Im running a 6E mask based bin and was wondering what is the preferred method for adjusting the part throttle fuel delivery to get the BLM close to 128.

 

Perferred, or correct?.
The EZ, way which lots of folks seem to perfer is just juggling the injector constant until things seem about right.
The correct way, is actually using the MAF tables. This accounts for reversion, and gets the calibration dead on, as opposed to about right.

 

So when someone sets their injector constant to a slightly leaner setting than their injectors... IE ... 24lbers set to 25ish...... And they are at 108blm across the board.....

That you should play with the maf tables to accomodate that? Those are some big changes with the tables, and almost seems like lying to the ECM.


__In my case I have a theory that the larger than stock cam doesn't pull as much vacuum as stock, thus raising fuel across the board. That or the HSR regulator isn't in line with a stock one



I do think Grumpy is right, start with your maf tables..... Idle... cruise at what says 20grams/sec, 40grams/sec..... adjust those values to good blm, then use the graphing function to raise the rest in a linear fashion.

I've just started to play with my MAF tables and I have my injector constant set to 36lbers when I've only got 24! 36 got it in the ballpark, but not where I want it. Seems like lying about ones injector constant is worse than lying about the actual incoming air...

 

BTW I get much more response in BLM from adjusting the MAF tables a little bit, than the injector constant ever did.

 

So you are saying that the correct method for blm correction in 6E would be the maf tables?? Not to bring up a sore subject but how did that go from blowing your engine up to the correct method?


Tim

 

It's been a big debate, and one would think if you get the desired results you've done it correctly.

Everyone has their own tools and methods.

 

understood.... But a couple of years ago I was looked down at for using the maf tables. But if grumpy says it's right ,then I'll be happy cause I always thought it was the ONLY way for 6e blm correction....

 

I am a bit surprised that you would bring this up.

Over the years as more is learned new techniques are developed. It is easy to get into trouble when dealing with MAF tables. As long as the person making the changes understands their operation then it works as intended. When that person does not understand their operation, it can get ugly.

Even myself, I only learned how the MAF tables and scalars operate a year or two ago. Up until I went through the code and understood what GM did, I would not have been able to rescale the tables correctly.

RBob.

 

I hope it's not a bad thing. For me, the maf system has been a journey. I even fought myself to modify some settings. I have learned how some of the code works. Even though assembly language is beyond my grasp. I always used the maf tables for blm correction. Once I was told it was wrong I didn't stop. I wanted to understand why using them was wrong. And I started to wonder how/why the ecm works. The more I learned, the maf tables seemed to be correct. It's kind of embarrassing cause if you search my old threads you can see everything.



I agree, the maf tables are for fine fuel corrections. A noob could rescale the tables lower and damage something. I would consider the same for the ve tables.

I learned how to adjust the tables before reading the code. I would use log data to determine what the tables do. I still have some questions about the maf tables. Could you help explain a few things to me?

 

In overall functionality the MAF tables are similar to the VE tables. In how they operate they are more complex then a VE table. It is this complexity that can be difficult to understand.

There are a couple of things to keep in mind when working with the MAF tables. If the last entry of a table needs increasing then the scalar for that table will first need to be changed. Changing a table scalar changes the gms/sec value of every entry in that table. Now every table entry needs to be re-calculated and changed in order to keep the same end value.

Now the last table entry can be updated. Of course this means that the first entry in the next MAF table should be changed. This is because the MAF tables are contiguous.

The flip side to all of this is if you need to change a couple of entries in the middle of a MAF table by a couples of gms/sec, no problem. Make the changes and go. Just have to be careful to not get a false sense of security that the MAF tables are easy to work with.

RBob.

 

I totally agree. I was hoping you could explain a few thing that I've been wondering. I guess I can just PM you...

 

I'm using CATS tuner and where do I find the option for changing the table scalar. I can only find a scale option under the edit menu.

 

Not sure why a PM is required. I've always answered questions whenever able. . . Tim, if your question isn't DIY PROM related then feel free to PM.

RBob.

 

An email to TunerCAT may be best. They are typically prompt in answering questions about their product and/or a TDF.

RBob.

 

I didn't want to hijack the original poster's thread. It is diy-prom related. So I guess I'll just start a new thread. Thanks

 

Also wondering where it's at in tunerpro since I have used that as well as CATS.

 

By scaler, are you all refering to something separate than the 6 MAF tables available for editing? Or do you mean that when you change a single volt output in the maf table significantly, you need to "scale the table" to keep the graph in a linear fashion?

 

Newb question:

What's BLM stand for?

 

Block Learn Multiplier

 

Someone explain the scaler thing?! ^^^^^^(see few posts above)

 

Can you elaborate? I don't want to hijack this thread but maybe just a brief explanation? Thanks

-Corey

 

The BLM makes air/fuel adjustments based on the int, When the int strays from 128 (nominal value) for a period of time, the BLM will make "coarse" corrections to the A/F delivery to try to get the int back in line.
As described, the Int reacts to O2 readings and the BLM reacts to the int, trying to keep the A/F carefully balanced.