Delta Force tuning software ?'s
#11
Check out the spreadsheet is that the transfer function that I'm looking for?
http://www.vmptuning.com/store/index...=193&parent=30
http://www.vmptuning.com/store/index...=193&parent=30
#12
The actual sensor in a MAF mesasures only a small sample of the air actually passing through the MAF housing--that value is converted to a voltage and sent to the PCM where it looks up that volage in a table (the MAF transfer function) and says "Ah-Ha", "X" kg/h of air is coming in.
For example, with the stock 80mm MAF on my '03 the actual flow area of the sensor is about 64mm˛ and the total flow area of the MAF housing is 3994mm˛--so the ratio between the total flow and the sampled flow is 3994/64 or 0.016 or 62:1 or so.
If I stick that same sensor in a 90mm housing (5450mm˛ total area) then the ratio of the total flow area to the sample flow area will be 5450/64 or 85:1. I.e. 37% (85/62) more air is coming in--but the PCM doesn't know this as it's still using the old transfer function. The result will be a VERY lean mix...
This is why on the '05 and later Mustangs changing the intake plumbing almost always requires a tune. The MAF sensor is mounted into the intake in such a way the the after market intakes ("CAIs") have to built with new MAF housings. If these new housings do not have the same flow characteristics as the OEM housing then the transfer function is screwed up.
This brings up an interesting issue regarding using an '05 sensor in a 75 mm housing. I have no idea what size the '05 MAF housing is, however I assume it's as big or bigger than the 80mm (3994mm˛) housing used on our cars.
Assuming it's 80mm diameter, placing that sensor in a 75 mm housing (3510mm˛) will reduce the total flow area/sensor flow area ratio to 55:1 from the 62:1 of the 80mm housing. this means that if using the stock transfer function the PCM will believe that 12% more air is entering than really is, and will adjust the fueling for that additional aiir--BUT that air isn't really flowing so the mix will be 12% rich.
This then leads to "Why would you want to replace an 80mm MAF housing [stock] with a 75mm housing"--regardless of whether the sensor's signal can be properly mapped by the PCM, a 75mm hole (3510mm˛) will be more restrictive than an 80mm hole (3994mm˛).
Frankly that 75mm VPM housing is a mystery to me, there are several OEM MAF sensors much larger than that, and they brag about the 3" inlet and outlet as though that were some wonderous thing. The inlet and outlet of the OEM MAF on a new-edge 'stang are 3.4" (87mm), almost 35% larger by flow area...
#13
Oh, there is one other issue...
The EEC-V PCM used in our cars has an internal airflow limit of approximately 1700kg/h (3740lb/h). Running n/a @ 12.5:1 AFR this is good for 600 or so crank HP, running f/i at 11.5:1 it's 540 fwHP or so.
When you beyond this limit it is necessary to rescale the air charge scalar, and a few other values. SF does this automatically when a MAF flowing more than 1700kg/h is selected.
Here are the transfer functions of a few "MAFs I have known":
The EEC-V PCM used in our cars has an internal airflow limit of approximately 1700kg/h (3740lb/h). Running n/a @ 12.5:1 AFR this is good for 600 or so crank HP, running f/i at 11.5:1 it's 540 fwHP or so.
When you beyond this limit it is necessary to rescale the air charge scalar, and a few other values. SF does this automatically when a MAF flowing more than 1700kg/h is selected.
Here are the transfer functions of a few "MAFs I have known":
#14
Oh, there is one other issue...
The EEC-V PCM used in our cars has an internal airflow limit of approximately 1700kg/h (3740lb/h). Running n/a @ 12.5:1 AFR this is good for 600 or so crank HP, running f/i at 11.5:1 it's 540 fwHP or so.
When you beyond this limit it is necessary to rescale the air charge scalar, and a few other values. SF does this automatically when a MAF flowing more than 1700kg/h is selected.
