Z31 MAF???

[uncle_louie83]

hey i know alot of people here like using the z32 maf. But i see alot of z31 mafs at the junkyard...these babies are good for 350hp and i figured since im starting at 300hp then why not?. But to my worry is will it work? im sure i can get it to wire up fine. BUT i have an apexi safc...which in and out settings would i use. I use 1in and 1out for my stock maf as of right now...so i need some insight to this. anyone wanna chime in?

lewis

p.s. the turbo and non turbo maf sensors are the same part numbers...looked it up...but i think the 88 and 89 mafs would work better than 87 and below due to the era of electronics.

[Bernard]

A z31 maf is not good for 350hp in stock condition. With 12vdc connected they will output 1.6vdc without the engine running. It will not work properly with any ecu other than a stock z31 ecu. You can install a resistor to bring down the voltage to what your ecu likes to see if you want to use one. The 89-94 Maxima is good to 350hp and has a normal voltage output that will work on your ecu.

Bernard

[uncle_louie83]

the v6 or 4 cylinder model? cause i can get a maxima maf easy.

lewis

[Bernard]

89-94 model, and they're all 6 cylinder.

[DRIFTEADOR]

A z31 maf is not good for 350hp in stock condition. With 12vdc connected they will output 1.6vdc without the engine running. It will not work properly with any ecu other than a stock z31 ecu.

thats what the safc is forQuote »You can install a resistor to bring down the voltage to what your ecu likes to see if you want to use one. The 89-94 Maxima is good to 350hp and has a normal voltage output that will work on your ecu.

Bernard[/quote]you may be right, i dont know, but it doesnt make sense to me why the voltage output would be the same, but is still able to support more hp. usually you give up resolution for a wider range of airflow readings, assuming max voltage is the same. are you saying the maxima maf reads a higher max voltage than other nissan mafs (5v max, I believe)?

[Bernard]

The z31 will read 5.12 vdc before you reach 300hp. I know this from experience. The maf will read more air, as will many mafs. The cobra maf will read up to 6vdc, so will the z31 maf. With a resister to drop the voltage output from the z31 maf down to about 1.2vdc at idle, the maf will max out around 350hp. JWT used to sell a control system like this for vg30/L28's. I don't know how high the max maf voltage will go, but at 5.12vdc it's good to 350hp (crank hp)

Bernard

[uncle_louie83]

im looking for more of 350 whp...not crank hp...

lewis

[DRIFTEADOR]

im having a hard time understanding how a resistor on the maf out wire would allow for more hp. if anything it would meter a smaller range. a resistor not only lowers output voltage at idle, it lowers the output everywhere. if the z31 mafs metered up to 300hp @ 5.12v before, with a resistor it would meter the same 300hp only at a lower voltage. how does a resistor after the mafs affect how much cooling of the wires a mafs can meter?

another thing, anyone know what 240 maf sensors output with the engine off? I would've guessed mafs rated for lower hp would output higher voltage numbers at the same flow as the higher rated maf sensor. but the z31's 1.6v w/ engine off already sounds pretty high.

[Bernard]

You're lowering the voltage for the ecu's benefit, not the maf's. The ecu can't read more than 5.12vdc. I've had my z31 maf up to 5.79vdc. I have flow tests from the cobra maf up to 6vdc as well. So you trim the output to the ecu by 1volt and now the ecu is seeing 4.79vdc while the maf is still putting out 5.79vdc.

[uncle_louie83]

so i "could" use the z31 maf for my car as long as i used an inline resistor. cause i have a ton of resistors. i need a 1v drop resistor right? cause if so i have one in my hand now that is new. I looked up the part numbers for the N/A and turbo models....the part numbers are the same. So i could use the N/A version too i guess. The junkyard is full of z31's...ill go get one this week sometime unless i see an old school maxima.

lewis

[Bernard]

yes, you need to use a potentiometer. connect one side to the maf voltage in, the other side to ground and the middle leg to the ecu. adjust it to the voltage you want. is there an rb20det maf in and out on the safc? it has the same curve as the z31.Bernard