Z32 maf voltage

**Coheed** · 09-13-09, 11:54 PM

This is for future reference. If you have any contribution please add. Tell us how much power you put down (dyno type) and your Z32 peak maf voltage when that WHP was reached.

On the dynojet I hit 4.52V peak and made about 361whp corrected.

The dynomite yesterday, I had 4.77V peak and put down 379.9whp.

Please add to this what info you can. Thanks.

**OnTheChip** · 09-14-09, 11:11 AM

What RPM did the MAF voltage peaks occur?

**Coheed** · 09-15-09, 12:41 AM

7200rpm.

Peak power was at 7200rpm. Injector duty (740cc) was 83%.

**Coheed** · 09-15-09, 12:43 AM

I am pretty sure that around 4V on the maf you should be around 300whp. 4.5V should be around 350-375whp. 4.7V is around the 400whp mark?

**gtswrx** · 09-15-09, 02:14 AM

Not so easy to ballpark the voltages as they are not linear.

Someone good in math could calculate the curve of the voltages and make up a respective curve in WHPs??? (Not so easy or accurate as we would want)

**Coheed** · 09-15-09, 01:40 PM

Ya, I understand that. The maf voltage is sorta exponential. So I just want to get a sort of idea on where it would be ballpark.

You can already see the voltage isn't linear when 360whp is 4.5V and 400 is around 4.7V.

**OnTheChip** · 09-15-09, 03:18 PM

Using the values from the MAF VQ table for A Z32 MAF:
4.00V = 31689
4.52V = 47156
4.77V = 56223

**Coheed** · 09-16-09, 03:10 AM

^^^ What is that? Please explain.

**OnTheChip** · 09-16-09, 11:37 AM

Those are the MAF voltage to Q (mass flow rate) numbers from the VQ table used to calculate TP. You are correct that the VQ table is non-linear, and different MAF sensors output different voltages at the same mass air flow rate, so the Q numbers would be better to use for your HP prediction, rather than voltage.

Dave

**Coheed** · 09-16-09, 09:32 PM

So what unit are these Q numbers in? And ho can you calculate flow rate to hp? Any ideas? It would be cool if we could relate the mass flow numbers to some sort of HP prediction. Even if it had a accuracy within 15% it would still be a really cool tuning tool. Small adjustments would show up as a change in flow rate...

**OnTheChip** · 09-16-09, 09:57 PM

Originally Posted by Coheed

So what unit are these Q numbers in? And ho can you calculate flow rate to hp? Any ideas? It would be cool if we could relate the mass flow numbers to some sort of HP prediction. Even if it had a accuracy within 15% it would still be a really cool tuning tool. Small adjustments would show up as a change in flow rate...

Q values represent relative mass flow rate and are unit-less. Take a look at this page for HP vs mass flow rate info: Technical Database - Engine
although I don't claim to know that it is correct.

**jp314** · 04-06-10, 07:18 PM

Bringing back an bit of an old thread - was searching for something
else, found this, decided to add a data point...

4.05v peak MAF on DynoDynamics (with Dynojet correction factor)
= 246whp - 50 lb MSD peak = 71.7%

Same car, different turbo, intake, exhaust, NOT on dyno:
4.25v peak MAF ???whp - 50lb MSD peak = 80%
4.309v peak MAF ???whp - 50lb MSD peak = 85%
4.49v peak MAF ???whp - 50lb MSD peak = 95%

Interpolating the Z32 VQMAP, based on 5.12v = 500whp,
and percentages of airflow:
4.05v = 238.2hp *pretty close to 246whp dyno above
4.52v = 335.6hp
4.77v = 398.2hp

Originally Posted by dfddfd2

Using the values from the MAF VQ table for A Z32 MAF:
4.00V = 31689
4.52V = 47156
4.77V = 56223

The table I found for the Z32 VG30DETT MAF shows:
4.00V = 30042
4.48V = 42772
4.56V = 45232
4.72V = 50466
4.80V = 53247
Not saying either one is right or wrong - not sure why there's a discrepancy?

**beto** · 04-06-10, 09:06 PM

Coheed, how much boost were you running at the time?
this is good info for me since Im going to use a maf voltage activated meth injection, but since I will tune on the street using wideband I dont know the whp, but Im going to need the maf voltage vs boost so the meth will activate at certain psi vs voltage, or at least close to it...

**LikeTheMovies** · 04-06-10, 10:14 PM

I get about 4.15v with 520's at 75%

**jp314** · 04-07-10, 03:38 PM

Originally Posted by LikeTheMovies

I get about 4.15v with 520's at 75%

That is right in line with the data points I posted above.
The interpolating from the spreadsheet I have says 256.9hp for 4.15v.
Same setup as your sig - 252hp? If so, the spreadsheet is pretty close.

**supercowboy** · 04-07-10, 10:48 PM

you can change value points on the maf scale. voltage to q value. can actually make the car read more air to a certain extent

**Daniel 100NX** · 09-03-10, 04:33 PM

Here you go guys..

Found this loooong time ago on a forum. Dont know how accurate it is, but you got the picture.
But remember flow doesnt have to cope with your whp output since factors as A/F, cilinderpressure, wheels, pullies etc. are all part of the game to your final whp output.

Im running a 2871 0.86 .56 trim at 1.3 bar and get 4.53V and 71% on 740's.
Coheed runs 83% on 740's at 380whp so that makes mine at 325whp. 4.53V reads 330ish whp, so that should be about right I reckon (this is RWD sr20 S13 that is..).

**OnTheChip** · 09-03-10, 05:10 PM

Do you know what the numbers in each column represent?

**Daniel 100NX** · 09-03-10, 05:17 PM

? - Voltage - ? - Percentage of capacity - Whp output

Obviously... but its not mine.

**UNISA JECS** · 09-03-10, 05:39 PM

Z32 MAF VQ TABLE

**gomba** · 05-01-12, 02:11 PM

I'm not sure how accurate that table is. I was around 4.28V making about 315whp...I think whatever calculations were used should be moved up on scale to fit with what people were seeing here.

-G

**dave_f** · 05-01-12, 07:13 PM

I think a lot of the variation has a lot to do with how the MAF sensors are installed in each individual set-up. I suspect that myN62 is over-reporting voltage... not sure if it’s a bad sensor, or if it’s the proximity and orientation of the MAF to the turbo inlet.
-dave

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