nmcgrawj said:
Well cant higher pressures make the injectors act "bigger" than what they really are at a given pulsewidth?
You are absolutely correct Nate
Allow me to ramble on for a while if you please and I promise ...... it will make a point about several methods of tuning
...... I hope
Lets consider three examples
1) Ford tunes our Stangs with the pcm ...... nuff said
2) Us hot rodders think we are tuning when we do stuff like:
a) Adjust the throttle body blade stop screw
b) Twist the dizzy
c) + or - fuel pressure
d) Use maf/inj's that are
caled to each other
3) EEC Tuner/Tweecer peeps try and tune as Ford did but attempt to use values that more accurately represent what has changed due to the new hot rod parts that have been installed.
#1 has to be the most accurate ... would you not agree
#2 gets the job done ... has its limits & not much flexability
#3 can be effective ... WHY to change values must be known
When tuning with #3, you are striving for accuracy with things like a, b, & d from above.
Say you got everything all set and your tune is great
If you do any one or more of the below
Up the fuel pressure
Turn the tb screw
Twist the dizzy
Delete emissions equip
Install matching caled maf/inj's
The pcm now can't understand what happened
Any mechanical changes
are counter productive
to your previous tuning efforts
It is worth noting here the same kind of deal goes on when you make these kinds of mechanical adjustments on a stock Stang. The pcm can only deal with so much of that kind of stuff before it freaks and drivability goes out the window
I'm done now
Grady
