Questions for those that increased 4V time

[robgreg75]

I have read about people remapping the engine software to keep the engine in 4V mode longer such as uping the throttle opening percentage.

For those that have I am curious:

1. What kind of mileage improvemants have you seen
2. How rough is the engine in 4V mode at the higher throttle
3. How is the transition from 4V mode to 8V mode at the higher throttle

My guess is the latter 2 questions may be why GM limited the cutoff to only 6% throttle.

Thank you,

Rob

 

[White07Tahoe]

I got the in person blackbear tune with jason and I had him increase the V4 mode and I do not regret it at all. There was a definite power and MPG increase from the tune. Engine does not run run rough. Transition is the same as stock, barley noticeable. I suggest doing it.

 

[iwaslowr]

I too have the BB tune and love it... Even Justin himself was surprised at my Yukon lightly accelerating, and later also going up a slight hill, in V4 mode!! I haven't measured mileage though. My experience is that the V4 mode has a distinctly, yet understandable, more aggressive rumble than V8 mode (I actually enjoy the sound!)... and the behavior when transitioning between the two modes does not seem any different than the stock tune.

 

[robgreg75]

Thanks for the replies. I was thinking of buy a HPTuner and do myself but if the V4 mode was rough and transitions hard was not going to try.

 

[cjg454ss]

i did mine with hptuners, its very easy. compared to performance tunes or drag cars...AFM tuning on a suv is simple. actually the extent of tuning any of these SUV's requires a level 1 tuner at best. shift points/ tq management...all monkey level tuning

 

[04ctd]

since it's been two years on this post, how has it worked out?

has extended AFM tore up the motor, or not?

see this thread:
http://tahoeyukonforum.com/forum/showthread.php?t=50089&highlight=afm+tear+up+engine

 

[Zed 71]

No issues here.

 

[Kenric]

Has anyone compared their fuel economy stock vs. more aggressive V4?

I've seen lot of talk about the transition, sound, and durability but nobody has put a number to the fuel econ improvement, which is the whole reason one would want to spend more time in V4 mode.

 

[JennaBear]

On the 6.2Ls there is better fuel econ, not so much on the 5.3Ls.

 

[soulsea]

I had Justin actually remove V4 mode altogether in my (Denali) tune. But that's because my primary aim was neither increased power nor improved fuel efficiency, but rather to remedy the infuriating bogging down on low gear upshifts and general transmission shortcomings. Many elements of the tune were adjusted to this end, including deactivating AFM. It worked.

 

[ToddEdge]

What exactly is 4V mode?

Thanks,
Todd

 

[soulsea]

Fuel management ... engine switching to 4cyl mode to save fuel.

 

[04ctd]

my 2007 got 22mpg over 4 tankfuls from SC to NY (2 tanks up, 2 back)

must have been a flat area around PA or something

around town, i get ~17mpg.

but if you consider that you really only get that GREAT mpg on long trips, and AFM is caking up the carbon in the cylinders that are not running,
that bit of increase is not worth it.

Texas SPeed and other shops make kits to take out the AFM/DOD lifter and replace them with regular parts.


AFM/DOD Delete Kit

All the parts you need to remove the Active Fuel Management System from your AFM vehicle.

DOD Delete Kit, Includes: LS2 Chain Dampener, LS7 Lifters, LS2 Lifter Trays, LS3 Head Gaskets, Your Choice of Head Bolts, LS3 Valley Cover, PCV Hose, PCV Plug, Cam Swap Gasket Kit.


base price $389.99

 

[jetmech]

i did mine with hptuners, its very easy. compared to performance tunes or drag cars...AFM tuning on a suv is simple. actually the extent of tuning any of these SUV's requires a level 1 tuner at best. shift points/ tq management...all monkey level tuning

can you send me some screen shots of which tables to modify ?