90FormulaPROJ

I just downloaded this file Super_8dm2.ecu. Is this a good file to use that I can trust? Also I was looking threw all the diff things and I came to this one table which was called "Enrich Power Change to AFR Vs. RPM". How do you make it richer or leaner? Does making it -2.34 cause it to run leaner or richer? Also I noticed after doing alot of searching that I don't have all these tables people are talking about. Here is a screen shot of all the tables this ecu files has.

Tables

Does anyone notice it missing any tables? It seems the only thing I can edit for AFR is just that one table I mentioned earlier.
Thanks
Shawn

1320 Right Ln.

um... i think you need to do a bit more research/reading. the volumetric efficiency table is what you're looking for. That .ecu file has it misspelled. Anywho, one of the main aspects that make Super_8dm2.ecu great is the extended VE table that goes to 6400 rpm. What does that mean for you? fuel control for RPMs in excess of 5600... where the original 1227730 ecu cuts off. Hence the reason that you see two separate tables for the same thing...or sorta the same thing anyway.
Modify the injector PW, and you modify the AFR.
As for the table you mentioned, those values are given in percentage form as opposed to direct VE. the bigger the number, the more fuel it adds and vice-versa. Through various calculations, the ecm will derive a final PW for the injectors based upon the values you set in the VE tables and inputs from the engines sensors, like coolant temp. When the ecm goes into power enrichment, that table you mentioned get's thrown into the mix to further modify the final PW that goes to the injectors.
It's really late, I'm feelin kinda dizzy, and I got class tomorrow/later this morning... so i think i'll stop.

90FormulaPROJ

How do you adjust the Volumetric table to richen the mixture?
Why is it better to use that table over the AFR vs RPM table?

JP86SS

iTrader: (1)

Increasing the values in the VE table adds more fuel.
By changing these values your combination of transmission, gear ratio, car weight etc are adjusted so the motor makes the best power where it needs it without the BLM adding or subtracting the required fuel automatically. There are notes in the stickies so look in there for some good help on how to go about it.
Then you can begin to adjust the spark table and get the power really going. These are the main 2 that will give you the setup to make the car/motor combination work correctly.
Then you can move on to that WOT pull and adjust for the PE "power enrichment" and AE "Accelleration enrichment" to get it jumping when you mash it.
There are many other aspects to this and this just is a very rough outline. Each of these items interacts and will make you readjust what was once perfect, so be ready for it.
It's alot of fun and you will be pleased with the results if you do your homework and lots of stickie reading.
Good luck.
Jp

1320 Right Ln.

The stickies do contain a wealth of information, but I wouldn't recommend it as a starting point if you want to learn this EFI stuff. It's relatively unorganized, with some advanced stuff randomly thrown into the mix... and if you haven't yet mastered the basics of how the ecm operates, it may as well be in greek. I learned a lot from this board, but it took me a while, as it does for most people - ya just gotta dive right in and read what you can.
I would like to suggest that you check out the tuning manual for the Holley Commander 950 system as a starting point... the operation of the Holley system is nearly identical to the MAP systems found in GM ecms. That'll give you the basics: what sensors do what, why they're important, when does the computer look at this specific sensor and why, closed vs open loop, what factors come into play in determining a final injector PW... and i like how it breaks things down into different states of the motor. It's a logical progression from the most basic of basic, to WOT.
You start with Cranking settings
then Idle settings
Part throttle
Accel Enrich
WOT/Power enrich
The factory ECM controls a lot more stuff than the Holley system, but if you understand how the Holley system works, then you understand how to make the car run... the other stuff GM put in there for auto trans controll, emissions equipment, Fuel economy settings and various other useful bits (Although the engie can run fine w/o them).
anyway, here's a link:
http://holley.com/HiOctn/TechServ/TechInfo/R10149-5.pdf
I recommend that you d/l and print that to make it easier to read.

JP86SS

iTrader: (1)

Like we said, lots of reading to get the basic understanding of what you are adjusting.
I've always liked this site for it's info.
http://chevythunder.com/
there's alot there to get you to understand the parts.

