Anyone ever notice how the inside fender actually gets fed cold air?

[96Z71ECSB]

As some of you may know, I own a 1996 K1500 with a Vortec 350.
The truck originally came with a K&N CIA which I eventually removed in favor of a factory high capacity OEM air intake. I felt the K&N was sucking underhood hot air.
I didn't feel any loss of power making the switch.

However, I was poking around the engine bay of my truck the other day, when I noticed a plastic tube in front of the battery.
Low and behold, this tube feeds air from the front of the radiator support to the inside of the fender. Of course, we all know where the engine picks up cold air from.
I haven't removed the tube yet to see if it might be an air flow hindrance. I doubt that it is because, like I said, I felt no power loss going back to an OEM high capacity air intake.

I have never heard anyone mention this tube and it got me to wondering about the actual benefit of an open element CIA like the K&N.
I will get a good look at it eventually and come to my own conclusion about how it may or may not impede air flow.

I wasn't sure if any of you knew about this tube, but whether you do or don't, you all may want to take a gander at it anyway........if it's still there. There might be a hole where it was.
I would bet the earlier TBI trucks have it also.
I guess this post is more of an FYI than anything.
Comments are welcome.

Laters

 

[Ruger_556]

My '94 TBI has it too... In all honesty high flow intakes are a waste of money. You engine doesn't actually need the kind of air flow that K & N would have you believe.

 

[great white]

Yep, that's it's purpose.

It's there to feed the high pressure zone at the front of the vehicle in to the fender cavity.

If you stick your hand in the opening through the inner fender opening in the engine bay and reach back towards the passenger door, you will find there is a "wall" in the cavity.

What is happening is the high pressure air at the front of the vehicle is being ducted by the fender structure to provide a high pressure area at the intake opening. This makes it easier (and cooler) for air to make it to throttle body.

Or in my case, the turbo.

Air is actually "blown" into the combustion chambers, not "sucked". The pistons retreating in the bores create pressure below atmospheric and when the intake valve opens, atmospheric pressure rushes in. If you can increase atmospheric, you increase cylinder filling. That's also how blowers and turbochargers work except they create a much higher positive pressure than ram air effects.

It a very slight high pressure and it's mostly at highway speeds, but it's still there....you get a double bonus as the air is also cooler than ambient in the engine bay.

 

[96Z71ECSB]

I figured you guys may know about it. I didn't think it was a hindrance. Like I said, I felt no difference going back to a stock air intake.

 

[ShadowRejects]

My '94 TBI has it too... In all honesty high flow intakes are a waste of money. You engine doesn't actually need the kind of air flow that K & N would have you believe.

Yes..

http://www.youtube.com/watch?v=gCi2yo4UqPI

 

[sewlow]

Then here's this!

http://assets.hemmings.com/story_image/258261-1000-0.jpg?rev=2

http://www.opgi.com/common/C240193-lrg.jpg

http://www.oldsmobility.com/old/images/4_442s_article4th.gif

 

[great white]

Then here's this!

http://assets.hemmings.com/story_image/258261-1000-0.jpg?rev=2

http://www.opgi.com/common/C240193-lrg.jpg

http://www.oldsmobility.com/old/images/4_442s_article4th.gif

Ram air....in winter: ram snow.

 

[GrumpyOldTruck]

this is what had me confused about CAI so I decided to make my own kinda

I just capped off the part of the stock intake with part of a soda can and a 2in plumbing cap, where the vortec box would go
then bought a spectre performance air filter for like $30
then placed the lid back on the air filter box(not shown in pic)

I really do think it might have a very slight increase in acceleration. not sure about fuel economy

You must be registered for see images attach

 

[Steve's Chevy]

Wow im glad I seen this thread, ive been wanting to remove my K&N because it makes so much sucking noise it drives me crazy and if it gives me no gains then its just a noise maker....

 

[Horns]

I figured you guys may know about it. I didn't think it was a hindrance. Like I said, I felt no difference going back to a stock air intake.

All the GMT400's are designed like this. They pull the cold air from the fender. It's not a change you're going to notice through the gas peddle. It's just not a big enough change to notice with your foot.