A9L vs. A9P whats the diff?
 

I think the A9P is for automatic cars.. but not sure.

heres the deal, my car hasnt performed right since I built the engine. It pops back, has a "power band feel" and only ran 106 mph in the 1/4 its a 5 speed and its a 306 w/stock Performer Rpm's 2.02 valves. Lunati 51025 cam stock Gt40 75mm bullet 24# injectors 1" spacer .. when I had my heater core put in my buddy noticed the computer had a HUGE stick that said REMANUFACTURED could this be my problem.. the car drives good just doesnt perform like it should. I have a A9P should I try it or not worth the effort?

The A9P is for a auto. They run a little more aggressive than other computers. I run one in my car.

I think that the A9L has the best timing and fuel tables. The A9L is the computer that everyone wants. If there is a difference in performance I can't see it being much.

Wade

PKRWD posted the list of ECM's out there from best to worst and the A9L was at the top.

I don't know how reputable it is but I have heard that A9P's have more spark and fuel than the A9L's. In a recent magazine when the talked about the history of the 5.0 they were saying "at this time the hot combo was" blah and an A9P to add more fuel. They didn't mention the spark, but I have heard that elsewhere.

In '89 ford wanted the mustang to be able to compete with the other manufactures in racing. to make the automatic as agressive as the manuel it had a beefed up computer that shifted faster and something else that escapes me. i know thats why people want the 89 up auto computers.

I have tried both the A9P and A9L and noticed NO difference

I've heard the same as Smokedawg, that them A9P's have alittle more aggressive tuning due to the auto's. But as far as performance I really haven't seen a difference. On a buddies 4-8 conversion he startes out with an A9P and switched to an A9L and to be honest we didn't notice a difference between the 2...

The automatic computer had nothing to do with shifting in the pre -94 mustangs.

So are you saying someone with a auto tranny can run a A9L?

I believe so. There are some minor differences, but transmission shifting isnt one of them. The AOD up to 1993 is mechanically shifted with no input from any computer.

From what I've heard the difference between the two is just the spark curve. I know you can put an auto computer in a 5 speed car, a friend of mine did it. They say it's supposed to help it out and make it quicker but he didn't see a gain.

Yes you can put a auto computer into a 5 speed car, but DO NOT put a 5 speed into an auto unless you cut and disconnect the wire on pin 30 on the 60 pin connector. I did this and it fried the ECM immediately.