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View Full Version : Varable Valve timing for L92 6.2L


02Z06
June 21st, 2007, 06:17 PM
Are these tables going to be implemented for the 6.2L Cad. Escolade?
RonC
June 22nd, 2007, 01:34 PM
I would also like to know about VVT tuning for the 6.2L.
GMPX
June 23rd, 2007, 12:59 PM
We can add these in for sure, but depending on how complex it all works we might not get around to it for the next release which will be the E67 .cals this week sometime.

Cheers,
Ross
minytrker
June 24th, 2007, 02:35 AM
What about being able to just turn off VVT? I want to put a 6.2 in a trailblazer and just turn off the VVT.
ScarabEpic22
June 25th, 2007, 11:13 AM
Why turn off VVT? It makes waay more power with VVT, look at the 4.2L I6 LL8 with VVT. It makes almost as much hp as the 5.3L V8s do (yes less TQ, but its an inline engine too).
XLR8NSS
June 26th, 2007, 10:09 AM
What parameters does the VVT use to determine the camshaft position? I'm just wondering how it would be on a Forced Induction setup. Seems like advancing the cam down low with a fast spooling FI setup might not be good, the cam retard in the upper rpms might work out decent though.

If there is a load parameter it's based on in there somewhere that might be alright though. :)
GMPX
June 27th, 2007, 01:03 PM
I've added some VVT tables in to our next round of Beta calibrations.
So they will be appearing in the near future for you guys too.
I agree with ScarabEpic22, leave the feature on, seems like a good thing to me.

The desired position is based on Air Flow (load) and RPM.

Cheers,
Ross
XLR8NSS
June 27th, 2007, 01:14 PM
Looks like that will work out nicely with a FI setup. :)

That attachment makes me curious now though. I see a table in there for "Cam position in AFM mode". I didn't realize there were any vehicles yet with both features or is that a glimpse into our future. :)

Thanks Ross.
RonC
June 27th, 2007, 02:44 PM
Looks like that will work out nicely with a FI setup. :)

That attachment makes me curious now though. I see a table in there for "Cam position in AFM mode". I didn't realize there were any vehicles yet with both features or is that a glimpse into our future. :)

6.0L in the new trucks comes with both AFM and VVT.

Is this a screen shot from a 6.0L or 6.2L and if so, within the VVT adjustment range of 0 to 30 degrees, what number would represent a regular cam installed straight up, "0 degrees advanced"?

Ron
GMPX
June 27th, 2007, 03:41 PM
6.0L in the new trucks comes with both AFM and VVT.

Is this a screen shot from a 6.0L or 6.2L and if so, within the VVT adjustment range of 0 to 30 degrees, what number would represent a regular cam installed straight up, "0 degrees advanced"?

Ron

It's from a 6.2L Escalde.
The degrees would represent angle from the mechanical rest position, so if the cam was installed advanced then the table values would represent the timing from that advanced position. I have not found (if there is any) a parameter specifying electronically a reference angle the cam is installed at.

The thing to remember about these ECM's is they are used on a wide range of engines now, so even though some engines don't have certain 'mechanical' functions it will still be shown in the tuning tool.

Cheers,
Ross
XLR8NSS
June 28th, 2007, 05:41 AM
6.0L in the new trucks comes with both AFM and VVT.

Is this a screen shot from a 6.0L or 6.2L and if so, within the VVT adjustment range of 0 to 30 degrees, what number would represent a regular cam installed straight up, "0 degrees advanced"?

Ron

That must be a relatively new deal. I just noticed that the Vortec Max 6.0L has VVT and AFM now. I don't remember it having both when they first came out.
RonC
June 28th, 2007, 10:54 AM
That must be a relatively new deal. I just noticed that the Vortec Max 6.0L has VVT and AFM now. I don't remember it having both when they first came out.

They did and the 6.2L in the first Escalades had both but had AFM disabled, and some early 6.2 crate motors had it installed. I read somewhere that they had some problems getting it to work satisfactory with the 6 speed auto. Maybe, maybe not. I don't think the later production 6.2L has it installed. Maybe in 2008. I'm looking forward to playing with VVT when tuning beomes available. Tuning really made a big difference in the way the 6.2L runs, but on a WOT shift, the trans TR still pulls delivered torque down from 400 ft lb to 60 ft lb making a real unimpressive shift. Oh well, its temporary.