swapping T4MO for A9L computer

Tim35

New Member
Nov 14, 2009
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Charlotte NC
I have a 94 Mustang Road Course Mustang with a Cobra 302. I'm getting ready to put in an E303 Cam. I've been running the stock T4MO computer, and it runs rich at idle all the time (barely idles), and takes about 48 PSI with 24 lb injectors to run at around 13:1 at full throttle - that's with the original cam.

I will be taking my car to the shop for dyno tuning when I'm done. The dyno shop suggested that if I run the stock T4MO computer, it is actually a better computer, but not nearly as programmable as the A9L. He said I may need a chip for the T4MO, which is illegal in the series I race in. Thus, I may be wanting to swap to the A9L, which should not require a chip.

First, I would welcome any additional information on the ins and outs of why to stay with the T4MO or go with the A9L.

Second, he said it would cost about $500 for him to swap the computers (above and beyone the cost of dyno tuning). My understanding is that all you have to do to swap the computers is swap a few wires on the ECM harness. I don't have to worry about the electric fan controls which I understand would normally be an issue as well, since I've already installed a separate fan control system - and then took the fan out completely anyway.

I would appreciate any information on the wires that need to be swapped, and any reason why the install would be complex enough to warrant $500 to make the swap.

I'm exceptionally good with electrics. However, I have to have the information on what I'm working with in a case like this. Swapping wires is baby stuff. Heck, I just got done removing bout 3/4 of the wires in my car, and looking for more wires I can remove, and everything still works right. In other words, don't be concerned that you will be over my head. As long as you say things in a way I can understand it, I can figure it out.
 
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I'd reconsidering taking my car to that shop. The only advantage the A9L has over the T4MO, is that in untuned form, the A9L is more mod friendly. If you're gonna have the car dyno tuned anyway, stick with your computer.

I switched to the A9L myself and it's maybe a 2-3 hour job. But again, waste of money if you're getting the car tuned. I switched to the A9L ($300 for kit and computer) and then had the car SCT tuned ($500). Could of saved myself $300 by sticking with my T4MO.
 
The dyno shop suggested that if I run the stock T4MO computer, it is actually a better computer,

Seeing this makes me say you found someone who you could consider
doing business with :nice:

but not nearly as programmable as the A9L.

WHOA ... Seeing this :eek: :eek:

Be Afraid ... Be VERY Afraid :Word:

Run away and find another place to do your tuning :)
or
Here is a thought ;)

Do it yourself :banana:

Grady
 
I am all about self tuning... BUT.

If you are restricted by the class you want to run, then it may not be a bad idea. Not sure the particulars, but if all you can do to tune is use fuel pressure and timing, you are better off with the A9L. The adaptability in the T4M0 will FUBAR your tune after a while. If you definitely can't chip it, then I don't see how you can make the T4M0 work as well as the A9L with modifications.

Tell me if I'm wrong...

Adam
 
I am all about self tuning... BUT.

If you are restricted by the class you want to run, then it may not be a bad idea. Not sure the particulars, but if all you can do to tune is use fuel pressure and timing, you are better off with the A9L. The adaptability in the T4M0 will FUBAR your tune after a while. If you definitely can't chip it, then I don't see how you can make the T4M0 work as well as the A9L with modifications.

Tell me if I'm wrong...

Adam


that seems to be the key for this situation... the rules on how u an modify the computer....
 
we are missing a piece of this puzzle somewhere , 24s and T4M0 would require a calibrated MAF , so it sounds like you should put the stock MAF back on and get a J4J1 computer since you cant run a chip and the stock MAF coupled with a J4J1 computer would probably cost alot less than doing the A9L swap and should run alot closer air/fuel to what you want , the calibrated meters are notorious for being off , the other thing that I am wondering is if you can run one of those MAF adjusters and use that to dial the fuel in , or is that illegal for your class too ?
 
I still got a problem in the fact this guy is trying to convince you
the 94-95 pcm is somehow or the other less programmable than
the Fox body pcm :notnice:

That my friend ... is just not so :ban:

I dunno :shrug:

I'd have my doubts about that guy ;)

If you did do the Fox body pcm
What about using a 93 Cobra pcm
Did they come with 24's like the 94-95's did :scratch:

Grady
 
No, the 93 Cobra computer would be the same as the A9L in regards to the injector tuning. I heard the 93 Cobra computers are undesireable, can't remember why.

In all Fox mass air cars, the injectors were matched to the correctly cal'd MAF. Either way, there is no way to tune either computer without a chip. Adjusting fuel pressure and timing will only get you so far.
 
No, the 93 Cobra computer would be the same as the A9L in regards to the injector tuning. I heard the 93 Cobra computers are undesireable, can't remember why.

In all Fox mass air cars, the injectors were matched to the correctly cal'd MAF. Either way, there is no way to tune either computer without a chip. Adjusting fuel pressure and timing will only get you so far.

I was under the impression that it will get your "further" with an A9L then it will the T4M0. Is that not the case?

Adam
 
The X3z (fox Cobra) EEC has a slightly lame tune loaded into it (vs an A9*). It's not a super huge deal but worth considering.

But it will allow 24's to be used (to be correct, you need the 93 Cobra MAF, which is 70mm but has unique electronics).

None of the factory meters are calibrated for any injector.