MustangGT221-Trucks with SD may be "batch" injected, but not all cars using SD are. Mustangs, for example, were SD and SEFI.
And in general, SD will produce better performance in stock form. This is common knowledge among Mustang enthusiasts. If for no other reason, than the screen on a MAF meter restricting air. I've read in several publications, from the Motor Trend genre, to Muscle Mustang and Fast Fords. It used to be something we all just "thought", when the '87 and early '88 cars would run a little better, but at that time it was just a myth. But now it has become common knowledge. Usually the numbers are minimal, something like 5-7 horsepower.

It was also one of the things that contibuted to the decrease in the HP ratings if the 5 Liter Mustang in '91.

But this is a truck forum, so Ill shut up now....sorry

 

Well, according to my ford EFI books, the mustang SD system is not SEFI. This is sourced from my books, "How to Build & Modify Ford Fuel Injected 5.0L V-8s", "Ford Windsor Small-Block Performance" and "How to Tune & Modify Ford Fuel Injection".

And also according to those books, MAF is more efficient and better at making power. The little screen on a MAF meter doesn't restrict much airflow, the air filter does a lot more. I put a MAF conversion kit on my truck and it made a very noticeable power increase from just the conversion. The trucks and 5.0 mustangs have the same EEC-IV EFI system.

Think about it, the SD system is pre-programed with certain engine parameters. It says to itself, I have X amount of throttle, Y amount of vacuum, Z amount of load, and with a few other sensors inputs decides how much fuel to put into the engine. It does not know how much air is really going into the engine, which is therefore a little inaccurate for making the air/fuel ratio perfect.

The MAF system directly measures the amount of air entering the engine. It is able to know exactly how much air is going in, and what amount of fuel to add. The only time MAF is not considered superior is in high hp 5.0s that are full out race cars. The race team has their own computers to burn/program computer chips for the SD. They'll change the programing often, even just based on the weather, so they're very critical. They do mention that they prefer the SD in that situation so they don't have the MAF sensor's whatever amount of restriction, but this is full out race teams with gobs of money to spend on computer chip programing, and worry about every single hp they can get...this is not realistic for us.

SD is not more efficient/powerful than MAF in stock form. Why do you think they swapped from SD to MAF in the first place, its on everything now...the reason they did is because MAF creates lower emissions, lower emissions means a more efficient/powerful engine. The big power maker between the two is the multi-port (sd) vs sequential (maf) injection.

If you really want to know the truth about Ford's EFI...get those books. They're available from Motorhaven.com.

There is a thread in the 87-96 forum about MAF conversion on the E4OD..check it out.

 

On a Mustang, both the SD and MAF were SEFI. In stock form the SD has a little more power. They have a slightly more agressive tune, a different camshaft, and they do not have the tiny stock mass air meter as a restriction. This is true for the Mustangs, and as far as I know, all HO equipped vehicles, such as Lincoln Mark VII. The non-HO engines are batch fire.
Another good reference is "The Official Ford Mustang 5.0 Technical Reference and Performance Handbook".


The general statement that MAF is more flexible and capable is true, and it has the potential to be more efficient and produce more power, I agree with that.

 

BigGreen'77: Agreed, and yes, the 87-88 Mustang DID have more HP (but less torque) than the 89+ HO's that replaced them. There was ~15-20HP difference in favour of the 87-88 and ~10ft/lbs in favour of the 89+. The factory MAF Meter is approximately the same size as the throttle body but looks tiny compared to the housing its placed in, I am about to do the MAF converrsion on my '87 GT for the reasons mentioned above, such as heads/cam/intake....etc, as MAF is much more friendly (read:adaptive) with aftermarket parts than SD is. The 88-89 HO's had a slightly different cam profile and a few other very slight differences.

 

Thats odd, considering they were rated at 300 ft/lbs in '87, and by the time '95 rolled around it was 285.

 

87-88 had 295ft-lbs, 89+ had 300ft/lbs, so I guess it was only a 5ft/lb difference