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View Full Version : Can EFI Live be used to tune VVE with a L92 VVT engine??



CI GEARHEAD
November 22nd, 2010, 06:03 PM
Hi. I'm not a tuner, but I have a friend who is very proficient with tuning the LS1 motors with EFI Live and he and I have been tuning on my '08 Sierra Denali for over a year with it. We have read Swingtan's tutorial and want to dial in the VVE, as we can't get the AFR any higher than 12.0 to 12.4, even if you command a 12.8 in PE.

However, I have read the warning pop-up when you open the VVE tables in the tune tool that says:

"Variable camshaft positioning is not currently supported in this version. DO NOT use this software version to tune controllers/engines that implement variable camshaft positioning."

Does this mean that we shouldn't be using EFI Live to tune my truck? If not, what version should we use? My truck has the L92 w. VVT (I have in fact changed the cam to a Mast Motorsports VVT "Truck" cam)

I mean, we have been using this to tune my truck for over a year, to retune when I changed the cam, converter, gears etc, and have even tweaked the cam phaser a whole bunch, so what the hell does this mean??

The truck runs good, just a bit rich @WOT and we want to try to tune the VVE, but now I'm worried.:help2:
Here's a log that we have made recently, after I changed the gears to 4.10s:
Any guidance input would be appreciated.

swingtan
November 22nd, 2010, 07:29 PM
Hi Gearhead,
I believe the issue is not that you can't tune the ECM, but that the VVT components will introduce unknown variables to the tuning process. I don;t think there is a "cam position PID" in scantool, so it's difficult to know exactly what is going on. You could try working around the lack of PID buy...


Disabling VVT in the tune.
Dial in the VVE with no VVT active.
Re-Enable the VVT and then use the VVT tables to "correct" the airflow mismatch.


I'd look into it a bit more, but have just had my Windows profile corrupted and started from scratch, so none of my EFILive settings are done yet.

Simon

CI GEARHEAD
November 23rd, 2010, 01:56 AM
Thank very much Swingtan. That makes sense to me. I am going to look for the cam position PID too. I vaguely recall my friend talking about us needing to log or logging cam position, but I don't know if we ever did. I only have some of the logs on my laptop and he has the majority on his. I will ask him and revert with what he says. He is a pretty competent guy and has been telling me we need to use your tutorial to tune the VVE from a year ago, but we've just never got the time to do it.
It seems that most, if not all, tuners (at least in the US) just leave the phaser curve alone, which a lot of guys with aftermarket VVT cams are complaining about now.
I would like to get this sorted, because I beleive that there some HP left on the table and folks won't start to understand the real benefits of VVT until we can really tune the phaser and log cam position to see what the cam is actually doing. A lot of people shy away from and delete the VVT because they don't trust the hydraulic phaser actuator.

CI GEARHEAD
November 23rd, 2010, 02:21 AM
Just checked the list of PIDs (F8) and found in the list (although not selected):

"Intake Cam Phase Actual Angle Bank 1 - INPHAB1" and "Intake Cam Phase Actual Angle Bank 2 - INPHAB2", and a bunch of other related PIDs.

Would this be a PID I could use? It's obviously tailored for overhead cam V- engines, but I'm assuming that if I knew what angle to look for on one of these, I could use it to log cam position? In the tune tool, we have always tuned the Intake Cam (High Baro - since we are at sea level) position when we were working on the cam phaser curve, so I'm thinking its only logical to log intake cam position??

CI GEARHEAD
November 23rd, 2010, 02:31 AM
Just also found in the list of PIDs:
"Cam Phase Angle Actual - CAMPA"; "Cam Phase Angle Desired - CAMPA_DES" "Cam Phase Angle Variance - CAMPA_VAR" and "Camshaft Position Retard (Vortec) - CMPRET".
I beleive the "Cam Phase Angle Actual" is probably what I need to log? And if I also log the "Desired", one, that would tell me if the VVT is doing what it's supposed to do, I think.