I love subtle hints
I love subtle hints
Can someone in laymens term explain this to me. Ive read it a few times but dont quite understand what its significance is sorry I am having a blonde moment. LOLOriginally Posted by SS2win
EFILive - The Single version of the Truth
Larry - HumpinSS
Whoa, hang on guys, you need to consult with me first
Just kidding, it's funny as we go through this GM code how the LS1 actually missed out on some neat stuff. The Duramax (and as Paul said LS2) have alot of tables where you can define the axis breakpoints.
So as an example, instead of 400, 800, 1200, 1600, 2000 RPM, you can change it to 400, 600, 800, 1000, 1200 etc. It's a coding nightmare, so lets not go there
I like these custom O.S ideas, it's just time is the enemy, I was hoping that a few of the V4 O.S would be out by now, but with LLY Diesel about to be released in a few weeks it has been held up.
Plus a few of you seem to be having some drama's with the latest V3 O.S changes causing super rich running?, not sure what is happening there.
My opinion on high res VE tables, not worth it, 10kPa is plenty, anyone ever looked at FORD tables
Cheers,
Ross
I no longer monitor the forum, please either post your question or create a support ticket.
Hmmmmm....
wait4me - can you further explain or clarify this?? Why won't it then fight at higher resolution...of course smaller ripples.
Cheers,
joel
****ALL OF THESE EMOTICONS - and not a "Cheers"???************
ok, you have 400 rpm at a cell, 400 rpms a lot can change with a higher hp car.
Currently, when the vehicle is being autotuned, the vehicle may only need 2% correction at 200 of the rpm, and 5% at the 400rpm but the blending would say that the cell is 3% off. but depending on the other surrounding cells, since every cell touching the cell in question, They all Start to OVER correct or UNDER correct the cells. But, with higher rpm resolution, it would be able to see those types of fueling needs and would make a less mountain range type of ve table. When you see a spike, that means the the surrounding cells around it are all off, and so is the spiked cell too.
I get it! Thanks
Cheers,
joel
Jesse,
Not to start one of those silly arguing games most foums suffer from, but I must disagree on this one.
When you tune an engine on a dyno (in steady state) you will rarely see dramatic differences in VE with 400 RPM increments. Air pumps just don't work.
Now, granted there might be one small section of RPM where the VE changes quickly due to several factors like camshaft, compression ratios, etc.. but overall it is rare to see an engine need such high resolution across the board.
In fact 9 out of 10 engines rarely need more than 1000 rpm breakpoints to achieve flat AFR's. Most will need finer resolution in one small section, but almost none will need it everywhere.
Part of the problem stems from doing Auto VE stuff on the street where the cell sampling can be hit or miss, unlike holding the engine steady on a dyno in the center of each cell. This tends to "smooth out" the table and eliminate the problems you have keenly observed of certain cells becomming blended or averaged to get an overall AFR quality without any one cell being exactly correct.
Having a higher resolution table will only magnify the problem using non-steady state tuning methods, and would yield almost exactly similar results by the hold and tune method, but with much greater time required to reach the same goals. What you would end up with is a whole lot of cells containing the same or very similar values.
As far as the MAP values needing higher resolution, the need doesn't really exist there either. Simple laws of physics dictate a relatively easily calculated rate of change in mass for a given rise or fall in MAP. Thus, if you have a value at 175 kpa, and another cell needed to be filled in at 200 Kpa, it is easy to out the correct number in the table to acheive the same AFR or any other AFR for that matter.
Let me try to simplify this all:
Each engine will be different and will tend to need higher resolution in one area or another, but rarely is the error so large that minsicule break points are needed across the board.
Proper steady state tuning on a load bearing dyno will yeild the results you are looking for without the need for our friends Paul and Ross to re-invent the wheel.
Try this for an experiement:
Tune an N/A engine on a dyno at WOT and (hopefully) 100 KPA to have the same AFR across the entire RPM range. (doesn't matter what AFR, so long as its all the same)
What you will notice is that the changes is the table values should reflect the same shape as the engine's torque curve.
Is the engine's torque curve jagged and mountainous? If not, then the table shouldn't be either.
Where ever there are peak's and valley's in the torque curve, there should also be the same in the numbers in the table.
If there are spots in the table where the correct AFR can't be reached because it is between two RPM breakpoints, then you could say with confidence that more resolution is needed in that area.
I think what you will find is that the stock PCM tables already have all the resolution you need for the majority of enignes.
I hope you won't take any of this offensively, as it was certainly not meant to be. I hate those kind of forums.
If what I said helps, then great...if not toss it out and forget I mentioned it!
Yes, but there is a pole dancer:
Jesse , you can already do it by tricking the map scaler , you can have a table with 3 times the resolution in 1 bar mode if you desire
Ben, I don’t think there would be anyone that would take offence to these comments and opinions.I hope you won't take any of this offensively, as it was certainly not meant to be. I hate those kind of forums.
If what I said helps, then great...if not toss it out and forget I mentioned it!
We appreciate you’re input.
Cheers Scotty.
It's a lot easier to ask for forgiveness than it is to ask for permission.
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