RomRaider

The 2.2k resistor is based on MRFs testing where he found a 2.2k resistor dropped the voltage from 1v to 0.8v.
The resistor gets put in series (inline) on the yellow MAF signal wire.

Its completely theoretical from my perspective at this point in time as my engine bay still looks like this:

Well, that's a good looking engine bay!

Busterhax, do you feel that multiplying the values in the MAF table by 1.22 basically adheres to the third order polynomial nature of these things (not being a mathemagician, I have no real idea of how a third order polynomial works haha)? I'm not opposed to doing some testing on this, and in a perfect world, if we got the rescale values just right, no actual retuning would be necessary, right?

MRF mentioned a while ago that one way to test this stuff would be to set up two MAFs in series, and blow through them with a leaf blower. I can see how it might be useful to setup a rig like that and at least make sure the output voltages followed a basic relationship like that, or if not, figure out what a more exact relationship might be. I have a commercial style leaf blower, so I could test it out.

Alternatively, I could set it up with a single MAF so I can just set the throttle at a certain spot, and then pop a resistor on and off of the signal wire for measurements at the given air flow...

unfortunately it will never be a precise art. There are variances from one MAF to another that will never enable a MAF curve to be perfect for everyone. If i were to put both MAFs in series and log the voltage, it probably wouldnt be the same for your car.

That's why these curves are for getting in the ballpark only and must be revised in the real world for your specific hardware.

Unfortunately it isn't a perfect world and you can assume no MAF transfer curves are 100% perfect therefore a retune will always be necessary with any MAF change.

If you're multiplying the whole table by a single value, the curve stays the same. I believe using resistors is the cheap, crappy way out but a good rule of thumb to get things working is every 1k of resistance, add 10%.

So 1k resistor = multiply value by 1.1 (adds 10%)
So 2k resistor = multiply factory value by 1.2 (adds 20%)
So 2.2k resistor = multiply factory value by 1.22 (adds 22%)

Again, there are plenty of cheapy slot style MAFs out there and we are more than capable of changing the MAF table so I would avoid using resistors.

Thanks for the resistor info.

I have a spare M62b44 540i MAF, but I never see anyone saying they have a good MAF table for those. Do you know of any?

Assuming not, what is your preferred option for a budget friendly MAF that flows a good amount and for which we know an actual set of values?

Nissan z33 (350z, 370z, maxima etc) slot style MAF is like $20 and the curve is known. It seems to be pretty much the same as the ford slot style maf for which we also know the curve.

Pic up a 3" tube from ebay with the flange welded on for like $80 and you have a relatively budget and (more) modern maf setup.

I'm down for testing that out if we on here haven't tested it yet. I have plenty of 3" aluminum tube, and a tig welder. What flange is needed for those MAFs if you have any links handy? I'll grab one and try it.

Something like this:

http://www.ebay.com/itm/3-0-OD-Slot-Sty ... MI&vxp=mtr

What actual sensor do you like, as an example?

22680-7S00 is the part number for the nissan maf.
http://www.ebay.com/itm/MAF-Mass-Air-Flow-Sensor-Meter-for-Nissan-Infiniti-Altima-Murano-G37-22680-7S000-/160999304361?fits=Make%3ANissan&hash=item257c4e6ca9:g:ne0AAOxyoA1RWB9w&vxp=mtr

Maf flange:
http://www.ebay.com/itm/MAF-Mass-Air-Flow-Sensor-Bung-LS-Billet-Boss-Mount-Weld-Flange-LS-LS3-LS7-VW-55-/131998974445?hash=item1ebbc081ed:g:WK4AAOSwjXRXaPl-&vxp=mtr

Alright, cool, that will be fun! Can you help me out with translation of the wiring? We'll have an unused pin, right?

You'll have chassis and signal grounds from the stock harness, and only the one signal ground on the MAF.

I just connected both engine harness grounds to the single MAF signal ground on the MAF.

After thinking about this some more, I have concluded that the first thing I need to do is play around with a resistor and see how well I can nail down the tune with that. It's just too simple (in terms of the install), too cheap, and overall too RomRaider not to at least experience before I move onto a different MAF or whatever.

I'd still like to test out some speed density code though. That would be the bomb in a lot of ways. I don't see any reason why the MAF based tune can't work fine for a turbo setup though (theoretically). And there are at least a couple of guys on here who do seem to be having success with it. I think it's probably just important to maintain a bit more margin from the detonation threshold than if the tune is based directly on MAP.

Is anyone currently running the Nissan MAF?

I am

Sweet! How well is it working with the published transfer curve? My turbo project is commencing in a couple of days, and I was planning to just run with a resistor, but I could go for one of these MAFs if the scaling curve is more accurate.

I'm still in the early tuning stages, but I can confirm that at idle, my STFT only drifts between -3% and 3%.

I'm running a 2.2k resistor with mine.