Quote:
Originally Posted by MaximeT
I will add that if you run a device that increase airflow without a tune, AFR will get too lean and damage the engine.
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the ecu will detect a difference in measured afr (by 02 sensor) and commanded afr (what the ECU is asking for) in closed loop operation and alter the LTFT compensation to bring these values closer together. while compensations may not be ideal they will then be applied in open loop operation to correct afr differences.
your more likely to run into issues changing an intake than changing header.
you not going to get much advantage from header unless you alter intake and exhaust cam timing to take advantage of the different flow characteristics of the header and lack of catylitic converter.
The stock tune runs very rich afr targeting (commanded AFR) of about 10.7 afr at higher rpm unlikely your going to get it to run lean enough to do damage on stock tune by running a header alone. Leaning it out a bit gives more power.
most tuner target about 11.5 to 12.5 on petrol NA