Tuned my GT and having problem with MAF sensor


DXB.GT

GT Owner
Aug 17, 2017
17
OP - Let me explain further. Like many sensors throughout most modern cars, they are designed to give a a "signal" back to the ECU and most of these sensors are designed to provide a signal of 0v - 5v. In the case of the MAF, the sensor is designed for a particular position and air flow in a given car. The OEM attempts to maximize the full range of the sensor in order to have the most fidelity. So, let's say at idle, the MAF is at 0.5v. As the air volume to the engine increases (as detected by the MAF), the voltage starts to rise.... so, say at 1/2 load, the MAF may be around 2.5 volts and a full, maximum (OEM) air flow it is at 4.8v.

The problem arises when you make modifications to the GT and increase its airflow capacity. You have done this with more boost, and an improved exhaust system. As such, the airflow may be improved such that the MAF value goes to 5.1v!!! In the case when the ECU sees a value out of range (0-5v) from one of its sensors, it is usually programmed to go into limp mode. This is logical, if you think about it.... if the ECU has a sensor that it is dependent upon to safely operate the engine and that sensor has provided bad input, it can no longer be relied upon.

So, what this scaling devices do is that they plug into the MAF, and they scale down the MAF voltage readings back to the ECU. When these devices are in place, the tuner MUST re-program the vehicle to account for their presence. In our little scenario above, at 1/2 load, the OEM MAF value may be 2.5v but with the scaler in place, it may be 2.3v. The important part however, is that the MAF may yield a 5.1v at full load, but the scaler would report back a 4.9v to the ECU.... and everyone is happy.

Just a note about aftermarket intakes: The fact that a different intake may require a different MAF or the inclusion of a scaler on the OEM MAF DOES NOT (necessarily) mean that the intake is flowing more air. MAFs are calibrated to be in a particular position in the intake track where they can "see" a linear and reliable progression of air flow as demanded by the engine. Simply MOVING the OEM MAF in an otherwise stock intake track will require re-calibration and maybe even a scaler..... having nothing to do with genuinely increased airflow.

OP - if you want to post or PM me dyno pulls, that's great. The dyno file itself would be most telling - but minimally we need to see a plot with A/F ratios across the RPM range.

Thanks bro for the good explanation, now it became clear to me how does the MAFia chip works.

Btw, few days back I received the MAFia chip and I got it fixed on my car. As I told u before, the car got custom tuned by LUND RACING through STC (Remotely). I put my car on dyno yesterday, I can say that I'm happy with the results and they was fare for me.
Keeping in mind the following
- I mentioned the modes above.
-weather was not cold (the temp was around 30 C = 88 f degree) at midnight
- the intake got squeezed (see the pictures)

Results Using Dyno Jet
627 rwhp
593 rwtq
IMG_9762.jpg

And here are some pics shows the intake squeezes while running the car, i will buy the intake support

IMG_9766.jpg
IMG_9767.jpg

I don't have the dayo file right now but, i wil try to provid it soon

Thanks a lot







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