattered around. Ill try to keep it short.

I have 3 files:

1. Initial drive log
2. Modified SD Table
3. Modified Timing Table

I am concerned about the VE table, particularly numbers that exceed 100. I have heard that this may be due to my global fuel number and global dead time. If I am not mistaken you can change one or the other to fix this problem. Right now my global fuel is at -60.9 and my deadtime is 415 which is actually higher than what is recommended here. This is also slightly helpful. I Understand I should change the global fuel number to be closer to zero (less negative), but how much? I do not have a flow chart for my injectors

 

[BoostedBeaver]

I Understand I should change this number to be closer to zero

Which number are you refering too?

The global and deatime numbers listed on Link are great starting points but every setup will requier a little tweaking. Many factors including fuel pressure are to be considered when global and deadtimes are adjusted.

I can not see the logs at work but I will fire up the PC and take a look when I get home.

You also need to look at this link on Log File Advice. You will get more responses/help from very inteligent members of this board if you do as they ask.

Robert

 

[Ludejim]

Sorry, the global fuel number. The fuel pressure has been set to 37 PSI. Would lowering the global fuel number keep my VE numbers lower?

 

[white92talontsi]

Without looking at your log's if you are having to go over 100% on the VE table then you need to do more adjustments to your global and deadtime.

 

[BoostedBeaver]

Like white92talontsi stated, you more that likely have not correctly dialed in your injectors but again I can not see your logs at work.

Here is an SD guide that was made and posted here on tuners.

I Understand I should change this number to be closer to zero, but how much?

I am also still not understanding what you mean by this question.

Robert

 

[Ludejim]

Robert,
I have edited the first post, and here is further explanation. The global fuel number that is currently in my ecu config data is set at 60.9%. I am talking about making that number less negative, such as 57.9% or 50.9%. I just don't really know how far I should go with that global fuel number. Is the global like a course (large adjustment) and the dead time a fine (small adjustment)?

Also, I do believe that turbo chargers can and do create more than 100% volumetric efficiency. The question I have is how much, and when and how can you tell (without a MAF) that your VE cells are actually farther off than they should be. Right now the car is running halfway decent with huge numbers in the VE table while still hitting my numbers in the openloopmaxoct table. I think I am understanding the Speed Density table more as a general scale for where you have set your global and dead time.

 

[snowborder714]

You need to lower global % and then scale down your whole SD table (easiest using calan's LinkTools program).

 

[Ludejim]

Ok, I am actually using Calans tool. It works pretty well. That is how I came up with the VE table that I have now. I have also used the scaling tool to see what it would look like if I did change my global.

Would I also have to adjust the dead time?

 

[snowborder714]

Nope, just global %. You'll probably have to play around with it and try a few different values until you get one that hits your target max VE value.

 

[Ludejim]

And this might sound stupid, but how do you determine your target max VE value?

 

[snowborder714]

There's no real way. I personally shoot to keep my VE values below 105. So if I see a cell jump up past that, I'll go change it. But I also don't want my global % to drop really low, so it's kind of a give and take thing. You just have to monitor the car at the various time (idle, cruise, WOT) and make sure nothing goes out of whack when you change the global % and SD table.

 

[BoostedBeaver]

Sorry for the late reply and it seems that Snowboarder714 has really helped you out here and you should be good to go.

For further clarification on dialing in the global, I used a method that closely mimics the one in the article that I posted above. Of course, if you have already adjusted the airflow to counter the wrong fuel settings, the process will not work. If you decide to get a little more practice and start over the above article is very useful.

Hope that this gets you to boosting,
Robert

 

[Ludejim]

What I have been doing is kinda following the "How To Tune a 1G V3 SD ECMLink with no MAF" guide for idle tuning. While the car is running and I am watching the log I pay attention to the afr's, airflowperrev, and combined fuel trim. Adjusting VE table based on airflowperrev, and when it gets to ~.25 I will check combinedft and adjust my deadtime accordingly. Every now and then I'll take note of the wbfactor because it lets you know how far off yor afrs are. I'll go back and fourth until I have a solid idle making sure my afrs are at 14.7. Then I will take that log and run it through link tools and see what it recommends. So far this method has worked the best for me. Link tools can do so much, and you can get many different results based on the data that you select.

I attempted a fix for my other problem last night. So my turbo oil return setup doesn't work as well as I thought it would. I let the car idle for a little and checked for leaking oil. I didn't see any so I started to drive it. I got on the highway, and...well I am sure we all do the same thing when getting onto the highway. Pedal to the floor the holset kicked in at about 4000 rpm and we took off. Apparently, oil was shooting out of the return line for the turbo , everywhere underneath the car was covered. Realistically I should have lightly driven the car and checked for oil leaks, and gradually worked my way up to WOT, but this was the first time I really got to drive my car in the last year and a half. Anyways, I got some copper gasket spray from the auto store, made some new return line gaskets and coated them in the copper spray. I also RTV'd the bolts and got new crush washers. The RTV is drying, and then I will be able to drive. I think that I will start with the VE table that I had initially used to break in the car, while maintaining the timing table that I have modified for knock reasons. I also need a new battery, the one that I have will not hold a charge.

oh, I forgot. I found my flow chart for my injectors last night. 3 are 1140 and one is 1144, averaging out to 1141. So, according to link, at 1141cc and 37psi fuel pressure I should use a global of -60.6, when I run that through link tools it doesn't really end up making that big of a difference in my VE table. Should I run a higher fuel pressure or should I stick with the stock level? The flow chart also says at 13.5 volts it has a latency of 1.05 ms? If i convert that to microseconds for dead time I get 1040?? that seems a little high?

