Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: thunderjet302 on July 09, 2008, 12:07:13 PM

Title: 93 Cobra MAF myth?
Post by: thunderjet302 on July 09, 2008, 12:07:13 PM
Ok who here can prove or disprove this. I have done some searching and have come up with 2 *facts* regarding the 93 Cobra 70mm MAF:

1. The MAF is calibrated the same as the stock HO 55mm MAF (ie for 19 lb/hr injectors) and the only reason that the Cobra computer handles 24lb/hr injectors is because the computer is programed to, not the MAF.
2. The 93 Cobra MAF is calibrated to 24lb/hr injectors.

So which one is right? The reason I ask is I have access to a 93 Cobra MAF for cheap (ie FREE :banana: ) but I don't want to get it if it won't work with my 19lb/hr injectors. I know a 70mm MAF from a 92-94 Vic, GM, or Town Car works but I have to grind down the mounting , where as the 93 Cobra one bolts right in.....
Title: 93 Cobra MAF myth?
Post by: 88BlueBird on July 09, 2008, 12:38:22 PM
For all Fords the PCM is programmed to work with a specific MAF.  The MAF has a unique transfer function (mass air flow vs. voltage) that is programmed into the PCM.  A lot of companies like Pro-M have founds ways to calibrate their larger bore MAFs to perform like the stock MAFs without the airflow restriction.
Title: 93 Cobra MAF myth?
Post by: TurboCoupe50 on July 09, 2008, 03:20:57 PM
Get the Cobra, swap the electronics...(guessing this will work, should be no problem if the internal configuration is same)...

The Cobra MAF has a unique calibration, can only be used with the matching Cobra EEC....
Title: 93 Cobra MAF myth?
Post by: thunderjet302 on July 09, 2008, 04:18:07 PM
Quote from: TurboCoupe50;226615
Get the Cobra, swap the electronics...(guessing this will work, should be no problem if the internal configuration is same)...

The Cobra MAF has a unique calibration, can only be used with the matching Cobra EEC....


That sounds like a plan. Since it's free what the heck. I was going to swap the electronics anyways.

Also from what I've been reading the MN-12 5.0 guys swap in the 70mm MAF housing from 94-95 3.8 and 4.6 T-birds. Since I have a 3.8 T-bird sitting around ;) I might try it to see if it works in a FOX.
Title: 93 Cobra MAF myth?
Post by: TurboCoupe50 on July 09, 2008, 07:39:13 PM
Quote from: thunderjet302;226627

Also from what I've been reading the MN-12 5.0 guys swap in the 70mm MAF housing from 94-95 3.8 and 4.6 T-birds. Since I have a 3.8 T-bird sitting around ;) I might try it to see if it works in a FOX.


They're screwin' up then... My '95 LX ran rich as Hell(cold, it blew black smoke like a Diesel) on a 55mm 5.0 meter, which tells me a 70mm would be lean on a 5.0...

Went to U-Pull-It and got a meter from a 94 3.8, ran fine...
Title: 93 Cobra MAF myth?
Post by: vinnietbird on July 09, 2008, 07:50:55 PM
I have got 70mm on mine.No smoke,but my exhaust tips are all nice and black and nasty.Do you think the 55mm would be better?Would the '94 3.8 meter be better,and finally,is there another Ford with a meter like the '94 3.8?
Title: 93 Cobra MAF myth?
Post by: slicksport88 on July 09, 2008, 10:36:00 PM
Quote from: vinnietbird;226667
I have got 70mm on mine.No smoke,but my exhaust tips are all nice and black and nasty.Do you think the 55mm would be better?Would the '94 3.8 meter be better,and finally,is there another Ford with a meter like the '94 3.8?


Hey Vinnie, I wouldn't recommend downsizing your meter. Your setup is close to mine and it feels stronger with the 73 compared to the 55. I have the slight blackness in the tailpipes that you mentioned but other than that everything's peachy. Just for sh*t's and giggles I'd like to dyno the car and compare the two meters side by side.
Title: 93 Cobra MAF myth?
Post by: Cougar5.0 on July 09, 2008, 10:46:03 PM
93 Cobra meter will run richer - see difference in transfer curves below. Using 55mm electronics in 70mm meter will make it even richer...


Stock A9L____93 Cobra
16.000   856.963      16.000   870.143
4.768   856.963      4.454   870.143
4.443   713.249      4.100   709.700
4.177   611.103      3.900   626.564
3.886   512.505      3.700   549.511
3.544   409.599      3.500   478.034
3.355   356.371      3.300   412.133
3.149   303.144      3.100   351.809
2.910   249.663      2.902   297.060
2.694   207.080      2.706   248.142
2.582   187.310      2.411   185.536
2.450   165.512      2.314   167.033
2.316   145.996      2.216   150.304
2.154   123.184      2.119   134.590
1.989   102.653      2.020   120.396
1.890   92.515      1.921   107.722
1.803   84.404      1.819   95.810
1.691   74.772      1.718   84.911
1.574   64.127      1.617   75.025
1.468   55.509      1.517   65.901
1.321   45.877      1.418   58.043
1.182   37.513      1.317   50.439
1.091   33.457      1.216   43.849
.884   24.333      1.114   37.513
.750   19.263      .913   26.867
.571   14.194      .709   18.503
.000   14.194      .606   14.701
.000   14.194      .499   11.406
.000   14.194      .000   11.406
Title: 93 Cobra MAF myth?
Post by: Cougar5.0 on July 09, 2008, 10:57:56 PM
Quote from: TurboCoupe50;226615
Get the Cobra, swap the electronics...(guessing this will work, should be no problem if the internal configuration is same)...

The Cobra MAF has a unique calibration, can only be used with the matching Cobra EEC....


Not true - anybody can use the 70mm with a tuning device. The 93 Cobra meter should make an A9L car run a bit leaner up top, about the same at & just above idle.
Title: 93 Cobra MAF myth?
Post by: V8Demon on July 09, 2008, 11:03:05 PM
Or you could just get a C & L and be done with it.....Room to grow later....Stock electronics.

If you really want to swap stuff around though, here's the cross reference chart again:  http://www.graphicsdept.com/walbro/product/auto_aft/mass/forda.htm

The Cobra meter was designed for 24's....I've never actually held a stock cobra housing (not that I'm aware of anyway).  Any difference in the metering tube sized between it and say a 94-95 GT meter housing?

http://www.superstang.com/maf.htm
http://www.modularfords.com/forums/showthread.php?t=61987
http://forums.corral.net/forums/showthread.php?p=7661057