Obtaining MAF transfer functions/calibration charts

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littlej
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Obtaining MAF transfer functions/calibration charts

Post by littlej » Mon Jun 06, 2011 8:57 am

HI there,

New to the forum, Looks like a great place with lots of good info swimming around!

So, i was wondering,

Im setting up a flow bench and im looking for a MAF sensor i can buy that comes with a calibration chart or transfer function.. Or even better, how can i get a calibration chart for a MAF sensor i have in hand?

I can give the part number, but its the one from the two litre Ford scorpio, also used on the 2.0 escort and 1.8 diesel transit van. All of them being mid 90's..

help or suggestions anyone? :biggrin:


EDIT:

Im asking here not because im trying to rip on your knowledge, im asking because im doing a post grad in automotive engineering and dont have much budget (calibrated orifices are expensive and there are loads of MAF sensors around waiting to be used) I also plan on making an effort to add to this forum if i can with things ive learned, n maybe an SAE paper if i come across a relevant one..

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cgrey8
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Re: Obtaining MAF transfer functions/calibration charts

Post by cgrey8 » Mon Jun 06, 2011 10:25 am

First off, how much air do you NEED to be able to measure? If the MAF you have is from a small 4-banger, it's upper limits may be fairly low.

Assuming the MAF you have is big enough, you'd need a definition file and tune that originally used that MAF. If it is from a fairly unpopular car (from a performance/modification aspect), then you may not have much luck finding a definition file or tune that matches the MAF you have so getting it's curve may be more difficult than simply installing some software and extracting out the MAF curve from a tune.

The next option is have your MAF flowed on a flow station. If you don't have a company that does MAF flow testing near you, this would involve you packaging up your MAF, sending it off to somewhere like C&L, and paying to have it flowed. Then pay to have it shipped back. But that could get expensive for a MAF that you later find after being flowed isn't big enough to do what you need in the 1st place. Shipping alone will run you probably $20 to-n-from. Flow services are usually a minimum of $30.

Before I did that with an unpopular/unknown MAF, I'd go on eBay and buy a 90mm Lightning MAF (aka LMAF).
90mmLMAF.jpg
(7.99 KiB) Downloaded 1362 times
Looking on eBay, those MAFs are relatively cheap (~$75 inc shipping), they have a flange made onto the MAF for easier mounting to fabbed-up stuff, and have very well known flow curves. Their internal architecture is also much better than older design MAFs so their accuracy won't be as affected by your flow station's intake track. I think some LMAFs have a built-in Intake Air Temp sensor in them as well, which is needed to convert Mass-Flow to CFMs (verify this before assuming all LMAFs have an IAT sensor). And because they were the MAF on a performance-oriented vehicle, they flow a LOT of air. Like anything, there's going to be error. But I believe this would probably be a fairly low error and the most economical way to go...assuming the alternatives are more expensive than a $75 MAF.

The cheapest, but most time consuming option is if you can find a junkyard to pull MAFs off of, then you could rummage around on the EECAnalyzer.net website looking around at what definition and tunes are posted in the download section. The tune will contain the MAF curve of the MAF used on the vehicle that ran that tune. You can then cross-reference those tunes to what vehicle the tune was used on. With a long list of vehicles, go find that MAF in the junkyard, on ebay, or on Craigslist. But by the time you did all that, you would probably come out cheaper just buying an LMAF off eBay.
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decipha
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Re: Obtaining MAF transfer functions/calibration charts

Post by decipha » Mon Jun 06, 2011 11:16 am

post the bin and i'll yank the maf transfer

littlej
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Re: Obtaining MAF transfer functions/calibration charts

Post by littlej » Thu Jun 09, 2011 9:06 am

sweet...

Im not so worried about the upper limit of the MAF. More the lower limit...

You know how MAF sensors drop off below a certain range and flatten out above one?
The engine I want to get the volumetric efficiency curve for is a 1.6 liter four cylinder. Were runing it on a dyno with a DTA ECU and that one doesnt have a readout for MAF's.. So basicly im looking for a MAF to stick on the intake tract and measure the mass air flow and engine speed and determine the volumetric efficiency..

So i was wondering if the LMAF (the 90mm one) is too big? Im gonna ask for the transfer function to see how low it goes.. The MAF i have is an older 65mm.. I think i have a transfer function for it and it goes down to 1 lb/minute which is quite low, but good to have a wide range.

after im done with the engine, ill probably set up a flow bench and measure the flow through the valves cuz weve got a second engine ive stripped..

what u guys think?

littlej
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Re: Obtaining MAF transfer functions/calibration charts

Post by littlej » Tue Jun 28, 2011 6:07 am

Hi there

lightning MAF is in the MAIL!

thanks for your advice

Ive just been looking at the adapter cable for the MAF. around 30$?????

I have a few of those plugs laying around i think

anyone know which pin is which on the lightning maf?

its four pin to 12v+ 12v- signal and signal ground.. just afraid of pluggit in for trial n error in case i fry it..

littlej
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Re: Obtaining MAF transfer functions/calibration charts

Post by littlej » Thu Jul 14, 2011 6:52 am

can anyone check this for me?

i have the transfer for a lightning maf but im sort of unsure of it.. ill attach it in an excel file and as i got it from the manufacturer..
Attachments
LMAF%20in%20KG_hr.jpg
(103.13 KiB) Downloaded 1211 times
lightning maf transfer.xlsx
(45.92 KiB) Downloaded 267 times

rdesalis
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Re: Obtaining MAF transfer functions/calibration charts

Post by rdesalis » Thu Aug 10, 2017 1:58 am

Hi all,
Did you find a solution that worked? I have the same problem for a prewar car where I want to measure airflow for a test, not for EEC control. If there is a MAF sensor out there that I can buy, especially in Europe, suitable for engines around 100hp, with a known transfer function I would love to know!

LeadHead
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Re: Obtaining MAF transfer functions/calibration charts

Post by LeadHead » Thu Aug 10, 2017 12:29 pm

Something like a stock foxbody Mustang sensor would give you acceptable resolution I think.

jsa
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Re: Obtaining MAF transfer functions/calibration charts

Post by jsa » Thu Aug 10, 2017 9:48 pm

MAF transfer for the Escort Cosworth is known.
Cheers

John

95 Escort RS Cosworth - GHAJ0 / ANTI on a COSY box code
Moates QH & BE
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