What you REALLY wanted to know about SOI.

Forward:
In light of the recent discussion(s) about different tuners and how they each handle various aspects of tuning (specifically, SOI timing control), combined with the fact that very few people have any real understanding of how the PCM calculates SOI, I am going to offer this information in an effort to clear up any of the mystery surrounding how the 7.3L PCM generates the SOI values. This thread is meant to be informative and educational, and as such is not the place to point fingers or start any type of battle between tunes/tuners from different companies. I WILL have moderators delete any posts that are neither a question, constructive, or informative.

Introduction:
In case anyone has any questions about my qualifications... We have almost 15 years of experience tuning the Ford EEC-V PCMs used in the 7.3L and created most (if not all) of the 7.3L calibrations that were available in the US until 2001, at which point TS Performance, Bully Dog, and a few other small companies became involved with the 7.3L chips and tuning. In 2000 we were the first to offer custom tuning for the 7.3L for modified injectors (actually, we tuned for modified injectors as far back as early 1999), compound turbos, and other mods. We have written and/or contributed to most of the 7.3L tuning tools and software that is (or has been) used by most of the popular tuners including Gearhead, Swamps, DP-T, BTS, Tyrant, TDP (Tony), and Bean's, as well as being used by Brian Jelich and Mike Ontiveros. We have the only 7.3L simulation software that will accurately provide output maps of SOI, ICP, and PWM as the PCM would calculate them. We also have the only diagnostic equipment that can correctly log actual SOI values from the OBDII port, which we have used to substantiate the graphs generated during PCM simulation. We have used real-time emulators to trace and follow the PCM functions to determine how each function/map inter-relates with other functions/maps. We have dynoed and CP-tested a variety of engine/injector configurations and not only have a solid understanding of how the PCM functions to generate SOI, but also how SOC (Start of Combustion) is related to SOI, ICP, EOT, Boost, Injector configuration (Split, Single, Hybrid, etc.), and Injector nozzle size.

Overview:
The purpose of this thread will be to provide clear, concise examples of how the PCM generates the final SOI values which are sent to the IDM and ultimately the injectors. We also plan to provide a clearer picture on how the relationship between tuning and specific modifications can affect SOC. We will be providing substantive graphical data (maps) to support our findings and will welcome any questions, either in general, or about any specific data we provide. All graphical data provided will be from either completely stock calibrations, or from calibrations in our own library. We will not be providing graphs of the actual tuning maps themselves, as this may only cause confusion if they are not properly assessed in relation to other maps. We, instead, will provide the calculated output graphs generated through our simulation software and we'll be happy to consider other data requests. We will not be posting any actual tuning graphs from a competitor's product without first receiving authorization to do so, so DO NOT ASK unless you have authorization. However, if anyone has a file they'd like analyzed we will consider posting the calculated values generated by the simulation software.

That's about it. I'll start posting the graphs and other information shortly.

Stay tuned...

:fordoval:

Bill you couldn't have said that any better.. cant wait to see more. I definitely want to understand more how these machines work and I'm sure plenty others here as well, much appreciated.

Not to be pushy... Can you tell us how you guys tune the PMR motors differently that Forged Rod motors? Thats all I really care about.

I'm watching and eager to see what is posted and hopefully some good discussion can come about.

I'm in on this one never quite understood the tuning but would love to get some insight on how everything is generated by the PCM. What some tuning no no's are. Would eventually like to tune my own truck...

Great Bill, and just to confirm - All mods will be watching this - Anyone starting crap in this thread, post will be deleted and if deem needed, a vacation will be given....

.

:whs:

This can be a very informative thread, or it can go way off track really fast. I vote for the informative.

Part 1: The Software

Part 1: The Software:

Okay, so where to begin? One would normally say, "At the beginning..." but I'd think that would involve a great deal of boring tuning history. Well, maybe that really is the best place because without some of that history, some of this might not make any sense. LOL

To start off, I will say is that tuning has come a LONG way from where we started back in 1997 when I was working at Superchips, and we literally had almost no idea what it was we were changing. The tools we had back then offered no graphical interpretation of the data we were changing. We didn't even know what the actual engineering values were of the data we were changing or whether it was a fuel map, a timing map, shifting map, or a limiter. It was all "HEX" data in its purest form and we were making changes with the attitude of, "Hey, let's change this and see what it does!" We were hackers in the purest sense of the word. (Butchers might have been a more appropriate word!) Below is a screen shot of the first tuning software we used:



As you can see, it's not only just a bunch of numbers, it's Hexadecimal numbers. And to make it worse, 16 bit maps like this were viewed in 8 bit formats and the bytes were reversed (what we call "Little-Endian"). But as I said, this is what we had at the time. Although, somehow we made it work. For reference, this is the Oil Viscosity Compensation table that controls injection pulsewidth based on EOT and ICP.

