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2006 chevy
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I'm going to bring this one back up to the top.

Looking at the stock "CAI".... I noticed a few things:
- The factory did a fairly well job of sealing off the intake from the engine compartment air. There's a few ratholes, but nothing so gaping-large that they can't be plugged with a little closed-cell neoprene. Funny though, the biggest rathole on the top is being addressed by GM and their appropriate supplier. While at the GM-VEC today for a weekly meeting, I was looking over a white SS in the lobby. There was a GM Engineer and supplier with their heads in the engine bay, pointing to the rathole and discussing options for closing it off, asking for cost/timing, etc.

- The stock round "hole" underneath/behind the RH headlight is incredibly small. Look beyond the rectangular mesh grille, and you'll see this itty-bitty hole that is allowing sufficient air into the intake to produce 395hp, but likely not much more than that for anyone considering engine-mods to the LS2 (stage-II 243 heads...yum). Who wants to be the first person to enlarge this hole? This round hole can easily be notched wider to make it more oval-track shaped. If its done clean enough, not even a GM tech would notice it.
 

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If you look close between a 5.3 air cleaner and the TBSS, they are not the same unit as mentioned earlier. There carry different part numbers and visual differences on the TBSS are:

Taller box
Air cleaner sits higher (i.e. straighter flow path)
Much larger opening - Obviously
Provisions in the washer bottle to hold the side close out panel
Side close out panel (not completely sealed but looks to be effective)

In addition, the rad. close out panel seals the top of the box. The system is very functional when sealed properly.
 

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2002 chevy trailblazer_ls
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The stock round "hole" underneath/behind the RH headlight is incredibly small. Look beyond the rectangular mesh grille, and you'll see this itty-bitty hole that is allowing sufficient air into the intake to produce 395hp

I'm curious, on the SS, did they close up the gap between the bumper fascia and the bottom of the headlight? That's where my home-made CAI relies on its air source. On mine (mere mortal '02 4.2), there is a 1/2" X 14" gap to let air straight into the bottom of the "box" I formed when I sealed and closed off the area to isolate it from the engine heat. There are other gaps and holes too where it can get outside air, but this is the main source.

Here's a pic of mine backlit from behind the headlight with a shop light to try and highlight the gap ...

 

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2005 chevy trailblazer_lt
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tblazed said:
The stock round "hole" underneath/behind the RH headlight is incredibly small. Look beyond the rectangular mesh grille, and you'll see this itty-bitty hole that is allowing sufficient air into the intake to produce 395hp

I'm curious, on the SS, did they close up the gap between the bumper fascia and the bottom of the headlight? That's where my home-made CAI relies on its air source. On mine (mere mortal '02 4.2), there is a 1/2" X 14" gap to let air straight into the bottom of the "box" I formed when I sealed and closed off the area to isolate it from the engine heat. There are other gaps and holes too where it can get outside air, but this is the main source.

Here's a pic of mine backlit from behind the headlight with a shop light to try and highlight the gap ...


Yes they did reduce the gap size between both the headlight and bumper and the bumper and the fender

With the SS concept, they eliminated the gaps completely, but the plan was to shorten the gaps as much as possible, which they did.
 

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2002 chevy trailblazer_ls
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I know a lot of people complained about that gap, but I found a way to put it to use!

That gap 1/2" X 14" equals 7 sq. inches, the same area as the opening of the 4.2L 77mm throttle body. With all the other holes and gaps, it shouldn't be gasping for air anyway.


So on the SS they added a vent hole in the grille crossbar to let in more air where the headlight washer nozzle ass'y used to go on those so equipped.

I remember something about the CAI system for the SS in earlier info that would take in air from openings under the bumper or some such. An idea that didn't make it. That would be a good aftermarket add-on.
 

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2002 isuzu trailblazer_ss_3ss
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If you think about it, the stock V8 TB's (LWB only until 2006) did not have grill vents, and made 300 HP. Like many other airboxes I've looked at, the air is pulled from all around the inlet. If you pull the top beauty cover/baffle and look at what is directly ahead of the airbox, yoo'll see light popping through from outside the vehicle all over the place. That's probably where the bulk of the air comes from, in addition to from under-hood sources like the base TB V8's do. They must have done the hole in the grill to make up for choking off the air coming into the 'box from the engine bay (a good thing). That, and since the grill vent is RIGHT in front of the airbox, it has to be feeding nice cool air.

I think with a Dremel you could cut the provisions for the headlight washer out, not have it noticeable to a dealer snooping for warranty-busting mods, and pick up some more cool air. However, I doubt you will notice any performance difference. Considering how much air it HAS to be getting from other sources to make 395 HP, I can't see hogging the headlamp hole out making much of a difference.

tblazed said:
The stock round "hole" underneath/behind the RH headlight is incredibly small. Look beyond the rectangular mesh grille, and you'll see this itty-bitty hole that is allowing sufficient air into the intake to produce 395hp

I'm curious, on the SS, did they close up the gap between the bumper fascia and the bottom of the headlight? That's where my home-made CAI relies on its air source. On mine (mere mortal '02 4.2), there is a 1/2" X 14" gap to let air straight into the bottom of the "box" I formed when I sealed and closed off the area to isolate it from the engine heat. There are other gaps and holes too where it can get outside air, but this is the main source.

Here's a pic of mine backlit from behind the headlight with a shop light to try and highlight the gap ...

 

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2004 chevy trailblazer_lt_ext
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I'm not sure about the SS, but those of us who have opened up the area between the headlight and lower running light/turn signal and added grille vents to our non-SS TBs will tell you that the vents make a difference. :m2:
 

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FattyTBEXT said:
I'm not sure about the SS, but those of us who have opened up the area between the headlight and lower running light/turn signal and added grille vents to our non-SS TBs will tell you that the vents make a difference. :m2:
Thats exactly what I want to hear!!!:D

I havent gotten around to finishing my airbox project yet, so for the time being I am driving with no airbox whatsoever. I know the hot engine air, yada yada yada, but actually I think I am getting more performance out of it. It might just be me, but the fan seems to push the cool air to the sides a lot, and a fair amount gets to the filter. Having the front completely open helps too, but I really want to get my box back on or get an intake.
 

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2006 chevy trailblazer_ss_lt
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ScarabEpic22 said:
Thats exactly what I want to hear!!!:D

I havent gotten around to finishing my airbox project yet, so for the time being I am driving with no airbox whatsoever. I know the hot engine air, yada yada yada, but actually I think I am getting more performance out of it. It might just be me, but the fan seems to push the cool air to the sides a lot, and a fair amount gets to the filter. Having the front completely open helps too, but I really want to get my box back on or get an intake.
I assume its a little chilly in seattle this time of year so you're probably ok for another few months
 

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2004 chevy trailblazer_lt_ext
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jimmyjam said:
I assume its a little chilly in seattle this time of year so you're probably ok for another few months
Yeah I'm running my FFAI right now too. F****n' Freezin' Air Intake. :yes:
 

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Here are images of the grill intake with the grill removed. Don't think I've seen these images on the net yet.. so here they are for reference:

Passenger Side Intake. (The driver's side is identical opening, but obviously there's nothing behind it.)


Rear of the Passenger side grill.


Rear of the Driver's side grill.
 

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2006 chevy
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TB SS said:
Passenger Side Intake. (The driver's side is identical opening, but obviously there's nothing behind it.)

Now its time to make that round opening just a li'l bit bigger / wider (oval-shaped).....!!
 
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