computer swap

89streetbeast

New Member
Dec 4, 2006
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horton,ks
after reading all the threads about the cobra computer my eyes are mush and im still confused on a couple things.

1) is it still possible to run larger injecters with the 93 cobra computer say a 30lb injector if it is tuned or am i better off swapping back to the A9L or P, or am i stuck with 24's with this cobra ecu?

2) from what i read all i would need to do for a swap back to A9? is to get an MAF from like ProM calibrated for 30lb'ers and have the ecu tuned for that setup?

am i close on these or am i still in the woods lol

thanks
 
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All the aftermarket MAF meters are tuned with the assumtion that you're using a computer designed around 19# injectors.

Because the cobra computer is designed for 24# injectors that means all the different MAF meter variations aren't going to be accurate with that computer

Basically aftermarket meters make the computer run leaner than it otherwise would.

The cobra computer is already tuned to run a little bit leaner _if you had 19# injectors installed wtih it_

So, instead of an A9 with a 30# meter for 30# injectors.. you would do _something like_ a cobra computer, with a 24# meter for 30# injectors.

This might get you close, but might also prove to be more of a tuning hassle than it's worth though.
 
this is one area of cars i have no smarts on lol. granted the car was a carbed setup it wouldnt be so bad cuz thats all im used to. only thing i've done to this car electronic wise was put the cobra computer kit on it, msd coil and another stock distributor. other than those little things im lost.

plus my math skills suck:rlaugh:
 
after reading all the threads about the cobra computer my eyes are mush and im still confused on a couple things.

1) is it still possible to run larger injecters with the 93 cobra computer say a 30lb injector if it is tuned or am i better off swapping back to the A9L or P, or am i stuck with 24's with this cobra ecu?

2) from what i read all i would need to do for a swap back to A9? is to get an MAF from like ProM calibrated for 30lb'ers and have the ecu tuned for that setup?

am i close on these or am i still in the woods lol

thanks

1. There are very few aftermarket MAF meters calibrated for larger injectors & the Cobra X3Z computer.
However, if you are going to get the car tuned, then it does not matter what size the injectors and MAF are, as long as they are appropriately sized. Your tuner will be able to adjust the MAF settings, and the Injector settings separately.

2. To change from a cobra setup you will need to change the computer/MAF&MAS/injectors (or get a calibrated maf for the injecotrs).
Again though, you mention getting the computer tuned. If you are going to a tuner, there is NO need to concern your self with calibrating the MAF with the injector size.


Is a dyno tune set in stone for this project?

Keep in mind that mismatching parts, hoping that they get you 'close enough' can be very dangerous. Going lean at wot can destroy your precious motor.
If you are lucky with a parts mismatch the car will run, not run well, just run.
If you aren't lucky... You'll be picking up pieces of your engine off the street/strip.

The advantage of the Cobra X3Z swap is that it allows a Mustang to run 24lb injectors, without an aftermarket MAF (which may or may not be accurate), or getting a custom dyno tune.
There is no significant power to be gained with an X3Z conversion, but the drivability with 24lb injectors will be stock quality.

If the car is getting tuned, it will not matter which computer you start with, so stick with what you have.

jason
 
ahhh, i gotcha. after i read all them old threads it was getting confusing lol but i got it now. since i've owned the car in 2001 its never seen a dyno or had a tune, so it may be time :D

Not to discourage a dyno tune, but...

Whether or not you need a tune is not really time dependant.
It will depend more heavily on what modifications have been made.
A H/C/I swap paired with a MAF/Injector upgrade, will be more likely to require a tune, especially in the idle and cruise ranges.

my thoughts anyway,
jason
 
right now the only thing that hasnt been swapped was the heads, but they are ported pretty good. the car runs great dont get me wrong lol. but i think there is more potential with the stuff that i have than what its acting like. when i bought it back in 01 it was bone stock down to the gears lol. this is the 2nd time i've owned the car. first time it just had the ported heads, aftermarket intake and cam with the stock TB and the cobra computer kit with MAF and injectors. after i got it back the 2nd time, the guy put a 75mm bbk TB on it so i dont know if the AF ratio is messed up somewhere. right now it idles at 45psi with the vacuum line unhooked, around 41 - 42 with it hooked up. dunno if that has anything to do with it or not.
 
heres a little better idea of what I and He did to the car



Mods I did :

89 GT: 306,TRW forged pistons,ported and polished E7 heads w\trickflow upgrade kit,Crane Cam 2031,1.7 Crane RR, Typhoon intake,Cobra computer kit w\24lb injectors and 70mm Maf,AC eliminator kit ,(flowmaster catback - gone),2 1/2" H-pipe3.73 gears,detroit locker,electric fan




Mods He did:

75mm BBK TB,BBK adjustable FPR,NOS inline fuel pump,Hooker Comp Longtubes,sporting turbo muffs now,C6 tranny built w\reverse manual valvebody and transbrake,3000 stall,B+M Megashifter


im not sure since i took the NOS brand nitrous kit off (if that changed anything)with the NOS fuel pump still hooked up or not. all the vacuum lines are back to stock configuration. car was originally a 5 speed if that makes a difference.
 
If you are looking for more power, then a dyno tune would yield good results.
The only part of your combo that would be a major concern would be the cam, but I don't know the specs on it.
If the duration is fairly large and there is a decent overlap, then you could also see driveability and idle improvements.
Are you unhappy with the idle quality?

Another option to consider for the DIY guys is a personal tuner that will allow you to tune the computer yourself via a chip.
If you are interested check into the 5.0 Tuning sub forum here, as there are some good links on the available options for the EEC-IV Mustang.
TwEECer, Moates, PMS, AEM - all are fairly well entrenched in the Mustang world.
 
specs on the 2031 cam:

advertised dur: 276intake, 286 exhaust
factory rocker lift @ 1:59:1: 513intake, 529exhaust

lobe seperation is 112*

timing is set at 16* ATDC with spout unplugged if that might have something to with it , i have no clue.

the cam for having the 1.7 rockers on there actually idles smooth. since i have a 3000 stall on there its peaking its tq curve and hitting the hp curve at the same time. which is a good thing i suppose:shrug:

it just feels to me with all the parts thats on the car it just isnt performing like it should. unless im expecting too much from it :rlaugh:
 
i know i know lol, im more of an old school person. this car was my first fuel injected car actually lol. dealt with a 90 probe 4 banger, 94 thunderturd (pos) and the 92 vic we got now which is the wifes daily driver lol. after all that bs with the bird i got to thinkin real hard last night and just decided carb was better for me since i know about it more than fuel injection. but, oh well, guess i'll have to pawn off my fuel injection stuff then lol.

laters