From these early beginnings, using archaic and almost neanderthal tools, we were able to locate and identify enough calibration data to make 60-70 HP on the OBS trucks and over 100 HP on the S/D trucks. We were also able to locate enough shifting data to significantly improve the shifting characteristics, although it's not like ANYTHING that we have today. Early tuning was almost brute force. Sort of like using a sledgehammer to open walnuts. It was effective, but maybe a little too much. Anyway, this was how it was done for over 4 years. That is, until something better came along.

2001 saw the introduction of new tuning tools. The first was a software tool called GUI EECTuner. This was actually the predecessor to the SCT Advantage software which was written by David Posea, and offered the first definition format which stored the address and scales of maps, parameters, and functions, and allowed for an accurate, 3D representation of maps. For the first time we were able to actually produce some sort visualization for the numerical data. I had actually used this software to some extent, and while the 3D graphs weren't all that fantastic, it was better than nothing.

Shortly after the introduction of GUI EECTuner (mid 2002 or so, I'm guessing), I had come across a website that offered a different tuning software package. The website offered an application that was completely focused on high quality, 3D representations of the Hexadecimal data. The definitions were completely customizable and all the graphical data was scalable. This software was PCMX, and is what nearly all of the Ford tuning industry has been using since 2003. Now, this software was originally targeted for Gasoline tuning, and a number of definitions already existed for Mustangs, early F-Series trucks, and other Gasoline vehicles. However, there wasn't anything yet available for the 7.3L diesel. It wasn't until 2003 that we stared taking the data we had accumulated and began building and refining defintions for the Power Strokes. We spent several months developing these definitions and just about the time that we had started licensing PCMX and selling the defintions, I was offered a job to go work with Edge Products out in Utah. At this point, basically all development on the PCMX definitions stopped. Edge had orginally intended to support all our exisiting customers and dealers, but unfortunately they let all that fall by the wayside.

Somewhere around the same time that I went to work for Edge, SCT (Superchips Custom Tuning) had been formed as a branch of Superchips that dealt specifically with custom tuning. The idea was that SCT would provide their sizable software and calibration base and Superchips would provide the hardware. Unfortunately, the joint venture quickly soured and SCT broke off and continued as their own entity. The reason this is important is that at this time, SCT started releasing the first large-scale tuning application that offered 3D mapping, spreadsheet style data, linked mapped transfer functions, and integrated support for chips and programmers. Being built on the GUI EECTuner platform (or at least modeled after it), this software still lacked the high quality 3D mapping that PCMX offfered, but since SCT offered already built, custom tunes it wasn't really necessary for anyone to actually do their own tuning and the graphical data wasn't all that important. At least nobody seemed to think it was at the time.

Now, you're probably wondering, "What's so important about 3D mapping and why do we need now all this?" On the surface, it doesn't seem like it's all that big a deal, but the reality is far from that. One example of the importance of 3D mapping is very apparent in the following images:

(click to enlarge)


The map and data on the left are an implementation of an SOI table we pulled out of an early chip from an unnamed tuner (and NO, it's NOT DP-Tuner... in case anyone feels like being a smart-alec) while the right calibration is an implementation of one of our own 80DD tunes. Looking at the spreadsheet style data, it may or may not be readily apparent that the mapping on the left is not smooth or linear. However, looking at the graphical map shows how jagged and uneven the left map really appears. By comparison, the map on the right shows to be much smoother. On top of that, the left map also shows to be really aggressive in the upper RPM range, although the spreadsheet does show the timing is aggressive as well. In any event, it's MUCH better than original way we used to tune which provided no real idea whatsoever of what the values were, graphical or otherwise. :doh:

Since the release of PCMX and SCT software back in the early 2000's, there have been a couple other applications that have been released that offer tuning in a 3D graphical format. Applications such as Paul Booth's EEC Editor (available from Moates.net), EFI-Live (which currently does not support Ford, but has a very usable interface), and a few others that escape me at the moment. The tools are getting better and better.

One thing I haven't address yet, but will in a coming segment, is how we use the calibration simulator to generate the output mapping which shows us the SOI Timing and Fuel PW curves we use to refine our tuning. This can be pretty in-depth stuff since it not only deals with the generated output, but also the order in which the data is processed to generate the output values. We feel that this needed its own segment due to the complexity of the processes.

Anyway, I hope that this information is helpful and gives you some idea as to why tuning today is considerably different than tuning that was produced back in the early 2000's. As the tools have evolved, so has the tuning. Of course, having the proper tools doesn't guarantee that any given person would know how to use them. There is still the issue putting the software in the hands of people that really understand how to use it; Individuals that have a solid understanding of how an internal combustion engine (either gas or diesel) works and how each of the maps interrelate with each other to produce the anticipated output values for fuel, timing, shifting, and other functions, and how those outputs will affect the functionality of the engine. Thousands of mechanics use Snap-On tools, but only a few are talented enough to work on an Le Mans, NASCAR or NHRA race team while others I wouldn't let change the air in my tires.

__________

Coming up next... Part 2: The tuning hardware. Dynos, testing equipment, emulators, and how they all work together.

Stay Tuned!

Awesome stuff! It is very interesting to know how far tuning has come in the last decade.

Very interesting stuff here, and a good story. I know where SCT came from now.

