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Old Mar 21, 2023 | 05:13 PM
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AIS flow mods

I know there are many posts about this but most I could find are years old.
question for those who have done the mods for improved airflow do you regret any of them? "Zoodad" ,"secret zoodad", fender hole. Other I have not seen?

Since removing the garbage k&n/stock air box I have had lower power, and smoke (not much, I have just lived with it.). Also I think it is sucking some oil out of the crank case under high boost.

Just wanted to ask you all before I go cutting holes.

Thanks
 
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Old Mar 21, 2023 | 06:03 PM
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What did you put back in to replace the stock air filter assembly?
 
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Old Mar 21, 2023 | 06:05 PM
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The ford ais severe duty intake with the blue filter.
 
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Old Mar 21, 2023 | 06:10 PM
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Those are supposed to utilize the intake duct built into the fender well. No need for zoodad. I tried one of those years ago and pulled the filter minder to the first notch with a brand new filter element installed going over Snoqualmie pass while pulling the 5th wheel. It came back out a short time later and the trusty old 6637 filter went back in. Ended up selling it to a friend with a 7.3.
 
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Old Mar 21, 2023 | 06:41 PM
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The filter is the restriction, not the box.
 
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Old Mar 21, 2023 | 06:51 PM
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Yeah, that's why mine came right back out. I have 4.88 rear axle, engine sings a merry tune while underway and it needs a lot more air than the average pickup truck.
 
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Old Mar 21, 2023 | 08:48 PM
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Originally Posted by Kwikkordead
Those are supposed to utilize the intake duct built into the fender well. No need for zoodad. I tried one of those years ago and pulled the filter minder to the first notch with a brand new filter element installed going over Snoqualmie pass while pulling the 5th wheel. It came back out a short time later and the trusty old 6637 filter went back in. Ended up selling it to a friend with a 7.3.
No sir. The AIS pulls air from the front through a snorkel similar but larger than stock.

Originally Posted by Dan V
The filter is the restriction, not the box.
Not completely true. I performed testing. The box itself is a restriction which was helped by cutting a fender sleeve hole.

AIS Testing Thread





The filter minder can pull in on hard pulls in a hot tune but on normal driving it rarely goes past the first notch. This includes medium towing. I decided to sacrifice a little flow in the name of a quiet intake.

I performed the Secret Zoodad and highly recommend it. It’s completely invisible, no chance of rain/bug intrusion, it’s a straight shot to the snorkel, and should work based off the pressure principle at the front of the truck. I would not do the regular Zoodad personally.
 
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Old Mar 21, 2023 | 08:55 PM
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IIRC some folks have made holes in the bottom of the box which have resulted in less restriction. That plus @RacinJasonWV data imply to me that the box is a big contributor to restriction vs the filter. It makes sense since Powercore filters are designed around air being ingested "from the front" vs radially. In the 7.3 the air has to "turn right then upwards" to enter the powercore filter, then upon exit has to make another 90 degree bend.
 
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Old Mar 21, 2023 | 10:34 PM
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Originally Posted by RacinJasonWV
No sir. The AIS pulls air from the front through a snorkel similar but larger than stock.
Thank you. It's been more than ten years ago now, so details get a little blurred.
 
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Old Mar 22, 2023 | 08:08 AM
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Thank you everyone for your input.
what I am hearing is secret zoodad, fender hole / sleeve. If that doesn't work then 6637.
​​​​​​If I end up going the 6637 would the kit at riffraff with the blue filter be a good option?
 
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Old Mar 22, 2023 | 08:13 AM
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Originally Posted by S-squatch
Thank you everyone for your input.
what I am hearing is secret zoodad, fender hole / sleeve. If that doesn't work then 6637.
​​​​​​If I end up going the 6637 would the kit at riffraff with the blue filter be a good option?
Yes, it would. One of the best around.
 
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