MAF Flow rates

Can anybody tell me what normal maf flow rates are for a stock 1.5T ?Or even tuned one?
I'm using the Torque Pro app and finally got the MAF Flow rate working .I did a log and i saw Max flow rate of about 152g/s in WOT.Does this sound about right ?

Hondanickx said:

Can anybody tell me what normal maf flow rates are for a stock 1.5T ?Or even tuned one?
I'm using the Torque Pro app and finally got the MAF Flow rate working .I did a log and i saw Max flow rate of about 152g/s in WOT.Does this sound about right ?

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I have a Torque Pro too and am interested in how you got yours to work properly. I'll let you know what mine is tonight if I get it to show on my Pro.

I also saw in a Jaguar forum that you can calculate Maf g/s to horsepower by using the following formula --->
Maf g/s * 1.25. This would make 152g/s the equivalent to 190hp (engine). Take this with a grain of salt.

Myx said:

I have a Torque Pro too and am interested in how you got yours to work properly. I'll let you know what mine is tonight if I get it to show on my Pro.

I also saw in a Jaguar forum that you can calculate Maf g/s to horsepower by using the following formula --->
Maf g/s * 1.25. This would make 152g/s the equivalent to 190hp (engine). Take this with a grain of salt.

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190hp sounds about right for a stock car.Thanks!

Here is everything i entered in torque which you can enter as a custom pid in torque pro:

I got working LTFT , STFT, MAF airflow, ECT, Vacuum/boost,IAT ,IAT2. The MAF equatation i got solved because of 2 guys on the Torque bhp forum .So all credits go to them.

OBD2 Mode /PID = 0166
Long name = Maf air flow rate
Short name = MAF
Min value = 0
Max value= 655.35
Unit type= g/s
Equatation= ((256*B)+C)*0.03125


OBD2 Mode /PID = 0117
Long name = Long Term Fuel Trim
Short name = LTFT
Min value = -100
Max value= 99.22
Unit type= %
Equatation= (A-128)*100/128

OBD2 Mode /PID = 0116
Long name = Short Term Fuel Trim
Short name = STFT
Min value = -100
Max value= 99.22
Unit type= %
Equatation= (A-128)*100/128

OBD2 Mode /PID = 0167
Long name = Engine Coolant Temp
Short name = ECT
Min value = -40
Max value= 300
Unit type= °C
Equatation= B-40


OBD2 Mode /PID = 0168
Long name = Intake Air Temp
Short name = IAT
Min value = -40
Max value= 300
Unit type= °C
Equatation= B-40

OBD2 Mode /PID = 0168
Long name = Intake Air Temp 2
Short name = IAT2
Min value = -40
Max value= 300
Unit type= °C
Equatation= C-40


To get the Boost to display properly follow @LakeEffect advice .This worked for me and showed 14-15PSI ,before i only got 7-8psi.
"I had the same behavior with the Turbo Boost gauge in Torque Pro, so I changed the Boost Calculation Method under "Settings", "OBD2 Adapter Settings", "Boost calculation method". I changed it from "Prefer MAP(Default)" to "Prefer ALT". The vacuum numbers didn't change, but my boost at WOT started reading 14-16 (depending on conditions). Hope that helps."

Just got back from testing. 165g/s Yeah, I know my car don't take in much air. Mods are in my sig.

Nice results ,so it works with you as Well?
I changed the gauge into one that shows the min and max values and did another WOT pull up to Rev limiter.(This time in 2nd gear)Now i got a max of 164g/s At 16psi.
Don't know how this works exactly but a tuned engine draws more hp out of the same volume of air?

Or does the maf sensor also takes in the air temp to calculate the air flow?

Did some more testing with the prl stage 1 kit .MAF flow rate stayed the same as before.I did noticed a change in LTFT after i installed the silicone hose.It went from -6 ~ -7 to -6 ~ -5.The filter itself didn't change anything.
Does the MAF flow rate ever change ?
Afaik the MAP sensor is based on the the MAF.If the filter does more g/s, you need less boost for the same air mass.
so the map decreases the boost to have the same air mass ... right?

The actual sensor (MAF sensor) produces a value in Volts (0-5volts). There is a map in the ECU (MAF scaling in KTuner / Hondata) that calculates the actual flow rate (in g/s) so the MAF flow rate is a calculated value.
At the same boost level, the MAF voltage will vary depending on external temperatures, and so will the flow rate.
From the factory, the MAF scale reads more flow than actual as the flow increases (higher rpm / boost levels) and one can see that by the amount of LTFT/STFT (for USDM in closed loop WOT) or the difference of Target vs Actual AFR (for EUDM in open loop WOT).
With a calibrated MAF, the max reading with the factory boost curve should be ~ 140g/s at 4.5v at 35C IAT
With the KTuner Starter21 and a calibrated MAF, the max reading should be ~160-165g/s at 4.7v and available briefly
My custom tune that keeps ~220whp from 5000-6500rpm, pushes 150-155g/s (4.6-4.65v) in that rpm range at 40C IAT on the Dyno and 165-170g/s (4.7-4.8v) at 20C IAT in a cool winter evening on the street.
I run a Mishimoto Air Intake.

As you lean the car out via maf scaling adjustments this number is directly what your changing. Its not as much as the number itself as it is the combination of the tuning. 11.4 afr on the top end will result in a lower maf output number when compared to 10.8 etc. Its all relative based on your other changes. If the computer is adjusted to run any sort of leaner target mixture it is generally going to report less airflow or similar airflow as before the change.

165g/s at 9.8-10.1 afr will have lower power output as a different car registering 165g/s that is at 11.8 afr. Same reported airflow number with much different results.

The screenshot above is from my map and shows similar maf readings as what you guys are discussing but look at the boost/timing/afr---thats where the money is.

I could take this same tune and increase the maf output number on purpose and it would be in the mid 170g/s range but it would be running afr in the 10-9.8 range. Would make it report more "power" via a higher airflow number in the data but would surely be making less power than before.

Sorry I keep thinking of more stuff to add....the other consideration is the amount of egr% the car is running at the time. Higher the egr%, the more the aircharge is being diluted for emmissions purposes as more exhaust is making its way back into the cylinder. Cam/valve timing phasing also.

Lots of factors....

The next step in your mental process down this path is to realize you can pay attention to the amount of fuel the car is utilizing rather than reported airflow via injector duty cycle.....at least on non direct injected cars this is a decent way to know what gains you may or may not have found. The problem with this as well is the sheer "size" of our injectors along with the variances in high pressure pump output. Again you run into the problem of 1% increase in number could be nothing or it could be 20 more horsepower because the variability in the change of "just that 1%" could be rather large.

Hope this makes sense.

PowerPerLiter said:

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Since we are sharing, this is a log I did a few days ago testing some Boostane Octane booster. I picked 68mph (Same as Power above), so you can gauge what my car is up too.

Myx said:

Since we are sharing, this is a log I did a few days ago testing some Boostane Octane booster. I picked 68mph (Same as Power above), so you can gauge what my car is up too.

Click to expand...

Why do you think you weren't hitting your boost target? Or was that screen taken just before hitting the target?

Dam Myx that thing is cookin!

Strange when comparing the afm.c (in my pic) to the Mg/stk of yours. That is the reported airflow per stroke of the piston. Weird to see your maf g/s be that much higher without a corresponding higher number of "cylinder fill".

Just kinda proves my point that the data doesnt always reflect expected power output with these cars.