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would there be any benefit to installing a svt maf housing on my zetec compared to my stock one im running the svt snorkel and airbox right now and will be doing the svt header swap
 

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unless ur going for a serious NA build, IE, greater than 175 whp, i don't think so. if you boost, you will run a larger maf and housing than the svt.
 

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Anytime you enlarge the diameter of the MAFS housing, you'll have to tune for the difference or you'll run too lean. Conversely, you could run correspondingly larger injectors (that is, upgrade the airflow AND fuelflow proportionately at the same time) without having to change the tune.
 

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Anytime you enlarge the diameter of the MAFS housing, you'll have to tune for the difference or you'll run too lean. Conversely, you could run correspondingly larger injectors (that is, upgrade the airflow AND fuelflow proportionately at the same time) without having to change the tune.
This is misleading information.. or am I just confused?
I asked a while back if running a MAF housing&sensor calibrated to larger injectors (for instance, the SVTF MAF & 30lb injectors) wouldn't require tuning to calibrate on a regular Zetec..
 

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Whoa.... housing&sensor or housing? The OP asked about the housing. Running an SVT MAFS is a different story....

Replacing injectors and MAFS housing without retuning is one of those things that CAN be done, per se, but SHOULDN'T by most people for a number of reasons...
 

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Well, what's the gain of dropping the stock sensor into a SVT housing(assuming the svt housing is larger) and running larger injectors? Is this only on a 'tuned' application, or is this safe w/stock pcm calibration?
That's what I'm wanting to know.
 

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SVT and standard zetec housings are different sizes. IIRC the difference in size will be detected by the MAF and will cause the ECU to go into safe mode (or something to that nature) to prevent the engine from running lean, and then in turn it will throw a CEL, and possibly cause a drop in MPG and power. i read that in my performance repair manual awhile back. i think it was chilton xtreme or something to that effect. i apologize if my terms are not exactly correct as im awful at remembering the names of people, books, places, famous battles, and technical terms, but the gist of it is there.
 

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SVT and standard zetec housings are different sizes. IIRC the difference in size will be detected by the MAF and will cause the ECU to go into safe mode (or something to that nature) to prevent the engine from running lean, and then in turn it will throw a CEL, and possibly cause a drop in MPG and power. i read that in my performance repair manual awhile back. i think it was chilton xtreme or something to that effect. i apologize if my terms are not exactly correct as im awful at remembering the names of people, books, places, famous battles, and technical terms, but the gist of it is there.
I don't think this is correct. The PCM has NO IDEA how large the MAFS housing is.
 

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the same thing happens with some cheap ebay brand intakes. if the size is off by even a little bit you get the same issue
 

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Or the size can be off by a lot! My ebay CAI has a diameter nearly the same as the SVT housing! I think there is a benefit to using an SVT MAF tube, but not without supporting mods and proper tuning.
 

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OK.... heres the skinny.

This is NOT "old" the Mustang world you can not change injectors to match the MAF without tuning.

If you change the MAF housing size you need a tune.... going to a larger MAF houseing will cause the sensor to read lower air flow than what you actually have which in turn will definitly cause a lean condition.

Changing to a larger injector will pretty much cause you to run insanely rich...almost undriveable rich even if you have a larger MAF housing.

Now you can go slightly larger on the housing and make some power, but thats still because you're running lean.

Running calibrated MAFs are STONEAGE tech for people that dont comprehend tuning.
 

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spot on 03OrangeSVT!!!!!
 

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OK.... heres the skinny.

This is NOT "old" the Mustang world you can not change injectors to match the MAF without tuning.

If you change the MAF housing size you need a tune.... going to a larger MAF houseing will cause the sensor to read lower air flow than what you actually have which in turn will definitly cause a lean condition.

Changing to a larger injector will pretty much cause you to run insanely rich...almost undriveable rich even if you have a larger MAF housing.

Now you can go slightly larger on the housing and make some power, but thats still because you're running lean.

Running calibrated MAFs are STONEAGE tech for people that dont comprehend tuning.
I've never tuned the Ford ECU, but I have tuned several others, and on those, a small change in maf housing diameter (one that affects flow <10%) would be effectively compensated by the long term fuel trims in both OL and CL operation. Most other ECU's allow +- 25% fuel trims to allow for differences in fuels, etc, and have 4 or more maf ranges to store unique trims. Does the Ford ECU operate this way?

Injector changes present another level of tuning, particularly since the latencies are unique.

But, assuming injector latencies are equal (which is rarely the case), logically, you could change maf housing (larger) and injectors (larger), and end up with a decent running car (relying a bit on fuel trims), assuming you could competently match the flow increase of the maf housing with the flow increase of the injectors.

no?
Jeremy
 
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