OK, I just have to add my opinion, first the math question is simple, "PI r Square"
I have not seen nor understand why anyone would put dual 2.5 on a 3 inch exaust at the end. It is correct that any change in direction (in eng cal it is called ulage) The is a reduction of velocity and resistance to flow. (The whole idea is that the lower the air temp the higher the density, itimproves eff. of compression cycle but hasoppisite effect on combustion and after products)
The home made CAI is at best a product the man had fun making. although his cost to make was close to the EBAY price of a cheap intake. The noise generated by these is much more than the preformance increase.
Why if you want to drag race would you ever buy a full size truck, with a stock drive train. Then put crazy cash into mods. Buy a used truck with a blown motor and build it up along with the drive train and suspension. You may not have the newest truck but you end up with the fastest.

 

These people are not buying these trucks to drag race.
They are buying these trucks for regular use, then trying to find ways to improve them.
What is wrong with that.
Not to mention, someone doing it there self may finda better design than what's already out there.
Especially the cheap ebay ones, which BTW are NOT CAI even though they say they are.
They are a very short tube with a filter on the end that pulls HOT air from the engine bay.
Worst case of false advertising I have ever seen.

The one he made himself is going to flow better than the original regardless of the 90 deg. bends.
The stock box has accordian designed tubes which cause a lot of turbulence in the intake.
His does not.
The stock box already has it's own share of wierd bends. The air enters the stock box, goes through a 90 deg. bend into the stock restrictive filter, makes another 90 deg. turn and exits the box intoan accordian style tube.
His has less bends and restrictions than the stock box period. And it draws TRUE COLD AIR from in front of the engine, not FROM the engine bay like most ebay "CAI"'s ( BS ).

His design will give him better performance no matter what all the naysayers say.
Can it be improved upon? Yes.
Willan improved designmake that much more of a difference than his? NO.

The PVC like said before is WIDELY used in construction where temp degrees vary wildly.
It may benefit from heat wrapping.
That' what Iplan to doWITH MY HOMEMADE PVC AND REAL K/N INTAKE!
And I did pick up 1 or 2 mpg and a bit more noticable throttle response.

Good job on your homemade intake. F*** all the a**holes that think it is pointless.

Apparently, a throttle body spacer is pointless also, DubadubDodge .

And using your reasoning, DubadubDodge, why put a pully kit on your truck?
Don't you thing all those professionals that designed your truck put countless hours into the proper sizing of the pulleys?
And your truck was not design to run 22" rims either.
And your Dual 10" MTX's will probably cause excess vibration inside your cab causing something to come loose and fail.
And your halo projectors will probably blind one of US coming from the opposite direction causing us to loose control and have a wreck.
And your Flowmasters are probably irritating all your neighbors.
And as said before, your chip probably voids your warranty, if it's still in force.

Come on people!!! Give the guy a break. He did a good job. Looks great, and probably works as expected.

Show a little support for new innovations. And STFU if you don't know WTF you are talking about.

 

This is because typical aftermarket "CAI" are actually "HAI" -- HOT AIR INTAKES. BS crap.

At least his is a TRUE COLD AIR INTAKE.

So, his has the benefit of smoother inner surfaces AND COLD AIR.

 

The 02' Model does not have a air temp sensor... Just FYI

 

an old post:
----

Heard of the 'Ram Air' effect where the speed of the air hitting the vehicle
builds up pressure in a forward facing air duct and helps 'supercharge' your
engine a bit. ?

Well, at 'typical' street speeds the effect is very very small.

The formula for that is:

Inches of water pressure from Ram Air = (mph) times (mph) divided by 2025.

So at 70 mph the ram air effect is:
(70 mph) times (70 mph) divided by 2025 = 2.4 inches of water.

So the very best possible air inlet tube designed for Ram Air would actually
have a positive pressure of 2.4 inches of water.

How much pressure is an inch of water ?

One psi of pressure is equal to about 28 inches of water.

You can get this by dividing the cubic inches in one cubic foot ( 12 x 12 x
12 ) by the weight of one cubic foot of water ( 62.4 lbs).

The air pressure around us is averages about 14.5 psi at typical heights above
sea level.

So another way of looking at it is that the air pressure around us is about
400 inches of water. ( 14.5 x 28).

So the best Ram Air system at 70 mph gives you a boost of about 2/400 or one
half of one percent. Small.

Ram air started in airplanes where it means more. An airplane going 300 mph
gets a boost of:

300 x 300 divided by 2025 = 44 inches

This is a percentage boost of 44/400 or about 11%

Want a challenge?
Consider your tires.
Some strange facts:
At 70 mph the center of your tire is moving 70 mph.
The bottom of your tire where it 'grabs' the pavement is moving at 0.1 mph
The top of your tire is moving forward at 140 mph.
If you could put a 'Ram Air' inlet right at the top of the tires (where it is
horribly dirty and wet) you could get a significant air pressure boost.....