Load calculated?
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Joined: May 2008
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From: Colorado
Load calculated?
So before I beguin, I have searched, I come up with alot of results, nothing helpful!
Just wondering exactly how load is calcuated inside the ECU for reference on the maps? I know you can log the 2 byte load, and it references where in the map you are, but if I"m not mistaken, that's just based on the commanded AFR, so we're essentially looking at where we were instead of where we're going.
Right now I'm dealing with a 3G GS eclipse, 4cyl, turbo'd, but it's an 02. The problem I've found with the 02 is the deffinition isnt' complete, and neither is the logging. I can't 2 byte mod it, I can't change MAF trans.....about all I can do is screw with the fuel map, and making this thing understand boost seems a bit difficult, since I feel like I'm flying blind. Now I'm used to SD tuning where a load column equals a boost level, and it's really straight forward and simple. But this doesn't seem so. I'm adding fuel (where I think it should be) but in the higher RPM, no matter what it seems to run lean. So finally I screwed with the ign values, gave each cell a different value (all safe though) and made a pass. Now it's hard reading the EvoScan log since I get all of 4 plot points for an entire dyno run, but from what I gather the load isn't staying in one column, not even close. Just reving it in neutral I'm hitting ~80%, but under 5psia of boost at redline it seems as though I'm climbing BACK to 40-60% load. So there's more load when I've reving it in neutral than at 5psi redline? Comming from speed/density this doesn't make any since, but I'm guessing that it's a function of airflow vs engine speed or something? But even then I don't see how airflow/rpm from no boost could match or exceed that of boost?
So then what exactly is defined as 100%?, and what happens if I exceed that? I mean if this was designed as an NA ecu, than 100% I would think would be a little above that as defined as max airflow at sea level with ambient pressure? I'm sure the ability to log correctly, or maybe even manipulate the MAF trans would make this so much easier to tune. But I'm past the point of it being hard, now I'm just trying to understand how/why it works and how that load number is derived? I mean 100% is great, but 100% of what?
I mean if it was based off throttle 0 = closed, 100 = open. MAF flow 0 = 0, 100 = (you'd have to know the peak i guess). But this number seems to be going down as the flow increases.
Now Honda is SD, easy. Ford, Sub, and some chevy seem to use a defined load of g/cyl or g/sec, or g/cyl/sec or some DEFINED variation there of. Some chevy does use a LV8 term, which I still don't understand either, but it at least seems to be a little more predictable and constant than on here.
Any help or thoughts would be great, I'm just trying to understand the thinking behind all this.
UPP
Just wondering exactly how load is calcuated inside the ECU for reference on the maps? I know you can log the 2 byte load, and it references where in the map you are, but if I"m not mistaken, that's just based on the commanded AFR, so we're essentially looking at where we were instead of where we're going.
Right now I'm dealing with a 3G GS eclipse, 4cyl, turbo'd, but it's an 02. The problem I've found with the 02 is the deffinition isnt' complete, and neither is the logging. I can't 2 byte mod it, I can't change MAF trans.....about all I can do is screw with the fuel map, and making this thing understand boost seems a bit difficult, since I feel like I'm flying blind. Now I'm used to SD tuning where a load column equals a boost level, and it's really straight forward and simple. But this doesn't seem so. I'm adding fuel (where I think it should be) but in the higher RPM, no matter what it seems to run lean. So finally I screwed with the ign values, gave each cell a different value (all safe though) and made a pass. Now it's hard reading the EvoScan log since I get all of 4 plot points for an entire dyno run, but from what I gather the load isn't staying in one column, not even close. Just reving it in neutral I'm hitting ~80%, but under 5psia of boost at redline it seems as though I'm climbing BACK to 40-60% load. So there's more load when I've reving it in neutral than at 5psi redline? Comming from speed/density this doesn't make any since, but I'm guessing that it's a function of airflow vs engine speed or something? But even then I don't see how airflow/rpm from no boost could match or exceed that of boost?
So then what exactly is defined as 100%?, and what happens if I exceed that? I mean if this was designed as an NA ecu, than 100% I would think would be a little above that as defined as max airflow at sea level with ambient pressure? I'm sure the ability to log correctly, or maybe even manipulate the MAF trans would make this so much easier to tune. But I'm past the point of it being hard, now I'm just trying to understand how/why it works and how that load number is derived? I mean 100% is great, but 100% of what?
I mean if it was based off throttle 0 = closed, 100 = open. MAF flow 0 = 0, 100 = (you'd have to know the peak i guess). But this number seems to be going down as the flow increases.
Now Honda is SD, easy. Ford, Sub, and some chevy seem to use a defined load of g/cyl or g/sec, or g/cyl/sec or some DEFINED variation there of. Some chevy does use a LV8 term, which I still don't understand either, but it at least seems to be a little more predictable and constant than on here.
Any help or thoughts would be great, I'm just trying to understand the thinking behind all this.
UPP