[G.T. Rags]

i'm reading it out of published books. Nothing was changed internally. Its a change in the stock tune of the car.

[TENGRAM]

Originally Posted by 96GTRagTop i'm reading it out of published books. Nothing was changed internally. Its a change in the stock tune of the car.

if thats what your book says then it is wrong. the A9L and A9P equivelant ECMs were used throughout 89-93. there are no 91-93 specific ECMs.

[superman5.0]

soo despite of what ford says the ratings are actually the same? just they didnt advertise that until 93.. to build hype for the new body style right?

[JBIGBOOTSY]

what does ford say? "a changs in tune" is not an answer. Were the timing maps diffrent, scalers, transfer function, what is diffrent? I can't find any diffrences online. I am verry courious now.

[superman5.0]

i herd that the cam was changed and some other internals like that but never a tune.

[superman5.0]

this is from mustang gt registry and the year by year changes
1989 Mustang GT
Engine:

All 5.0 Mustangs were switched over to mass air from speed density with a small reduction in HP (not yet reflected in the HP rating).

A small camshaft profile change to reduce valvetrain noise with an additional small reduction of about three horsepower (also not yet reflected in the horsepower rating).

1990 Mustang GT
Engine:

Another minor camshaft change, but without compromising power output.

1993 Mustang GT
Engine:

Hypereutectic pistons replace the forged aluminum pistons.

Horsepower and torque ratings dropped for ‘93.

The reduced ratings were influenced by a stack-up of minor mechanical changes and by changes to Ford’s engine evaluation processes.

The changes made were mainly due to emissions, fuel economy, customer satisfaction requirements, a series of mechanical revisions.

Mechanical revisions include:

air intake silencer -- 5-7 hp loss

small camshaft profile change in 1989 -- 3 hp loss

addition of restrictive 55mm mass air flow meter in 1989 -- 4-5 hp loss

also some small exhaust system revisions between 1987-1993

new rating system used in 1993 involving changes in the processes of selecting engines to be tested and also the engine’s state of dress (power steering, alternator, water pump, smog pump)

there is everything just small minor things throughout the years but never any different tuning

[G.T. Rags]

it's in one of my 5.0 books. just says 5.0 mustangs on it.

I'm reading through the other books though, and it's basically saying everything that was just stated.

I feel the 1st book is trying to get away with saying a changing in the programing of the ecu, but in actuallity, it's what was stated above.

I misread the line where it states the years most effected. It says that the actual numbers didn't become official until 93, but affected mustangs were from 91-93.

(i'm tossing book in garbage as wee speek because information in here is totally contradictory as to information in my other books. ie the 5.0 was in the 96 mustang yet i have a 4.6 under my hood.)

[superman5.0]

lol good call on the throw away

[G.T. Rags]

yea, some books that i have are really accurate... on the nose type shit. Then there was this one.......

[TENGRAM]

Originally Posted by 96GTRagTop yea, some books that i have are really accurate... on the nose type shit. Then there was this one.......

i hear ya. i've got a 5.0 book like that myself. seems like there were alot of misconceptions early on so the older the book the more likely it will have some false info