I'd like to put the 03 cobra injectors and 03 Cobra MAF meter in my 99 Cobra when I put the Vortech on. Is the 03 MAF already calibrated for the injectors or do they make the changes in the ECM?

thanks
Mark

Well, stock meters aren't calibrated for anything. All they do is meter air. It's all in the EEC after that.

For example, 94 GTs and 94 Cobras had the same MAF. But they had different injectors. All of the "tuning" for the bigger Cobra injectors was in the EEC.

The only meters "calibrated" for injectors are aftermarket. And by calibrating it, all they do is this.. If you are going from 19 to 42 lb injectors, they just take the whole meter calibration and multiply it by (19/42). If you just plugged in the injectors and went, basically you'd be spraying 42/19 too much fuel.

So they trick the meter and the car into thinking only 19/42 air is coming in so it shoots the right amount of fuel. That's a BAD thing to do, since it throws off the load tables, which are what nearly all of the timing and fuel tables use for lookups. So then you have to go and try to re-program all that crap so it works OK, even with the screwed up loads it's reading.

MAF's suck IMO. /pee/ I rather have a MAP based setup like MOTEC or something..

 

ttt

 

ok, so i bought a 95mm pro-m.... which at the time was going to be used with 55lb injectors, now I'm going to set up to 72lb injectors.

So now going to a larger injector. Can the computer be tuned to work with the 95mm maf still or must I get it "recalibrated" for the larger injectors.

And if having the meter "calibrated" is the wrong way to do it.

who does it the right way? and is my meter already raped if it was calibrated for the 55's?

How do I get an uncalibrated meter so someone can tune it throught the computer?

few questions come to mind after reading this post

 

You can take the flow data sheet from the Pro-M and use a device like the TwEECer to tune for it (set MAF flow points and injector parameters). As long as you have the flow points and a means to provide (and tune) info to the EEC I do not believe you need to "recalibrate" (it supplies a certain voltage at a specific amount of airflow / temp).

IWRBB - how can a MAP sensor (Manifold Absolute Pressure?) be used to meter fuel?? Dunno much aboot other systems (having enough fun learning the EEC). What gets done to "tune" an MAF? Do they just adjust resistance, etc to get to a specific output curve that will make the EEC happy (as thoug it were reading a stock MAF and stock injectors)?

IMO the MAF works great when 1) it's a decent MAF and 2) it's (the engine management) configured correctly. My move to a 90mm Lightning MAF and 30# injectors was flawless (with the TwEECer).

Don

 

IWRBB - how can a MAP sensor (Manifold Absolute Pressure?) be used to meter fuel?? Dunno much aboot other systems (having enough fun learning the EEC). What gets done to "tune" an MAF? Do they just adjust resistance, etc to get to a specific output curve that will make the EEC happy (as thoug it were reading a stock MAF and stock injectors)?

IMO the MAF works great when 1) it's a decent MAF and 2) it's (the engine management) configured correctly. My move to a 90mm Lightning MAF and 30# injectors was flawless (with the TwEECer).

Don

Well, the MAP is used along with other stuff to measure airflow. Fueling is left to the EEC based on airflow. GM's use MAP setups. LT1's use no MAF, I dunno about LS1's. The amount of air being drawn into the engine is a good indication of how much power it is producing; and the more air that goes into the engine, the lower the manifold pressure, so this reading is used to gauge how much power is being produced.

MAF's are great, until you peg them. Then they suck. You can't peg a MAP sensor.

To tune the MAF, they just adjust stuff in the electronics so the voltage is scaled like I wrote up top.