What is de-fueling? Is this related to the amount of boost? Can I modify it/them and if so, how?
What are the pros and cons?

 

2 types of defueling.

There is the high rpm defuel that starts around 2700. Thats when the ECM starts to cut back fuel.

Then there is the torque managment that happens with the 01 and up auto trucks. It was DC's way of trying to save the auto at low rpm when the truck wants to lug.

 

[quote author=figure_9_pro link=board=4;threadid=20840;start=0#msg195554 date=1065842270]
What is de-fueling? Is this related to the amount of boost? [/quote]

de-fueling is just that. DE-Fueling. As you may know, Diesels have no set air ratio to maintain, and no throttle body.

More fuel makes more heat (Exhaust Gas Temperature), more power, and more RPM.
Less fuel, exact opposite.

Idle is controlled by the amount of fuel that is injected.
Want a higher idle? Inject more fuel.
Want more power? Inject more fuel.
Want more RPM? Inject more fuel.

Making sense?

On a stock truck, the computer is programmed to defuel above 20PSI. So if you adjust your wastegate for 30PSI,, the ECM will pull the power down, attempting to maintain 20PSI at WOT. You will need a boost fooler to get more than 20PSI out of your truck.
As StakeMan said, on '01 Auto trucks, the computer defuels them. You can see this at the track very easily. (building boost at the line)

From a power standpoint, de-fueling is bad. Sometimes de-fueling is neccassary to maintain a safe EGT.

Merrick Cummings Jr

 

My 01' will defuel when i reach around 25-27 pounds of boost. I gained this boost when i swapped on teh turbo from an 01 HO 6sp. and blocked the wastegate on it. I hear that BD makes a type of electronic controller that will override your computer and not defuel the truck. I cannot think off the name of it off teh top of my head, but i have heard that it can cause other problems with the computer when your run it. This defueling is annoying, but since i'm still running the stock auto tranny i'll deal with it.

 

Am I correct that the EZ stops the defueling?

 

The EZ only stops the boost based defuel.

The BD R.A.D. stops defuel but is only good for the track since it kills the tach.

 

[quote author=Haulin in Dixie link=board=4;threadid=20840;start=0#msg195725 date=1065908990]
Am I correct that the EZ stops the defueling?
[/quote]

As Stake said, it only stops the boost defueling.

The EZ adds fuel lower in the RPM range, and provides timing. It's good for 60HP, but only ~40HP at HP peak. make sense?

Merrick Cummings Jr

 

So how do I increase my boost without causing the ECM to de-fuel?
Would the Turbo-Master boost control work?

 

You will still need to "fool" the computer into thinking it is making less boost than you actually are.

Even though you can produce 35PSI boost, a boost fooler will "fool" the computer, and only allow it to see the amximum limit of ~20PSI.

The Turbo Master will only control the mechanical part of the turbo limiting boost.

So, actually, you could use both,, the "Boost Fooler" to fool teh ECM, adn a Turbo Master to bring up the boost.

Merrick Cummings Jr

 

figure 9:

My son and I both had "defueling problems" with our
Dodge 24 valve CTD. My 2002 is actually worse than
my sons 2001.

We both are running the "BD R.A.D. Device" which will
stop the defueling problem. They work very well, but as
"StakeMan" said it will cause your tach to stop working
(just temporarily) and will set a "Check Engine Light"
(also temporarily). When we drag race our trucks this
is a "must use" device! "Stakeman" uses his for drag
racing too!

-------
John_P

 

So I can use a Turbo-Master, Edge EZ and a boost fooler all at the same time?
What I want is 29psi of boost without defueling.

Will the increase in boost pressure help lower egt's while towing?

 

The Edge EZ has a built in boost fooler, and the Turbo Master will allow you to adjust the boost to the desired level. The extra boost and timing will help lower your EGT's.

 

For those of you racing with the BD RAD... how much of a difference have you seen using this at the track? I'm interested in this, but haven't heard much about it until recently. Any guesses on how much it would help my truck?(sig shows my bombs.)

Thanks,
Chris

 

It took .2 off my times. I can feel my truck defuel on the street when the R.A.D. is turned off.

 

Stakeman,

Thanks for the reply. So if i'm reading you right, it made the difference between a 14.1 and a 13.9? that's pretty significant i think. So would i be able to run around a 13.80 with this do you think? I always noticed my truck really feels like it falls off at high rpm's, then regains a lot of power as soon as it shifts. Is this what the RAD changes?

John_P, what kind of difference has it made for you and your son, if you don't mind me asking.

Thanks much,
Chris

Edit - Is this not what the Edge Drag Comp does? I know that it supposedly fuels all the way to 3200 instead of cutting back from 2700 on. So if i change to a drag comp, would the BD RAD still be beneficial?