GM 3.6 VVT Parameters.

[zmooney2011]

3.6 DOHC VVT. Does anyone know what the cam angle parameters in the stock base cam angle table represent, because they are all over the place. For instance intake cam shows anywhere from pos 7 to neg 41 deg. My confusion is that per GM service information intake can only be advanced, 0-25 crank deg. and exhaust can only be retarded, 0-25 crank deg. Stock tables do not correlate to degrees of command. So what do they refer to?

Not finding much on DOHC tuning. Only Single cam VVT.

[chrispana454]

Hey mate i believe with the 3.6 litre hfv6s they have 50 degrees of advance authority . Mine is a 175 kw dohc (intake only variable) and has similar various cam positions as youve described. Cheers Chris

[zmooney2011]

Thanks for the input, i was thinking only to 25 cause that?s all you can command it. But I think your right on that my tables go pos 7 to -41 so yeah about 50, but if it was referring to degrees of command I wouldn?t think there would be negitive and positive on the same table when the cam cam only move one way from parked. I think it is referring to before top dead center on the intake side pos 7 being 7* BTDC and say -10 being 10 deg after TDC on intake stroke to hold the valve open later and reduce cylinder pressure for mileage and that. Just a theory. I?ll have to play with it and see what happens.

[MagnumForceGB]

For the E69 ECU (LLT, LY7):

In the tune itself, when the Intake Valve opens is what the numbers mean in its table (7 degrees is 7 ATDC). In the exhaust table it is when the exhaust valve closes (15 degrees is 15 ATDC). The intake valve can only advance so it can go to -43, the exhaust can only retard so it can go to 65.

In the scanner, it goes by how many degrees it is moving the cams, so 0-50 degrees.

For the E39 (LFX):
The table reads in camshaft position, so 5 degrees is 10 crank degrees advance. It is more traditional then how the LLT is.

[zmooney2011]

Thank you for clearing that up. That makes sense.