Air intake
Laughing Gas
Joined: Oct 2009
Posts: 831
Likes: 2
From: Vacaville, CA
What other mods do you have done? exhaust, turbo, injectors, tuner, etc? As far as air flow goes, you should be doing just fine with the 6637. The AIS is nice, but pricey and I don't think you will see any benefit to an Airaid, Volant, AFE, etc over the 6637.
Cargo Master
Joined: Oct 2008
Posts: 3,330
Likes: 13
From: Eaton, CO
Is this a system you bought from Ford? I've had enough of the 6637 and quite frankly, regret butchering my OEM setup to install this POS.
i ain't rite
Joined: Mar 2005
Posts: 65,422
Likes: 5,507
From: Marlboro Mental Hospital.
the 6637 is a full flow filter with a 4 inch outlet. the turbo has a 4 inch inlet.
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you can't fix stupid!
Joined: Mar 2008
Posts: 1,906
Likes: 2
dont think so......
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Veteran/Sheepdog
Joined: Feb 2012
Posts: 6,047
Likes: 110
From: Western AR
Yes, Ford designed it for these trucks. You can get them from the site sponsors on here, or you can go to Dieselfiltersonline.com and get it for $190. High flow and super high filtration. I am with Tugly...I love mine, too.
Hotshot
Joined: Jan 2011
Posts: 18,849
Likes: 179
From: Puget Sound
I never - ever heard my turbo from under the hood until I got a 38R. Even then, it only happens when I goose it and it is so faint that my wife will say "I think I can hear the turbo". If the radio is on... gone!
Posting Guru
Joined: Mar 2011
Posts: 1,037
Likes: 0
From: Florida
I installed AIS one week after buying the truck, used a rotozip to do the mod pictured below prior to install and then added fender sleeve about a year later. No Zoodad.
With the WW2 I can hear the turbo clearly at 10 psi and above (radio off). Friday I swapped in a 6637 and the same turbo sound is now audible above 7 psi. So far the noise from the 6637 hasn't been as great an increase as I was expecting.
With the WW2 I can hear the turbo clearly at 10 psi and above (radio off). Friday I swapped in a 6637 and the same turbo sound is now audible above 7 psi. So far the noise from the 6637 hasn't been as great an increase as I was expecting.
Cargo Master
Joined: Oct 2008
Posts: 3,330
Likes: 13
From: Eaton, CO
After I installed the 6637, I immediately experienced turbo flutter when pulling grade EMPTY. I used to be able to pull this particular grade with the OEM setup and it didn't flutter. Then the obvious drone at a specific RPM range. My wife was PISSED. LOL. If I can make this go away for $200 and not add an even louder wheel (WW) to the truck, I'm all for it. How does the cost of an AIS filter compare to the cost of a 6637? Is the filter change interval truly 2X the mileage of the 6637?
you can't fix stupid!
Joined: Mar 2008
Posts: 1,906
Likes: 2
Riffraff Diesel: AFE Stage 2 Pro Guard 7 Intake
Hotshot
Joined: Jan 2011
Posts: 18,849
Likes: 179
From: Puget Sound
I live in the desert (dusty). 20,000 miles between changes (filter minder tripped) before the 38R. Now? Not enough miles on the 38R to find out... but my stock turbo was turning 30 PSI (sensor on hot side of IC).