90FormulaPROJ

Do I have to tune in this order? I just got the APU1 and I want to go to the dyno and tune it. But from what I am reading I have to tune it part throttle first. The car runs fine part throttle. I just wanna make sure the AFR is correct at WOT. Will tuning the spark table make that big of a differance? How do I know I can add more spark? How do I know when I need to take some out? I have a basic understanding from all the reading I have done. I just don't understand what tables do what. I see that the most important thing for AFR is your injector PW, ie how long your injector stays open. What is the formula the computer uses to get its PW time? Do I have to change multiple table just to richen WOT? I wish someone had a simplified training guide for this. You are definately right about it being confusing.
:lala:

1320 Right Ln.

if you're lucky enough to be able to dyno tune the ecm, then by all means tune WOT first if you want. To learn what tables do what, you can check out the item comments in tunerpro.
For the most part, you wouldn't want to mess with a lot of the tables... like i completely ignore the crank fueling stuff, BLM cell boundries, low octane stuff, knock stuff (motor never knocks anyway). Those kinda tables you should never have to mess with really - maybe in rare circumstances of extreme cylinder pressures would you want to mess with some crank fuel and spark tables/modifiers.
everything labled TCC controls the auto trans torque converter, as you've probably figured out... just read the name of the table, and it's purpose is clear.
don't worry about the MAT stuff or EGR

using the dyno privilages you to a WBO2 sensor, so for WOT, just make a note of your AFR at various RPM's and adjust the VE table accordingly to obtain your desired result. Practically all aspects of how much fuel is injected at any given time can be adjusted via the main/extended VE tables, because the table encompasses every RPM-Load variation that the motor will ever see.
Running lean on the top end? Say you want an AFR of 12.5:1 @ 5200 rpm with a MAP of 98 kPa...the WBO2 is reading an AFR of 13:1. Go to the VE table, find the cell where 5200 rpm and 90 kPa intersect, then bump up the value to get more fuel...then you gotta smooth out the cells around it - easiest to do in the graph window i think.

As for the spark timing, different people have different opinions. Some people suggest putting in as much timing as possible until you get knock, then take out a couple degrees to be safe (only in WOT areas). You again have the luxury of using a dyno, so just see what works best for you... the generally accepted range for max power is between 32-38 degrees total coming in by about 3000 RPM. The total timing that works best for you depends on how efficiently/quickly your gas goes boom. The better the combustion, the less timing you need.

90FormulaPROJ

In the VE table upper to 5600 what do those numbers mean? They are like 75-99. What do they represent? Can I not use the AFR vs RPM table to make a change? It seems alot easier.
Thanks for all your help guys. I appreciate someone sharing their knowledge.
Shawn

thirdgen88

That table is for Power Enrichment mode. You need to fix the standard VE table first before you change other fuel calculations.

90FormulaPROJ

fix? What am I trying to fix here?

1320 Right Ln.

here's something you might find interesting. my dad bought a level V tune from TPIS $575... ouch... but i used my PP2 to read the chip a while back and found the PE change to AFR vs. RPM table was completely zeroed out. They did the same for PE Spark vs. RPM. The PE change to AFR vs. temp was left at the factory AUJP settings. Basically that means that TPIS decided to tune the fuel curve completely via the VE table, without any rich/lean modifiers when in PE mode except for temp correction.
This makes total sense too... i mean really, the only time you'll ever be in the high load (kPa) areas is at WOT, which puts you in PE anyway. So TPIS just calculated the engines volumetric efficiency, put it in the VE table/s and left it at that... if there was even more fuel being added under PE, then the mixture would then become too rich... and at the top end it'd be too lean, as the stock tune takes out fuel at the high rpm.
Same concept for the spark timing PE table, just set it to zero cuz you can just tune it from the main SA table.

90FormulaPROJ

That is interesting. I just don't understand the purpose of the VE table. What is VE? How is it used to calculate AFR? AFR vs RPM is understandable being in a simple percentage. But the VE table is a weird number. What does this number represent?

