Quote:
Originally Posted by Brad Roberts
I do tune the cars that I have used this setup in, but I also believe that the stock ECU (no flash or tune) can easily adapt for this and headers.
This really is only slightly different from installing a cone filter setup.
Thoughts?
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I have doubts. The DME uses the MAF to measure air speed. It needs to convert that speed to volume flow so it knows how much air the engine is injesting. The conversion calculation has to include the diameter of the MAF housing.
Increase the MAF housing without telling the DME and it thinks the airflow is lower than it really is. Same speed + larger area = more flow. And not a little difference, it's a 23% increase in area! Huge! I would be really surprised if there was some way the DME can compensate to that change.
It means Porsche would have had to allow for housing changes while programming and then figure out a way to double check the sensor. I don't see a system that can make the correction. You know how slow O2 sensors are, they aren't fast enough to make a meaningful correction. They are mostly used for steady state (cruising) corrections. And there is no MAP sensor to verify flow with a pressure measurement.
I bet when you do a tune, the car is running very lean to start, yes?