MAF orientation

[kj217]

i have accidentally rotated my custom intake pipe few degrees down from the hood,, all fuel trims and idle readings changed dramatically,, the car went lean but idle became super smooth,,

i can't understand how intake/maf geometrical orientation impacts airflow?
and if it actually counts,, what is the best way to position intake pipe and maf?

[ttz06vette]

Few degrees shouldn't matter but significant orientation changes could change the way air is presented to the MAF.

[DSteck]

If there's a bend near the MAF (within three diameters as a rule of thumb), then orientation certainly impacts the calibration curve.

[edcmat-l1]

Airflow is never evenly distributed within a tube. Never ever ever. It always wants to flow on one side or the other, or top or bottom. Take a port in an intake manifold for instance, the airflow will hug the roof of the port in most cases.

[kj217]

if i kept the MAF exactly in place,, what is the impact of extending the pipe for the filter to go all the way down to fog lamp area for colder air?

i can't have the difference between IAT and ambient lower than 35F degrees,,

[kj217]

20130501_015545.jpg20130501_015601.jpg

[kj217]

i have extended the intake pipe down to fog light opening,, IAT is only 7c deg higher than ambient but,, fueling is off,, needed to increase PE to maintain afr @ 11:1,, also spark advance histogram didn't read anything south 1.32 g/sec,, when the intake was short used to pass 1.36,,

please,, share your thoughts,,

[Ben Charles]

Fix the MAF for Fueling not just the PE table, I'd run that setup high 11's AFR for more power and tq. The Spark tables are in g/cyl not g/sec, and with that setup I would bet you should be maxing the 1.36 G/CYL limit. You can probably fix the axis on that table to read more though.

As far as the MAF, what the other guys said. I personally had a Procharged setup with the MAF right after a 90 degree bend, couldn't tune around it till I moved the MAF further downstream into a straight in/out section.

[kj217]

Fix the MAF for Fueling not just the PE table, I'd run that setup high 11's AFR for more power and tq. The Spark tables are in g/cyl not g/sec, and with that setup I would bet you should be maxing the 1.36 G/CYL limit. You can probably fix the axis on that table to read more though.

As far as the MAF, what the other guys said. I personally had a Procharged setup with the MAF right after a 90 degree bend, couldn't tune around it till I moved the MAF further downstream into a straight in/out section.

i adjusted PE a temporary work around to test potential impact of extending the intake pipe,, as i said MAF fueling is off,, but i can't see why -with long intake- reading don't even reach 1.36 g/cyl,,
with the short intake the car runs better and healthier but IAT stays up around 125F,,

how can i fix the x-axis in both histogram and main spark tables in tune file?