1320 Right Ln.

what's ve n' how is it used...... that could be the title of a big fat book. let's start with the basics, AFR is a ratio of how many parts of air combine with one part of fuel right? stoichiometric being 14.7 parts air to one part fuel. i think you'd agree with that.
Each cylinder is limited to how much air it can hold (assuming no forced induction). say the volume of a cylinder is 713cc... w/o forced induction, the most air that cylinder can hold is going to be 713cc's (for the most part). Volumetric efficiency is just a percentage of how much air the cylinder CAN hold vs. how much air is actually in it. So, at 100% VE, a 713cc cylinder will contain 713cc's of air...50% will be 356.5cc's etc.
Now, the cylinders get filled with varying amounts of air depending on rpm and map. it's obvious that the cylinders are going to be full of more air at 5000 rpm @ WOT, than they are at idle.
The ecm will use the percentages in the VE table to determine how much air is filling the cylinders. From that, the ecm will then determine how much fuel is required to obtain the desired ratio of air to fuel.
The PE tables you first mentioned are modifiers. After the ecm gets it PW from the VE table, it'll be further modified by the PE tables before reaching the final PW that goes to the injectors. For WOT, you'll want a lower AFR right? so the purpose of those PE tables is to add more fuel when needed. What TPIS did, was put in values for Volumetric efficiency that would result in a richer than 14.7:1 AFR in the areas of high MAP/load. Since those areas of the table are already modified for a richer mixture, there is no need for further modification from the PE tables.

90FormulaPROJ

OH I see now. So basicly using the VE tables to tune AFR is a more accurate way of doing AFR for WOT. Seeing that you can adjust for certain map values instead of just PE rpm. Both will work for adjusting AFR. But the problem I see using VE tables instead of the PE AFR vs RPM is this, say you set the values for the PE vs rpm to all 0, now when you go into PE mode you have lost fuel to all the other none WOT situations. So now you have to retune the ALL the VE tables not just the high map ones. This could screw up my drivability. But then again if I tune WOT with the PE vs RPM table it also could effect my driveability based on the fact that now i get more fuel at a part throttle PE situation. HMMM which is the lesser of 2 evils. What I might do is bring the high rpm in the PE table to 0 instead of -2.34 and leave the rest alone. Then just adjust the values in the VE table to add more fuel. That way everything stays the same accept a high rpm high map value. What do you think? My head hurts!
Shawn

JP86SS

iTrader: (1)

I think you're starting to see the light
there's more than one way to skin these cats and it's just a matter of how YOU want to go about it.
You see the interaction of PE AE with using them with a good drivability on the "normal" VE table. Or you can do away with the modifiers and just tune it to runthe way you like.
There is also the option to just run open loop all the time using the VE table and make it run without automatic fuel correction from the O2 sensor.
Lots of ways, each has difficulties and tuning issues . Just have to find what you like to do and what works for your combo.

90FormulaPROJ

2 questions. Can you take the values in the ve table to over 99? In the extended VE table that goes to 6400 all the values are 0, do I just fill in the values that are 5700 and above? If I rev over 5600 will i HAVE to fill in those values?

RBob

iTrader: (1)

If the values in the 6400 RPM VE table are zero's, then I'd say the extended VE table patch is not in place. IOW, the ECM is using the standard VE table (the one that goes to 5600 RPM).

There is a patch that needs to be applied to the bin in order to use the extended VE table.

Of course the next question will be where do I get this patch. . . Hmm, it may be on Moate's site. I recall the source for the patch being posted here, can't remember if the .s19 and such is else where.

RBob.

1320 Right Ln.

I've never used a VE value above 99 before... i'm not sure if you can go higher or not. I figure you could use a higher value, the equation the ecm uses isn't limited to numbers less than 100%. However, for the most part, you won't get VE values over 100% w/o forced induction n' i just noticed the lil procharger logo in u're avatar. If you're using a blower on the motor u're trying to tune, then the 1227730 ecm is not what you would ideally want to use. Notice how the load/kPa table is limited to 100. Atmospheric pressure around the engine is gonna be between 95-100 kPa, that'd mean no vacuum in the manifold, nor any boost... that's the highest most non-blown engines will see right? The MAP sensor and ecm equiped in your car is only designed to meter the amount vacuum, or a lack of vacuum, but not boost. Once u're blower starts to produce positive manifold pressure (kPa over 100), the ecm won't be able to compensate with more fuel cuz it duzn't know what boost is.
Some people choose to use the 1227749 ecm from a GMC syclone/typhoon with the appropriate MAP sensor. Those can accomodate the added fuel needs of positive manifold pressure. There are other options too, that's just one of 'em.
You can use the blower on the 730 ecm, it's not like it's gonna freak out n' short circuit... it's just that you lose the ability to tune the boosted parts via the factory ecm.
I've never worked with forced induction, so i don't know a whole lot about tuning that stuff, but there's a few experienced people on this board, maybe you can check out the forced induction forum and see what they do.

MikeH

iTrader: (10)

This is a great thread.... things are starting to make sense to me. I spent the day tuning and she is finaly starting to show her stuff in part and wot.