 

[snowborder714]

Your approach to idle tuning is correct, and the way I do it as well. I personally only use LinkTools to adjust WOT stuff.

Hopefully your oil drain is large enough (not sure what you're using). That's one way to kill a Holset quickly is to have a drain that's too small.

 

[Ludejim]

Yea, I am using the stock holset oil return for the turbo side with a 2g oil return line on the pan side with 3/4" I.D. silicone hose to connect the two.

 

[BoostedBeaver]

I think I saw Justin post something about beveling the 2g drain to help the oil flow but I can not seem to locate the thread.

Here is a video to fix the problem all together.

Holset Oil Drain

What I did not see in your tuning method is how you adjust your global? Do you just take the calculated global and plug it in??

Robert

 

[Ludejim]

What I did not see in your tuning method is how you adjust your global? Do you just take the calculated global and plug it in??

Robert

Yes, that is what I have been doing, and to be honest, it is what has worked the best for me by far. Although, now after reading through the How to tune a 1g on SD article I do see that it states:

If actual [AFR] is saying about 13s and [the AFR] estimates that you set in the OpenLoopMaxOct table are supposed to be 11.5s you need to change your global to get these babies to line up. If this is your case (the 13 and 11.5 example above) then you need to increase Global in the Fuel tab (or go in the direction that would ultimately be 0 Global, IE: richer).

Very important step that I missed. You and snowborder714 hammered that one home. I think I understand now.

 

[c2ypt1c]

Very important step that I missed. You and snowborder714 hammered that one home. I think I understand now.

If you're talking about doing this at idle while locked in open loop, then yes, this is a handy, quick method to get a rough estimate on global.

Otherwise

At WOT, you want to adjust global so that your max VE values are within an acceptable range, ie, 100-105 or so. If wideband and afratioest values are off (aka wbfactor), you adjust the VE table to line them back up. LinkTools does all of this for you. Have you watched Calan's videos?

http://www.dsmtuners.com/forums/ecmlink-tuning-log-file-advice/411083-ecmlink-linktools.html

 

[snowborder714]

You beat me to posting that same thing, Phil

I kept going over that quoted statement in my head and trying to figure out when it was saying to use that. As Phil stated, you shouldn't use global % to accommodate for mismatching AFR's during WOT tuning. The statement you posted hopefully had some other context around it in the original document that you just forgot to include. If it does say that in the WOT tuning section, then it needs to be corrected.

 

[Calan]

Is the global like a course (large adjustment) and the dead time a fine (small adjustment)?

No; they are totally different things. The global fuel parameter is a scaling factor that gets applied to the factory fuel calculations, based on injector size. A global value of "0" means "calculate fuel flow based on stock injector sizes". A lower (more negative) global value means "calculate fuel flow based on injectors that are x% larger than stock". Since larger injectors flow more fuel per a given amount of time that they are open, the ECU needs to calculate a shorter pulse width to hit the same target fuel flow. It uses the global value to correct those calculations, resulting in a shorter pulse width.

A lot of people have referred to deadtime as "injector latency" (myself included), but that isn't really what it is. A more accurate description for it would be an internal, arbitrary correction factor that is used to compensate for the operating delay of larger injectors. Since by definition deadtime affects the operating delay of the injector, it is most noticeable when operating delay makes up a large part of the total "on" time of the injector; in other words, at idle and short pulse widths. As pulse width gets longer and longer (more throttle, more fuel, WOT), the deadtime has less and less impact...since the tiny delay in opening and closing the injector is insignificant compared to the "long" amount of time that the injector is open and flowing fuel.

As Phil stated, you shouldn't use global % to accommodate for mismatching AFR's during WOT tuning. The statement you posted hopefully had some other context around it in the original document that you just forgot to include. If it does say that in the WOT tuning section, then it needs to be corrected.

Agreed.

You should adjust the global value based on your best information for your fuel setup, and then look at other areas (mainly airflow calibration) to dial in specific operating ranges. If you notice that you are rich or lean across all operating points after airflow calibration has been done, then small adjustments to global may be needed.

 

[Ludejim]

At WOT, you want to adjust global so that your max VE values are within an acceptable range, ie, 100-105 or so. If wideband and afratioest values are off (aka wbfactor), you adjust the VE table to line them back up. LinkTools does all of this for you. Have you watched Calan's videos?

Yes I have watched all of calans videos multiple times. Maybe I will go back and watch them again. I see now that you have to scale, pick and choose the variables that you know, and hopefully everything else will follow suite.

As Phil stated, you shouldn't use global % to accommodate for mismatching AFR's during WOT tuning.

Yes that is an interesting way to look at it. That is how I tuned it the first time, but was running 37 psi. I want full atomization and I want the injectors to flow at their known rates, so I changed my fuel pressure to 43.5 psi. I also made some custom VE tables to go along with a new idle rpm and a timing table that fixed a few knocks. The car started strong and idled great. I messed with the idle a little once it warmed up, but had to stop because my holset oil restrictor is to small and its not getting enough oil, and my oil return line that I had welded, had a bad weld so oil was skeeting out of it.

The statement you posted hopefully had some other context around it in the original document that you just forgot to include. If it does say that in the WOT tuning section, then it needs to be corrected.

Yes actually that is in "Step 9 - WOT tuning:" of this article.

 

[KFred 513]

Yes actually that is in "Step 9 - WOT tuning:" of this article.

I was thrown off by the WOT tuning part of that article too. Everything else I have read says not to touch global once you have idle/cruise dialed in.