tici

iTrader: (1)

Is it really necessary to have a decel fuel cut off?
What if I eleminate it and let the injectors pulse all the time?

A local tuner told me that it's only a pollution issue. Actually it's better to have fuel all the time. This will cool the engine and cause a richer AFR as soon as you go back on the gas pedal - apparently a good thing (???)

What is your opinion?

gametech

iTrader: (1)

Automakers will do anything to increase fuel economy and decrease average emissions. I doubt those concerns are nearly as important to most hot rodders.

jay_99z

iTrader: (5)

It made a difference in my gas mileage on my last road trip. Had it off on the way there....turned it back on for return trip. I don't see any benefit to turning it off.

RedHardSupra

iTrader: (1)

i've seen few cars with 2-3mpg increase because of enabled dfco.
however, i dont believe in the cooling effect, we're talking about few grams a second max of fuel cooling few hundred pounds of aluminium block that's heatsoaked.

SmaknaSS

iTrader: (1)

I would just leave the DFCO on,... I you just pump the gas a little once on Decel the car will inject fuel again.

tici

iTrader: (1)

The Corvette programs have different setting: higher RPM and higher enable speed.
Is there a reason?

TAQuickness

iTrader: (28)

I think it has everything to do with emmisions and economy. I set my DFCO fairly agressive and my average mileage went up 3mpg.

tici

iTrader: (1)

Do Corvette's have a worst gas mileage that F-Bodies?

horist

don't know the numbers but most likely better since they're lighter

TAQuickness

iTrader: (28)

Stock for stock, I'd say they get about the same. If you were to optimize the tune, I'd give it to the Vette. Corvettes have better aerodynamic traits and are lighter than an Fbody.

sampson

iTrader: (1)

I am seen with very large injector cars (1000-1600cc) street cars, the car will flood and bog if you do not have the decel on.

yobabiesdaddy2001

iTrader: (20)

how does the dfco work?

TAQuickness

iTrader: (28)

shuts off fuel when certian criteria are met under decelleration.

yobabiesdaddy2001

iTrader: (20)

on deceleration after WOT I get a really lean spike. If I left the dfco on what that would stop the lean conditon?

TAQuickness

iTrader: (28)

Best way to see if DFCO is active is to log your injector pulse widths. If they are less than 1ms then DFCO is definately active. When DFCO is active, you will see a lean condition.

dynocar

I cannot think of one reason why I would not want DFCO, I even added it to my maps for my turbo Harley to stop the decel back firing, which my wife no misses.

yobabiesdaddy2001

iTrader: (20)

I am going to log that and check it out. I dont see why you would even want this feature!

tici

iTrader: (1)

With carburated engines there is no DFCO. Is that a disadvance?

dynocar

A carb has automatic DFCO, when you close the throttle plates, no air = no fuel, except for the miniscule amount flowing thru the idle circuits.

yobabiesdaddy2001

iTrader: (20)

why would you even want it on a FI car?