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MAF - Some ideas
Posted: Tue May 27, 2008 4:03 pm
by karism
Helo there,
I had a look at the stock MAF the other day.
Looking at the Z32 vs CA18 MAF ,the obvious difference is the size of the main tube.Looking closer at it i saw that the Z32 is a little different,with the probe being in the main tube measuring the amount of air,and not "isolated" in a seperate passage like the stock MAF.
Looking down the main tube,there is no restriction it,just the basic size of the the tube being very small.
What if i got my hands on an extra MAF ,took out the inside and mate it to a large size main tube.
In theory ,the maf should work like normal,but the main tube size will be big enough for higher HP.
Obviouslly when changing over to a Z32 MAF,the K value on the ECU needs to be changed to suite the new MAF.If i use the stock MAF in a higher flowing main tube,i SHOULD be able to go with the factory K setting
Ideas , oppinions?
Please chime in
Karis
Posted: Tue May 27, 2008 4:28 pm
by ChemCool
At this stage I say the following: the slightest voltage change from the different afm setup and the car needs to be retuned.
Good idea to make the tube bigger, but re tune there after I would say. I tried the s14 afm with no good results on the s13. Nope, not lekka.
Three wires and four wires compared.
Chem
Posted: Tue May 27, 2008 5:10 pm
by karism
Thanks for the comment.
I agree it will probably have to be retuned in the end,but i do think that it will at least be "closer" to the stock tune
Posted: Wed May 28, 2008 8:49 am
by Guy
You would have to retune, the old sensor in a new bigger pipe will likely be as far off as the z32 maf.
I'm not sure if its the K value or if there is another maf table that will have to change though, still just learning anout these ecu's.
The Ford guys in the states switch the maf into bigger tubes all the time on turbo's or supercharged focus's and mustangs. They either retune the maf calibration in the ecu or sometimes also use the Diablo MAFia to adjust the maf output.
So yeah it is a mod that will work but it will require retuning.
Posted: Wed May 28, 2008 9:08 am
by karism
Thanks for the comment.
I thought some more about it last night ( i mostly cant sleep at night,so i think about all sorts of random stuff)
If i keep the ratio between the metering tube,and the main tube the same ,it should work. I`am pretty sure that the ratio between them,is the K Value that needs to be retuned.
Hmmmm.

Posted: Wed May 28, 2008 9:41 am
by Doctor G
Are you saying you want to take the stock maf which has a ratio of say 20:1 between the big hole and the small hole (with the hotwire) and fabricate a pipe that has a bigger "big hole" and a small hole with the hotwire, with the ratio the same between the two new holes?
Somehow I don't think it will work. The Z32 MAF for example has no "small hole". The hotwire is simply in the middle of the big hole.
Therefor I am sceptical about the K-value being the ratio of the two holes.
It's a good idea to go bigger on the MAF but you will require a retune regardless of how you go about it.
Posted: Wed May 28, 2008 10:20 pm
by 300sx
have to agree, dont see how you can do this without a retune..
i do think its a non issue nowadays though..
grab a z32 maf of ebay, download one of the many avaidable software packages off the net, put your ecu chip image through the software, hey presto its done..
its this friggen easy these days...
Posted: Thu May 29, 2008 7:09 am
by veecee
if you think about it, the logic isn't sound.
why would you want to install a bigger maf - so that you have more power.
so then the question becomes "why WOULDN'T you want to retune it???"
Posted: Thu May 29, 2008 10:00 am
by karism
Hahaha.
Ok,you guys have convinced me.I will then retune it!
So technically,it should be possible to do it,and it will work.Needs to be retuned though!

Posted: Mon Jun 16, 2008 9:46 am
by Pinkfluffybunnys
The Voltage and the VQ maps will be incorrect.
I have already tried this you will need to create a custom VQ Map and that is almost impossible because you will need to know how much air is entering at each voltage returned from the MAF all 64 stock entries.
Also the Max HP rating of your maf installed in the new housing.
If i keep the ratio between the metering tube,and the main tube the same ,it should work. I`am pretty sure that the ratio between them,is the K Value that needs to be retuned.
incorrect the K value will need to be change just to correct you fueling and you will need a wide-band to do this, The VQ map work based on voltage and returnes a TP value to the ECU.