12 LFX vs 13/14 Cam VVT positioning... Why so different?

[Jason@JacFab]

Playing with HP Tuners recently and thought it would be interesting to compare the differences in the tunes from year to year... For the most part most of the stuff is just small tweaks here and there, but what appears the biggest change between 12 and 13/14 (13 and 14 are nearly identical) is the difference in the tables for the cam positions...

I've attached a picture of the WOT cam positions for both the 2012, and 2014 side by side...

The non-WOT tables are quite a bit different also, about 6 degrees max in some areas, but the WOT tables look pretty drastic to me. I can't seem to find a multiplier, or modifier that would magically bump the 2014 table up to around where the 12 is... Very strange.

Anyone have any insight on this?

[JantzenOKC]

I have exactly 0 insight on this but I do remember reading that 12's had a different ecm than the 13 and 14's

[Jason@JacFab]

Originally Posted by JantzenOKC

I have exactly 0 insight on this but I do remember reading that 12's had a different ecm than the 13 and 14's

You are correct there, the 12 has an E39, where as the 13 and 14 have the E39A... Not really sure how much different it is?

I can honestly say, you don't want to try to run the 2012 cam timing tables in a 2014... I copied them into my stock 2014 tune along with the VCP spark, and it turned it into a TOTAL DOG, absolutely horrible... Looked like it might be good on paper, but not so much.

Operation

The CMP actuator assembly has an outer housing that is driven by an engine timing chain. Inside the assembly is a rotor with fixed vanes that is attached to the camshaft. Oil pressure that is applied to the fixed vanes will rotate a specific camshaft in relationship to the crankshaft. The movement of the intake camshafts will advance the intake valve timing. The movement of the exhaust camshafts will retard the exhaust valve timing. When oil pressure is applied to the return side of the vanes, the camshafts will return to 0 crankshaft degrees, or top dead center (TDC). The CMP actuator solenoid valve directs the oil flow that controls the camshaft movement. The ECM commands the CMP solenoid to move the solenoid plunger and spool valve until oil flows from the advance passage (11). Oil flowing thru the CMP actuator assembly from the CMP solenoid advance passage applies pressure to the advance side of the vanes in the CMP actuator assembly. When the camshaft position is retarded, the CMP actuator solenoid valve directs oil to flow into the CMP actuator assembly from the retard passage (3). The ECM can also command the CMP actuator solenoid valve to stop oil flow from both passages in order to hold the current camshaft position.]

ALLDATA Info from a 2013.

[ChibiBlackSheep]

Are these all from the same model/trim?

For example are they all 1LS models, or all 2LS models? Do you know?

I wonder if your 2012 is actually a 2LS and the rest aren't, and the small change can help EPA or something

[Jason@JacFab]

Both the 2012 and my 2014 file appear to be Automatic, 1LT trim cars.

The 2013 file I have appears to be a 2LS, but the cam timing on the 13 vs 14 @ WOT is exactly the same, the part throttle tables, and 99% the same.

I wonder if the AllData info I highlighted in red works the opposite way in the 2012/e39, ie the Intake cam starts fully advanced, and gets retarted as the numbers climb in the tables, VS maybe starting fully retarded in the 14/e39a and get advanced, which is why the numbers from the 12 don't work in a 14?

I have no clue. But I'd like to learn.

[IneedAZ]

Originally Posted by Jason@JacFab

Playing with HP Tuners recently and thought it would be interesting to compare the differences in the tunes from year to year... For the most part most of the stuff is just small tweaks here and there, but what appears the biggest change between 12 and 13/14 (13 and 14 are nearly identical) is the difference in the tables for the cam positions...

I've attached a picture of the WOT cam positions for both the 2012, and 2014 side by side...

The non-WOT tables are quite a bit different also, about 6 degrees max in some areas, but the WOT tables look pretty drastic to me. I can't seem to find a multiplier, or modifier that would magically bump the 2014 table up to around where the 12 is... Very strange.

Anyone have any insight on this?

Jason, what tab are these tables listed under?

[Jason@JacFab]

ENGINE > AIRFLOW > VARIABLE CAM SHAFT

The tables shown are the WOT, there is also a bigger table for part throttle driving for LOW/MED/HIGH which is based on barometric pressure.

[IneedAZ]

thanks

[norris_83]

No matter what values are set at, there is always more power to be had with playing with these tables.

GM retards and advances their cam profiling for mileage. I've gained at least 15whp from tuning these tables alone on a bolt on car.

[IneedAZ]

Originally Posted by norris_83

No matter what values are set at, there is always more power to be had with playing with these tables.

GM retards and advances their cam profiling for mileage. I've gained at least 15whp from tuning these tables alone on a bolt on car.

Did you find you increased or decreased or both the factory numbers

[norris_83]

Originally Posted by IneedAZ

Did you find you increased or decreased or both the factory numbers

all depends on what mods you have on your vehicle. To pin point whats best, you'll need a dyno. On a C7 decreasing the values at higher rpms gained us power.

On a Gen5 pick up with a VVT cam, increasing the values actually increased around 28wtq!

https://instagram.com/p/8G-pTem8nd/?taken-by=mep_q8

[qcman]

I know nothing about tuning but I was thinking this could have been changed to correct some of the many v6 misfire issues I've read about on here?

[IneedAZ]

So, anybody mod these on a v6?

[MagnumForceGB]

Yes, it's one of the things I used to shave 0.7 seconds off my ET. They are used to broaden the powerband.