Here are the transfer functions of a few "MAFs I have known":
The EEC-V PCM used in our cars has an internal airflow limit of approximately 1700kg/h (3740lb/h). Running n/a @ 12.5:1 AFR this is good for 600 or so crank HP, running f/i at 11.5:1 it's 540 fwHP or so.
When you beyond this limit it is necessary to rescale the air charge scalar, and a few other values. SF does this automatically when a MAF flowing more than 1700kg/h is selected.
Here are the transfer functions of a few "MAFs I have known":
Really? I thought this only affected certain processor codes. I know the 03/04 cobras have this issue, as does the 04 Lightnings and all Ford GT's. You can see in this SCT software that the TF is read in Lb per min but if you multiple by 60 you can see that the TF can go far beyond 3740lb/h. In the SCT software we see this problem on the affected processors around 64Lb/min which would be really close to your 3740lb/h
#15
Really? I thought this only affected certain processor codes. I know the 03/04 cobras have this issue, as does the 04 Lightnings and all Ford GT's. You can see in this SCT software that the TF is read in Lb per min but if you multiple by 60 you can see that the TF can go far beyond 3740lb/h. In the SCT software we see this problem on the affected processors around 64Lb/min which would be really close to your 3740lb/h
As to the TF entries, you can enter whatever you like in the transfer function, it's just that the PCM will ignore any values greater then 1700kg/h. This is well documented in the Ford specific section of Greg Banish's book Engine Management:Advanced Tuning.
Last edited by cliffyk; 03-02-2010 at 06:49 PM.
#16
Was that not the transfer function tables I needed in the link I posted?
you have to click on the link that says HPX tool.xls spreadsheet <----- or this one apparently works lol.
you have to click on the link that says HPX tool.xls spreadsheet <----- or this one apparently works lol.
Last edited by Chris98Gt; 03-02-2010 at 06:53 PM.
#17
AFAIK, all new-edge Mustang GT box codes have this issue, not that I have examined them all. It is a template driven issue in Special Forces, however I have not yet run in to a new-edge template that is differently configured.
As to the TF entries, you can enter whatever you like in the transfer function, it's just that the PCM will ignore any values greater then 1700kg/h. This is well documented in the Ford specific section of Greg Banish's book Engine Management:Advanced Tuning.
As to the TF entries, you can enter whatever you like in the transfer function, it's just that the PCM will ignore any values greater then 1700kg/h. This is well documented in the Ford specific section of Greg Banish's book Engine Management:Advanced Tuning.
In the SCT software on vehicles I have worked with you can not enter a value higher than 63.xlb/min if the processor is incapable of reading the value. Either way I'll check it out tonight.
Steve.
#18
Was that not the transfer function tables I needed in the link I posted?
you have to click on the link that says HPX tool.xls spreadsheet
you have to click on the link that says HPX tool.xls spreadsheet
However on the intro page the comment "In some cases you may need to convert volts to counts or kg/hr to lb/min." is made leading me to believe that the air flow units are lb/h--which makes sense looking at the values.
Meaning that the air flow for the HPX sensor in the 75mm housing, at 5.0V output from the MAF (2650 lb/h), will be quite a bit less than that of the stock 80mm MAF on my '03 GT at 5.0V (a bit over 3000 lb/h).
Last edited by cliffyk; 02-02-2013 at 01:12 AM.
#19
I have both of his books, I will check it out when I get home from work. I thought the book pointed to the fact that this affects only some of the computers out there. One that it mentions it the Ford GT where even at the OE level they are scaling to make it work.
In the SCT software on vehicles I have worked with you can not enter a value higher than 63.xlb/min if the processor is incapable of reading the value. Either way I'll check it out tonight.
Steve.
In the SCT software on vehicles I have worked with you can not enter a value higher than 63.xlb/min if the processor is incapable of reading the value. Either way I'll check it out tonight.
Steve.
I just looked at a 2000 MY Special Forces template and found that the >1700 kg/h scaling indicator is not set...
#20
It also says that it's a direct bolt in for the 05+, would that not lead you to think that it has the same transfer function as the stock 05+, or do you think they just mean that it will bolt in, but still need tuning.