DFM disabler released

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Marky Dissod

Full Access Member
Joined
Mar 3, 2023
Posts
2,032
Reaction score
2,829
Location
(718)-
DFCO does NOT deactivate cylinders - or if you prefer, DFCO does not deactivate valves.
During DFCO (and powertrain braking), valves open and close normally,
like it's been done since the 50s, or whatevar.
It's merely FUEL that is not being used during DFCO.

I suppose DFCO could be combined with cylinder deactivation,
but wouldn't that be past the point of diminishing returns?
If you're already not injecting any fuel into any cylinders (DFCO),
you're already using zero fuel.
What additional benefit would there be to also deactivating the valves while ALREADY using zero fuel?
 

KMeloney

Full Access Member
Joined
May 2, 2009
Posts
2,918
Reaction score
335
DFCO does NOT deactivate cylinders - or if you prefer, DFCO does not deactivate valves.
During DFCO (and powertrain braking), valves open and close normally,
like it's been done since the 50s, or whatevar.
It's merely FUEL that is not being used during DFCO.

I suppose DFCO could be combined with cylinder deactivation,
but wouldn't that be past the point of diminishing returns?
If you're already not injecting any fuel into any cylinders (DFCO),
you're already using zero fuel.
What additional benefit would there be to also deactivating the valves while ALREADY using zero fuel?
Just wanted to say that I learn a lot from your posts with your technical insight. Keep it up, please!
 

Marky Dissod

Full Access Member
Joined
Mar 3, 2023
Posts
2,032
Reaction score
2,829
Location
(718)-
Just wanted to say that I learn a lot from your posts with your technical insight. Keep it up, please!
You'd be shocked at how much you learn from
tuning mid-90s LT1s
asking every question your tuner'll allow when he's tuning your GMT932.
Many of you who think you're against engine / transmission tuning,
would be for it if you understood what they're capable of.

(An answer to a question no one asked: my stance on cylinder (valve) deactivation has nuanced.
I'm still against it ... UNDER 221F {that's a coolant temp threshold}.
Me AND my 2013 YXL tuner know from experience that too much V4 mode increases oil consumption.
Cylinders that get even a wee lil bit too cold from taking too long a break increase oil consumption.
But that same cylinder deactivation can be used to delay or mitigate overheating.

So, instead of disabling cylinder deactivation, just raise the enable temp to 221F,
or 230F if you're braver than I am.)
 

KMeloney

Full Access Member
Joined
May 2, 2009
Posts
2,918
Reaction score
335
my stance on cylinder (valve) deactivation has nuanced.
In light of the fact (I think) that I won't get this truck tuned (got my '01 Z06 tuned, but not this truck), do you recommend the Range disabler? And do you have an opinion on the Range unit vs the Carbyte unit?

Thanks!
 
Last edited:

Scarey

Member
Joined
Oct 15, 2024
Posts
47
Reaction score
20
That’s what I’m trying to figure out. 2024 tahoe 6.2. I have the range 007 and have been playing with it. It’s not much trouble to install, floor jack a few inch’s and slide on your back from the nose and simply pry back the wheel well carpet and you can plug and unplug. So that’s not a big deal. Yes the obd port would be easier. Driving in L9 or driving with range appear to be identical. Both appear to be identicle in coasting, foot of the gas. Both show 99 on the instant mileage page. Both feel identical, sound identical, shift identical. This is why I’ve been asking so many question's about 0 cylinder mode coasting. People claim l9 completely disables Dfm. Coasting with range 007 feels like l9. So does that mean range does completely disable Dfm? If coasting truly is just starving the cylinder of fuel and not deactivating the valves with Dfm then range is what I’m looking for. If coasting is using Dfm then I’m not satisfied with range solution. Im not sure yet. I ordered a carbyte and will play with it. My curiosity has the better of me.
 

Marky Dissod

Full Access Member
Joined
Mar 3, 2023
Posts
2,032
Reaction score
2,829
Location
(718)-
In light of the fact that (I think) that I won't get this truck tuned (got my '01 Z06 tuned, but not this truck),
do you recommend the Range disabler?
And do you have an opinion on the Range unit vs the Carbyte unit?
1stly, I recommend getting tuned.
However, I know that is getting not only more expensive, but logistically more difficult.
Pretty soon, even when you buy something brand new, it won't really be yours, which pisses me off.

2ndly, I recommend disabling cylinder (valve, really) deactivation generally.
Our engines would tend to last 200,000 miles or more given regular maintenance by any schmuckdiot.
Cylinder-valve deactivation has made 200,000 miles much more difficult and costly for the owner operator,
and only encourages further complexities by carmakers which will drive up future owner operator costs.

You gotta decide which fulltime V8 device suits your needs and wants,
but I like the ones that plug in under the dash, because I can remove or plug it in in two seconds.
 

KMeloney

Full Access Member
Joined
May 2, 2009
Posts
2,918
Reaction score
335
That’s what I’m trying to figure out. 2024 tahoe 6.2. I have the range 007 and have been playing with it. It’s not much trouble to install, floor jack a few inch’s and slide on your back from the nose and simply pry back the wheel well carpet and you can plug and unplug. So that’s not a big deal. Yes the obd port would be easier. Driving in L9 or driving with range appear to be identical. Both appear to be identicle in coasting, foot of the gas. Both show 99 on the instant mileage page. Both feel identical, sound identical, shift identical. This is why I’ve been asking so many question's about 0 cylinder mode coasting. People claim l9 completely disables Dfm. Coasting with range 007 feels like l9. So does that mean range does completely disable Dfm? If coasting truly is just starving the cylinder of fuel and not deactivating the valves with Dfm then range is what I’m looking for. If coasting is using Dfm then I’m not satisfied with range solution. Im not sure yet. I ordered a carbyte and will play with it. My curiosity has the better of me.
Please let us know how the Carbyte compares to the Range, since you'll be able to do a direct comparison of your own. Very interested to hear your take on the two.
 

KMeloney

Full Access Member
Joined
May 2, 2009
Posts
2,918
Reaction score
335
You gotta decide which fulltime V8 device suits your needs and wants,
but I like the ones that plug in under the dash, because I can remove or plug it in in two seconds.
Thanks. And given that I've got a '23 Denali with the 6.2, I'm a potential candidate for the engine seizing. And whereas I'm hoping I never have that situation occur, I wouldn't want someone to try to say that having the Range installed contributed to the failure.
 

Forum statistics

Threads
132,784
Posts
1,874,232
Members
97,627
Latest member
Yit434
Top