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Hey Guys,
Trying to grasp the concept of the virtual VE table in the gen 4 ECUs. If it's not a real table in the tune what exactly are you tuning and how is the ECU processing MAP sensor input to do fueling? To follow up is it a functional VE replacement where you can delete the MAF sensor?
Working with a 2010 Camaro.
Thanks
Malcolm
I'm not exactly as experienced as most on here but here is my take on it. I have a 15 Camaro so it's the same. There isn't a normal VE table like the gen 3s. It is all coefficient based as seen in the tables on the airflow-speed density tabs. You use the VVE table similar to how you would on a gen3 VE table. Except it isn't as precise because it is divided into zones. Go into the VVE table and click show zone numbers to see the different areas. Anyway, you make your changes using the VVE table as you would a regular VE table. After making your changes, you click calculate coefficients to convert the traditional style VE changes you put on the VVE table into all the coefficient changes in the tables in the SD tab. It is a tool to more easily change all the formulas as required to run correctly. I wouldn't necessarily delete the MAF as they "check" each other when in blended mode. Actually, I think my MAF was faulted when it threw an airflow correlation code, can't remember. Either way, I would rather dial both MAF and VVE in to have the best of both. Anyone correct me if I have any issues here, but I hope this will help.
That sounds along the lines of what I've been reading. Apparently the virtual VE table came about due to variable cams, DOD and possibly other things making the complexities of an actual VE table(s) not practical. So instead it's calculated from various coefficients in the tune.
I'm still trying to find out how well these newer ECUs run without a MAF in only VE mode. This 2010 car has a turbo installed and the MAF was deleted. Trying to decide if I should have the guy weld in a bung and re-install the MAF or just VVE tune it only.
They run decent without the MAF if you have a 2 BAR speed density OS upgrade. They do not run that well if you are only use speed density off the factory OS.
If you have the factory OS, I'd suggest installing the MAF again. Run a card style MAF and put it in a 4in or 4.5in tube so you don't outflow it and install a honey comb air straighter to keep a nice laminar flow across the sensor.
That's good to hear it could run well on the MAP sensor only. I could always get the 2 bar sensor and do the OS upgrade. Is there a specific 2 bar sensor I should get?Quote:
Originally Posted by 5FDP
The turbo kit is already built so the MAF could go into there if they did that. I'd have to see what diameter piping that is. I have a feeling it's closer to 3" but I'll have to take another look.
Agreed on a screen to straighten out the air. Otherwise you get so much turbulence normally in my logs I see the MAF voltage bouncing around even under boost from the turbulence. A screen does wonders for the MAF signal.
I wouldn't say that. I was forced to do one here recently on an early e38 with vve only. Did just fine once you get it all dialed in. Very time consuming honestly.Quote:
Originally Posted by 5FDP
If you had tons of time I'm sure getting everything really close and dialed will make it operate good. A dyno likely makes it far easier than doing it on the streets. I'm not sure I could maintain all the speeds or loads trying to do it on the road.
So in reading in the tune I noticed this one has 3 sections to it. On the Gen 3 ECUs I've been messing with I don't recall seeing this. Looks like engine, trans, and something else. I think fuel system on the third? The third one throws an error reading in. Is that a problem?
https://lh3.googleusercontent.com/mE...M=w836-h672-no
Here's the error
https://lh3.googleusercontent.com/UI...I=w408-h370-no
Should be the fuel pump control module. I couldn't read mine without a similar error. Just skipped the read on it. Good to know I wasn't way off track on that VVE stuff :cool:
Good deal. Decided to get the MAF installed since HPT seems to only have an OS upgrade for a 2 bar MAP sensor and this car will see more than 14 PSI of boost. So we'll use the MAF.
The 2 bar OS can actually do 2.5 bar if you edit the VE tables manually. That's roughly 21psi.
If you were to upgrade the OS and you clicked on your new VE tables, open the table, then click the MAP axis at the top. Click the last cell on the right and the largest number you can type in there is 255kpa. You can then interpolate downwards towards your starting 15kpa.
That's good to know. So what physical sensor do you buy? because 2 bar is technically 1 bar above atmospheric pressure right? so that would be 14.7 PSI as a limit of the MAP sensor itself.Quote:
Originally Posted by 5FDP
A 3 bar sensor from a CTSV or Camaro/Corvette. They run the same sensor and the data is plug and play.
Ah great. Thank you.