ty_ty13

iTrader: (42)

in the VE table when you put larger values in, are you putting more air in the motor or are you putting more fuel in the motor?


what AFR do you guys consider Lean and Fat?


what is considered safe?

Thanks,

Tyler

foff667

iTrader: (2)

neither in reality...all your doing is TELLING the pcm where in the powerband your vehicle is more or less efficient...the more efficient the more fuel it will add so in the end you ARE adding more fuel but different then the way your thinking about it.

its all relative...some consider 12.2 fat on an NA car yet others see it as just about perfect...some consider 13.6:1 lean on an NA car yet others see it as just about perfect. Also depends if your talking about #'s on a dyno or numbers on the street.


I'll quote myself from another thread "the term "safe" is all relative when you use it when talking about tuning. Is 30* of timing safe? Is removing TM safe? its all relative."

ty_ty13

iTrader: (42)

so larger values in the VE are adding more fuel?

foff667

iTrader: (2)

-yes.

ty_ty13

iTrader: (42)

i have a blown car and tune on the street what would you consider a decent AFR? no more theoretical answers either

slow

iTrader: (7)

doesn't the VE table have a mass value of airflow?

For a blown vehicle, you want to be around 12.0 or richer.

Ryan

SSpdDmon

iTrader: (10)

The default units for the VE table are (grams*Kelvin/kPa), which to me sounds like airflow. More airflow requires more fuel. Therefore I'd say when you increase the VE table, you're telling the PCM, "This is the amount of airflow the motor will see based on the current temperature and barometric pressure."

Generally for a blown tune, I believe people shoot for an AFR of 11.8:1 for the street.

How much boost are you running?

ty_ty13

iTrader: (42)

maybe the VE is telling the computer this is the certain amount of air you will see at this pressure so then in turn it adds more fuel... when in reality its not really seeing that much air but we program it that way to make it dump more fuel....

i could be way off, but sometimes i feel like i learn more when im involved in a discussion.

RedHardSupra

iTrader: (1)

SSpdDmon got it right--you dont 'add fuel.' it is not your job. all you have to do, is to describe the breathing characteristics (airflow at temp/pressure/rpm) and the fueling is figured out for you, by the computer.