Bill,
Thank you very much for sharing your expertise on tuning with us. It's definitely eye-opening and a joy to read and learn. Hopefully, this will put some of the trash and bash threads to rest.

Let's get some posts rolling with some more info and some actual discussion - as of right now there is literally one useful post and a whole lot of watching.

It would be fantastic if other tuners and guys with understanding of how this system works were to pitch in their two cents along the way and get a discussion going.

For instance - I have a little experience with PCMX, a bit more with Minotour, I've looked at the early SCT stuff out at WipeOut, and spent some decent time playing with EFI-Live. So I have a vague ideas on how some of the tables should interact, but like all things that have evolved some of those tables that we thought we knew what did - actually don't do it how we thought it did.

I'm waiting to see where this goes and contribute if needed but Bill probably has this all wrapped up already.

Hotrodtractor said:

Let's get some posts rolling with some more info and some actual discussion - as of right now there is literally one useful post and a whole lot of watching.

It would be fantastic if other tuners and guys with understanding of how this system works were to pitch in their two cents along the way and get a discussion going.

For instance - I have a little experience with PCMX, a bit more with Minotour, I've looked at the early SCT stuff out at WipeOut, and spent some decent time playing with EFI-Live. So I have a vague ideas on how some of the tables should interact, but like all things that have evolved some of those tables that we thought we knew what did - actually don't do it how we thought it did.

Click to expand...

Jason,

Hang tight just a little longer until I can get all the information I wanted to present posted, and then we can begin picking things apart and getting more in-depth. I just don't want to get into a situation where I am answering questions that may very well be answered in my posts. Just give me another day or so to finish out my thoughts and we can go from there. Cool?

Gearhead said:

I'm waiting to see where this goes and contribute if needed but Bill probably has this all wrapped up already.

Click to expand...

Matt,

I'd be thrilled to have input from other competent, experienced tuners. However, like I asked Jason, if we can hold any input until I've had a chance to get the rest of the posts up, that would be great. I just don't want to get sidetracked just yet.

Next post to come shortly. Dinner calls!

Power Hungry said:

Jason,

Hang tight just a little longer until I can get all the information I wanted to present posted, and then we can begin picking things apart and getting more in-depth. I just don't want to get into a situation where I am answering questions that may very well be answered in my posts. Just give me another day or so to finish out my thoughts and we can go from there. Cool?

Click to expand...

I'm totally cool with it - that is why I didn't really list any examples that may or may not have taken away from your explanation. Carry on.

Power Hungry said:

Now, you're probably wondering, "What's so important about 3D mapping and why do we need now all this?" On the surface, it doesn't seem like it's all that big a deal, but the reality is far from that. One example of the importance of 3D mapping is very apparent in the following images:

Click to expand...

Very informative!

And I can second the use of 3d mapping. I used it all the time when I used to tune LS1's and LS2's. I used HPTuners which had what I thought was a very good GUI. Logically accessable tables and the ability to plot 3d maps made tuning fairly straightforward and kept tables smooth. Transitions between different tables for fueling and spark states took a minute to figure out, but in the end a little experience went a long way.

Are there seperate fueling, SOI, etc. tables in the Diesel world like in the gasser world?

CamTom12 said:

Very informative!

And I can second the use of 3d mapping. I used it all the time when I used to tune LS1's and LS2's. I used HPTuners which had what I thought was a very good GUI. Logically accessable tables and the ability to plot 3d maps made tuning fairly straightforward and kept tables smooth. Transitions between different tables for fueling and spark states took a minute to figure out, but in the end a little experience went a long way.

Are there seperate fueling, SOI, etc. tables in the Diesel world like in the gasser world?

Click to expand...

Yes.

Charles said:

Yes.

Click to expand...

Short answer, LOL.

I meant different tables for different states for the same parameters. I think you knew what I meant but when I re-read my question this morning it wasn't very clear.

CamTom12 said:

Short answer, LOL.

I meant different tables for different states for the same parameters. I think you knew what I meant but when I re-read my question this morning it wasn't very clear.

Click to expand...

I was just trying to handle the question so that it didn't sidetrack Bill. He said he wanted to get everything out before getting sidetracked.

If you're referring to separate sets of maps for things like WOT, then yes. There are specific parameters for controlling idle fueling for instance, aside from the actual fuel maps themselves.

If you're talking about trims for things like temp, then yes as well. Although I would wager that compared to gassers, the extent to which extra bs tables exist that aren't needed will be significantly reduced in comparison.

Charles said:

I was just trying to handle the question so that it didn't sidetrack Bill. He said he wanted to get everything out before getting sidetracked.

If you're referring to separate sets of maps for things like WOT, then yes. There are specific parameters for controlling idle fueling for instance, aside from the actual fuel maps themselves.

If you're talking about trims for things like temp, then yes as well. Although I would wager that compared to gassers, the extent to which extra bs tables exist that aren't needed will be significantly reduced in comparison.

Click to expand...

No worries, I was curious and got my answer! Thanks!

Looking forward to Bill's next installment!