93 Cobra Mass Air question?

The 93 Cobra meter was calibrated the same as the non-cobras (you could say that it's calibrated for 19s). I was in fact, the computer that made the compensations for the larger 24lb injectors. You can put that computer into your LX and use the OEM meter from either car and it shoudl function just fine. You will need to use 24 lb injectors for everything to be happy. If you go aftermarket, you will still want the meter calibrated for 19s and use 24lb injectors. if you plan to use different sized injectors then a custom tune or PMS is in order.

Stock 5.0 and 4.6L 2V Mustangs were originally equipped with 19# injectors. The 5.0L / 5.8L and 4.6L 4V Mustang Cobras came with 24# injectors. When relating MAF sensors and injector size, one of the biggest misconceptions about the MAF system is that the MAF is 'calibrated' for a given injector. This is only true with aftermarket MAF sensors like the Pro-M, C&L / Vortec and Auto Specialties air meters, not the stock Ford air meters. What Ford does, is select a MAF sensor and inform the EEC about it by calibrating the airflow Vs voltage transfer function with data obtained from a flow bench. Then they determine how much fuel the engine will require under worst case scenarios, select an injector size, and put that value into the EEC calibration. The MAF sensor and injector size are basically un-related which means a stock 5.0 Mustang's MAF sensor IS NOT calibrated for 19# injectors - the EEC is. Now that the EEC knows what air meter it has and what injectors are being used, it can correctly calculate how much to pulse the injectors to get the desired fuel flow. In simple terms, here is how the EEC figures out how much to pulse the injectors.

I hope this helps.

Even the aftermarket meters are not calibrated to a specific injector. They're calibrated to send the signals to a given computer that that computer expects to see in combination with a given injector.

In other words:
An aftermarket meter calibrated for 19s for an A9L would be calibrated differently for a computer other than that computer given the same size injector. This is where custom computer tuning and PMSs come in. They provide a way to tell the computer how to deal with a given meter output voltage (using the flow data) and whatever sized injector is being used.

I'm sure that it's all clear as mud now.

Yes... so long as you're not using the Cobra computer. Mass air meters calibrated for Fox bodies and 19 lb injectors will not have the correct voltage outputs for what the Cobra computer is expecting. It just comes down to there being somewhat of an expected standard for Ford applications when you're talking about meters being claibrated for X sized injectors. The Cobra computer takes a departure from what's become known as the norm.

You could use either meter.. it doesn't matter. But you'll have to use the 24 lb injectors. Where it will become a problem is when/if you want to upgrade to a lerger injector (30s for instance). You'll have allot more difficulty finding a meter that will run with 30s and the Cobra computer.

OEM meter (or meter calibrated for 19s)+ Cobra computer + 24lb injectors = Good

Any meter + Cobra computer + Any injector NOT a 24 = Bad (speaking generally)

In order to get a meter calibrated to work with the Cobra and injectors other then 24lb injectors means getting a meter specifically calibrated for use with the Cobra computer and whatever sized injectors you plan to use.

It's a whole hell of allot easier to get a custom tune and adapt the computer to the meter and injectors than it is to go the other way around in an instance where you're using a Cobra computer. If you plan on getting an aftermarket meter... plan on using your LX computer. I believe that it should be an A9L or an A9P. Pretty much the standard when you're talking about what size injector an aftermarket meter is calibrated for.