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pimpin since 03!
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Discussion Starter · #1 ·
is this true??? my friend came over... and he said that all you need to do is pull out the censor and make a pipe thats bigger with a flang and bolt the maf censor on the pipe and that would be all you ever need?

is this true ?? seems too easy
 

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yeah....i heard of that also....i think on some of the 240's with ka turbocharging....someone used a pipe and replaced the sensor for more air but he also used bigger injectors....i did not read up on this but a buddy of mine with a 240 read up on it....the bigger opening in the maf allowed more air to come in and injectors spraying more cancel each other out not needing a ecu upgrade....im not sure on this, and this is not based on facts so i advise you to go do alittle search on the 240 forums.....im sure someone there would have an answer.....
 

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What he's talking about is called the MAF hack, a very popular proceedure when turboing the ka24de. The theory is that you take the ratio of your injector size to the inside diameter of your MAF senesor and then replace the maf tube with one that equals the ratio of your new larger injectors.
I am very curious to see if it really works and if anyone has tried it on our sr20's. Could cut about $450-500 off the price of going turbo for some guys.
 

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pimpin since 03!
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Discussion Starter · #6 ·
exactally what im wondering... i mean it seeemss really easy !
 

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nx2thousand said:
What he's talking about is called the MAF hack, a very popular proceedure when turboing the ka24de. The theory is that you take the ratio of your injector size to the inside diameter of your MAF senesor and then replace the maf tube with one that equals the ratio of your new larger injectors.
I am very curious to see if it really works and if anyone has tried it on our sr20's. Could cut about $450-500 off the price of going turbo for some guys.
yeap....this is what im talking about....this guy on the 240 forums posted that it works good for him....so i dont know....got to do more research....
 

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ClamSlut
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Your essentially doing the same thing a s-afc does but minus the resolution. In this case instead of altering the signal after the maf to tell the ecu your at a lower load, your just altering the maf to tell the ecu your at a lower load.

The problem is you may get the fuel right, but now you've moved where you should be on the timing map. What makes it even worse is that your moving in the wrong direction. Buuuuuut that being said if an s-afc works ok, you can probably get this to work ok with enough experimentation. My wild ass guess is idle and part throttle performance probably won't be as good as if you used an s-afc. I wouldn't try running anything larger than 370cc injectors and you might wanna set your base timing a little lower.

Good luck.
 

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pimpin since 03!
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Discussion Starter · #9 ·
thank you calum! i knew it was alot more complicated than just.."hmmm lets get a 2.5 in test pipe and throw the sensor on it lol" i would rather just buy a z32 maf

thanks
jake
 

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Ok....Big breath....

We all have "hotwire" MAFs. What that means is the MAF sensor doesn't actually sense anything. There is an alloy filament (the 'wire') in the MAF that is kept at a fixed temperature (the 'hot') by passing an electric current through it. The filament gets hot due to electrical resistance. The filament is exposed to an air column. As the temperature of the filament drops from exposure the sensor increases voltage to the filament to maintain its temperature (it isn't much different than an incandescent light bulb).

Since only mass can absorb heat, and the filament's temperature is fixed; then simply measuring the volume of air passing over the filament at a given voltage gives a status point. Do this at only 2 points (2 voltages/flows) and you have the ratios you need to determine the flowrate at any given voltage, or visa-versa.

The MAF "sensor" doesn't actually sense anything having to do with flow. The signal we use is actually the drain signal from the heating up of the hotwire.


If you change what proportion of the air column contacts the hotwire you change the flow volume per unit temperature/pressure (thats electrical pressure; ie: volts). So yes, this will work. However, the ratio of injector size to MAF diameter is not what must remain constant. What should remain constant is the ratio of injector size compared to the ratio of hotwire frontal area to MAF port diameter.

Did I just confuse the **** out what should have been simple?
You could wire resistors into the drain line to accomplish the same thing.
 

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pimpin since 03!
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Discussion Starter · #11 ·
iNGEN said:
Ok....Big breath....

We all have "hotwire" MAFs. What that means is the MAF sensor doesn't actually sense anything. There is an alloy filament (the 'wire') in the MAF that is kept at a fixed temperature (the 'hot') by passing an electric current through it. The filament gets hot due to electrical resistance. The filament is exposed to an air column. As the temperature of the filament drops from exposure the sensor increases voltage to the filament to maintain its temperature (it isn't much different than an incandescent light bulb).

Since only mass can absorb heat, and the filament's temperature is fixed; then simply measuring the volume of air passing over the filament at a given voltage gives a status point. Do this at only 2 points (2 voltages/flows) and you have the ratios you need to determine the flowrate at any given voltage, or visa-versa.

The MAF "sensor" doesn't actually sense anything having to do with flow. The signal we use is actually the drain signal from the heating up of the hotwire.


If you change what proportion of the air column contacts the hotwire you change the flow volume per unit temperature/pressure (thats electrical pressure; ie: volts). So yes, this will work. However, the ratio of injector size to MAF diameter is not what must remain constant. What should remain constant is the ratio of injector size compared to the ratio of hotwire frontal area to MAF port diameter.

Did I just confuse the **** out what should have been simple?
You could wire resistors into the drain line to accomplish the same thing.

lol seriously all i can say is WTF... i get it totally but i dont how or what way i would go about performing this procedure
 

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pimpin since 03!
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Discussion Starter · #12 ·
it went from taking the sensor off and putting it into a new pipe. all the way to resistors and injector size comparison and all sorts of crap!

z32 here i come
 
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