2008 VMax - looking for input tune enclosed

[J-Rod]

Just wanted to share my current tune and give an overview of what all I have done. Feel free to ask questions, give advice, or provide criticism.

The truck is 100% stock. So, no modifications to the exhaust, air intake, etc...

Tune #1 is the intial read. Tune #2 is the current tune. The tune was done in the current Beta to access the VCT parameters.

In the intial tune, there was as much as 20 - 30 degrees of retard in the lower RPM ranges. I suspect much of this was to assist with torque mgmt. I have now zeroed out the ranges below 2400 RPM. My hope is to get the truck on a load dyno and play with retarding the camshaft at High RPM to boost power. The truck also has an initial base value on the cam. I would like to see if this could be set advanced intiall so that the cam would be advanced to start with, and then retard the cam as you get into higher rpm.

I have modified the PE delay by changing PE delay RPM to 0, and the PE rate from .2 to 2.00.

The PE TPS threshold is slightly different.

The PE multiplier is probably a bit differnet than many folks are used to. I need to get a WB on the truck to verify it currently. But I will outline what I am trying to do. The truck makes peak torque around 4500. I normally see folks run the same A/F across the board (ie 12.8 - 13.0). However, I disagree with this. An engine needs more fuel at peak torque. so, I've set my PE to be around 12.5 at peak torque and rolling off to 13.0 at peak HP.

DoD is something I've been playing with quite a bit. Most of the tuning I've done is in 4th gear crusing on the freeway. I have played extensively with the DoD tables as far as timing, and also withte enable and disable vaccum. I had set disable to 0 for awhile which forced you to use throttle to get out of DoD. But that was a bit harsh. You can tun DoD on the Vmax down to 1 or 2 comfortably.

Spark advance was limited to copying the hi octance table to the lo octane table. I plan on upping the hi octane table a bit in certain areas to wake the truck up. I also need to go back and do some new logs to verify the truck is seeing no KR. After the copying the hi octane table I've run nothing but 87 octance, and in all the logs I've seen no KR. However, its very hot out, and I've recently changed the multipliers for IAT and ECT. I want to see if those changes have had any effect in KR. Again, the hope is to ge teh truck on a load dyno and see what we can do to tune for best power and torque on low grade fuel. I've also reduced the knock retard fast attack rate.

For torque management I really have done very little. I wil admit I am hesitant to reduce a lot on a big heavy truck. I would prefer to keep the truck from dumping its guts on the ground. I may do a Corvette servo and shift kit at some point. But for the time being I have left all the torque managment values as is. If someone disagrees with this, feel free to share your insight on what you'd moidfy those values to. The only thing I have done for Torque mgmt is Using the beta, I disabled the tip in ETC limit.

Last thing in the tune was to disable the speed limiter.

So, anyway, feel free to comment... the tune still has a long way to go. But its a good starting point.

[J-Rod]

Well, I kinda suprised not to see anything thus far from anyone... I thought maybe the VCT stuff might spark some discussion. But, I guess not...

[coryfountain]

J- Rod.... what transmission to you have 6l80e? or 4l80e?

[J-Rod]

4L70E. I'm actually considering getting rid of the truck to switch to an '09 or '10 to get the 6.2L 6L80E/6L90E.

[coryfountain]

From what i understand is that the 6.2 wont tow as much as your vmax... but i can tell you this... My 6.2 will run circles around a 6.0... Once she hits about 6k miles she wakes up.... plus the Tuning of course!

[ccspiringer]

I have a 08 Sierra 6.0 Vmax. I was hoping to look at the tunes you posted, but nothing was there. I have just started tuning my truck and was hoping to get some examples to look at. You still have those tunes?