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Discussion Starter #1 (Edited)
This is an excerpt from an old thread, brought back…

what is the air box mod
The $2 fix (a.k.a., Redneck Intake:D)

The Mod involves simply cutting an additional hole in the front side below the filter and just behind the headlight. There is a passageway built into the radiator support that when complete, will draw outside air up between the front air dam and the inner fender.

I used a handy little palm size offset air tool with a tapered plunging router bit, and cut open the lower side facing the front, without having to remove the intake box. To remove it, just pull up and rock fore/aft to release the rubber grommets on the underside.

I now have an unrestricted passage thru to this intake area down and between the front bumper and the inner fender. Looking thru this new inlet, to the right you can see the intake drop area. This area you're accessing is similar to the draw area of the 'scoop' sold as part of highly expen$ive intakes by an unnamed source. whistlin




I picked up from Lowe’s, a 2-1/4” x 42” piece of foam weather-stripping for window A/Cs for about $2.
Note; In this pick ('05LLY) you can see where the hole in the fender was sealed off, compared to earlier models where it was open. Open it seems, was determined to be a water/snow source, so it was changed and sealed off.



The foam fits perfectly, wedged between the air box and fender on the side, and between the air box and the Radiator support in front. Starting at the aft vertical side near the coolant tank, I then moved horizontally toward the front, and around the corner toward the radiator.



About midway of the air box, there is a perfect vertical flat piece on the core support to wedge against going down toward the inner fender to complete the seal. This final gap is wider than the others so, just fold over the remaining strip to double in size.




It’s just the right length with no trimming involved and nothing but cool air now for the intake, instead of the hot engine bay air as before. :neener



Note: ^^If your LLY intake looks like this, you need to also do the critical upgrade to the LBZ/LMM turbo inlet duct (a.k.a. Mouth Piece), which entails cutting back the intake flex tube (past the yellow warning sticker) so the MUCH larger inlet duct fits.

New (large) alongside Old (small):


Installed:
 

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this is for the greater good.

Thank you, you glorious m'fer
 

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Thank you for the post. Going to do this mod today..
 

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Getting rid of the HORRIBLE panel filter and garbage air box is the best mod.


Anybody else notice this airbox is almost identical to the ones that came on the 4.6, 5.3... shame on you GM


Edit: This is great if funds are low, or need a lil extra something quick for almost free.
 

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It is a good Mod and definitely helps!
 

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Getting rid of the HORRIBLE panel filter and garbage air box is the best mod.


Anybody else notice this airbox is almost identical to the ones that came on the 4.6, 5.3... shame on you GM


Edit: This is great if funds are low, or need a lil extra something quick for almost free.
What's the issue other than the terrible sealing?
 

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I'm doing this mod on my bro's 06 with a 5.3. Gm really didn't respect the diesels airflow needs
 

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Discussion Starter #10
Sorry, the pic host is having issues and some have dropped out. I'll try to update and see what's up. :poke[1]:
 

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Can anybody here that has done this mod tell me what your temperature difference between outside ambient ait temp and IAT (intake air temp read from your MAF) preferably on a hot day.
 

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I did a similar mod but i cut out the inner fenderwell under the stock foil "sticker" and then sealed around with 2"x2" a/c foam from the hardware store. Some spots i cut it in half so it was 1"x2" (under the box mainly). My iat on the edge insight reads 2-10 degrees over ambient, never more! Not bad for a redneck fix!
 

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Also, i didn't cut the airbox at all.
 

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Discussion Starter #15
The stick-on cover on the fender was added as a preventative for water intrusion to the airbox (issues from earlier models). This is why I left it in place, directing airflow from behind the lower air dam and forward of the fender liner, up and behind the headlight to large hole found in the core support.
 

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I did a similar mod but i cut out the inner fenderwell under the stock foil "sticker" and then sealed around with 2"x2" a/c foam from the hardware store. Some spots i cut it in half so it was 1"x2" (under the box mainly). My iat on the edge insight reads 2-10 degrees over ambient, never more! Not bad for a redneck fix!
Thanks for the data, now it seems this would be worth doing. Can anyone else post up data like this?
 

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I did a similar mod but i cut out the inner fenderwell under the stock foil "sticker" and then sealed around with 2"x2" a/c foam from the hardware store. Some spots i cut it in half so it was 1"x2" (under the box mainly). My iat on the edge insight reads 2-10 degrees over ambient, never more! Not bad for a redneck fix!
What does the IAT read when the fan is at full lockup? This where I found a problem.

When it's locked up it's blowing very hot air on the mass which also contains the IAT. I could see 160F on the IAT. I added a deflector/shield over the mass and elbow and it dropped the max temps substantially. In fact, if you look at the Bank cold air intake system they move the mass/IAT to the top backside of the intake pipe where it meets the mouthpiece. It certainly makes their system look better than it really is by getting the mass out of the fan wash.

I still see a rise but the temps come go up very slow and come down very fast. The hot fan air still heats the filter box and piping but at least it's not roasting the mass/IAT.

Here's easy test, monitor the IAT, get the truck nice and warmed up, pull over and drape something over the mass and elbow. You will see the IAT drop.You don't need the fan locked up to test this. If it locked up just put your hand on the elbow at the mass. The fan is blowing directly on it.It makes the IAT lie.
 

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What does the IAT read when the fan is at full lockup? This where I found a problem.

When it's locked up it's blowing very hot air on the mass which also contains the IAT. I could see 160F on the IAT. I added a deflector/shield over the mass and elbow and it dropped the max temps substantially. In fact, if you look at the Bank cold air intake system they move the mass/IAT to the top backside of the intake pipe where it meets the mouthpiece. It certainly makes their system look better than it really is by getting the mass out of the fan wash.

I still see a rise but the temps come go up very slow and come down very fast. The hot fan air still heats the filter box and piping but at least it's not roasting the mass/IAT.

Here's easy test, monitor the IAT, get the truck nice and warmed up, pull over and drape something over the mass and elbow. You will see the IAT drop.You don't need the fan locked up to test this. If it locked up just put your hand on the elbow at the mass. The fan is blowing directly on it.It makes the IAT lie.
Good point I have been assuming that it is the hot air from the fan blowing being taken into the intake. I have seen 180* IAT many times. My K&N has the MAF on top of the tube maybe it has the same problem.
 

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Good point I have been assuming that it is the hot air from the fan blowing being taken into the intake. I have seen 180* IAT many times. My K&N has the MAF on top of the tube maybe it has the same problem.
Yeah, I was seeing the same thing and initially thought it was drawing engine compartment air from between the air box and fender (there is a gap there.) The 6.0L had a seal but I suspect the 6.6L D/A draws so much more air it was easier to just remove the seal than to enlarge the fender slots.

I install the TxC CAI seal and it really didn't change much. If the fan was locked up the IAT would still rise. Then I thought that maybe the fan is blowing air into the gaps and opening in the fender so I seal them up. Still no real change.

I then got out my IR temp gun and checked the temp of the mass, airbox and elbow. Ah ha! That's nowhere near ambient and in fact damn hot. I draped a towel over the elbow and mass and the IAT dropped. I repeated it a couple of times and got the same result. I then built a shield and it helped tons. I also temporarily moved the mass up top like the banks and saw more improvement but in the end, unless the IAT is totally isolated from the engine compartment heat, it's going to be affected by something. I figure the shield is as good as I need. I can still see 140F with the fan locked up for a long period of time but once it unlocks the IAT drops quickly to under 10 over ambient.
 

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terryk great info. I'll look into this before I spend any money!
 
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