2g maf on 1g questions

[terminaltsi]

ok, so here's the scenario. with my 1g maf and 650 injectors, i have my afc at -35 on hi settings...thereby putting me on a different timing map (low airflow, high timing)than it should be for the amount of air that is actually flowing...causing knock and high egt's. if i give some fuel back, it becomes too rich and stutters.
from what i've read, a 2g maf on a 1g causes the ecu to run about 29% leaner than a 1g maf. if this is true, would i then be able to pull only 6% out on the afc, putting the ecu in the proper timing map for the actual airflow? or would the 2g maf simply act like the afc, "fooling" the ecu and still making it use the low airflow timing map? if that' sthe case, then it wouldn't really be helping my problem.

 

[defrag010]

I don't know about 680cc injectors....

but I have a friend who had a 2g maf with stock injectors and an afc. he said that it was tough to get tuned good but when he put 550cc injectors on he said that he zero'd out the afc and the car ran like stock (2g maf and 550's)

 

[terminaltsi]

so basically since 550's are about 20% bigger than stock, the 2g maf pulled 20% airflow...sounds like it works kind of like an afc...
then my big question is, to anyone who knows, does it just fool the ecu to do this?

 

[q92awd]

You're correct in your assumption that it works like an afc. The ecu "sees" less air with the 2g mas when it's installed on a 1g so it's like having a afc that's locked at a certain percent (appox. -20%). It's usually a decent match with 550cc inj. and some people use that combo w/out an afc at all.
You could order a new chip or hack the mas if you want to try to keep it from reading so far from stock airflow.

 

[terminaltsi]

after more in depth research, i've decided to go with a chip to solve my problems. more cost, but more benefits and it will be more "right" for the car.