afm screw

[black89t]

for those that adjust them do you have any problems with the screw backing out once adjusted from the stock position? or does it stay in place without any locktite or lock nut?

there doesn't seem to be any info about that.

 

[isnms]

Mine has not backed out. It is all the way in, stock screw, and I still have the bottom support brace for the afm. No loctite at this time. I don't know what would happen if your setting is somewhere in the middle or all the way out.

 

[WhtMa71]

I have mine turned about halfway out..It's still there.

 

[ForcedTorque]

How much is to be gained with the almighty screw? I've never read anything to justify all the headache I have read about it.

 

[jetjock]

Shouldn't back out...has an O ring to keep it snug. Adjustment effect depends on whether it's a turbo or N/A afm since the screw serves different purposes on each. It's why the factory position of one is code stamped into the housing while the other isn't...

 

[WhtMa71]

How much is to be gained with the almighty screw? I've never read anything to justify all the headache I have read about it.

I have mine backed out a bit to keep from getting fuel cut as easily.

I have boost set at about 10psi with my Dr Jones BC but it sometimes tends to creep up on long pulls and i'll hit fuel cut. It also liked to hit fuel cut during very fast, near redline shifts from 1st-2nd. Right when I slammed on the gas in 2nd BAM-fuel cut.

Backing the screw out helped a lot and it doesn't do this anymore.

 

[black89t]

thanks for the replies.

 

[Mario]

I have mine backed out a bit to keep from getting fuel cut as easily.

I have boost set at about 10psi with my Dr Jones BC but it sometimes tends to creep up on long pulls and i'll hit fuel cut. It also liked to hit fuel cut during very fast, near redline shifts from 1st-2nd. Right when I slammed on the gas in 2nd BAM-fuel cut.

Backing the screw out helped a lot and it doesn't do this anymore.

same for me

 

[dumbo]

So WHAT does it do, and what is the purpose of the screw.

 

[WhtMa71]

The screw allows unmetered air through the AFM so it kind of "tricks" the AFM into letting you run more boost without hitting fuel cut.

 

[Piratetip]

Only if you match the injectors.

 

[7MGTEsup]

For all those who worry about backing the screw out I had mine backed all the way out (about 1 turn in) and my a/f's were still very safe at around 11 - 11.4:1 at full boost and I was able to run upto 14psi before the ECU said no more fun. Looking through the AFM I would say its only about 7-10% of the size of the main passage.

 

[dumbo]

hmm wish I had a afm to check it out, thanks. map based