My '98 Formula has a MAF, and as I understand it, in simple terms...with an increase in intake air flow sensed by the MAF, the computer compensates and orders more fuel from the injectors. Outside of the norm mods (Long tubes, cam, etc) require tuning tables to be modified but the system still learns to compensate wihin the new tune.

How does the SRT-8 know if more air is being added without the MAF? Maybe O2 sensors seek a certain AF ratio, but would think this would be unreliable? Without a programmable tuner out there, if you add a turbo or supercharger, what prevents the cylinder from going lean? Does the mafless system offer greater range to compensate without a special tune?

Lots of questions, but would like to understand this AWD beast.

Great questions, somebody please answer...

well, from what I understand and have heard, cars comem from the factory tuned to run a lilttle fat. This account for any increases one might get via cai, exhaust, headers. And generally the increase in flow is not enough to make the car run lean. Also, that is what the O2 sensors are for.

The computer will adjust for increased airflow or exhaust changes.

If I'm not mistaken, all fuel injected engines have some way of measuring how much air is being drawn into them.

My '78 (German spec) Porsche 924S and my '79 (German spec) Audi 100 had a mechanical air flow meter. It was basically a plate connected to a lever that was lifted up as the airflow increased. The higher the lever was lifted, the more pressure was applied to the fuel injectors. They were basically all spraying whenever the engine was running. Crude, but it worked.

My '86 Mustang GT had speed density air flow meter that the compputer used to calculate air flowbased on the velocity of the air passing the throttle body. This system was very forgiving of different mods, but was not very accurate. It tended to run a bit rich most of the time. Safe, but not good for ultimate power.

In my '02 Lightning, it uses a mass air flow sensor that basically uses a heated wire element to measure the actual (as close as possible) mass of the air entering the engine. As more oxygen passes over the element, more current is needed to keep it at it's set temperature. This relates directly to the total "mass" of oxygen entering the engine, as opposed to the "volume" of air, which is far from being mostly oxygen. This allows for a much more precise metering of fuel and timing.

In all of these systems, the O2 sensor provides "feedback" to the ECM to fine tune the air/fuel mixture. Most systems also use throttle position, coolant temperature, intake air temperature, and RPM inputs. The more sophisticated systems use knock sensors, transmission sensors, crankshaft position sensors, camshaft position sensors, and exhaust temp sensors, among others. The primary means of determining fuel delivery is still the air flow meter. Although I haven't dug into the GC SRT8 system (yet), I would bet that it has a mass air flow meter to determine how much "flow" is going into the engine. As the level of mods goes up, so does the amount of air going into the engine. Aftermarket air MAF meters allow for mods that excede the capacity of the stock meter's range.

I hope this makes some sense...:D