Hey, I'm new to the forum and just want to say I love all things Dodge. I havea Grand Caravan with a 3.3 ltr and notice it lacks a bit of power. Love the stow n'go but wouldn't mind some more power. Has anyone tried a K & N air filter and do they really work?

 

I installed a cold air intake and k&n filter on my 2000 GC. It did make a difference in horsepower and fuel economy. I also use mobile one synthetic. The trade off will be a slight increase in the sound of air being drawn in to the intake, but it isnt enough for me to switch back. I noticed a few extra horses right away, and i went from getting around 335 miles a tank to about 380 - 385 a tank. I am very satisfied, if you try it let me know back how it does. Sounds like you have a newer GC and I'd be interested in knowing. I bought the filter on ebay and the tubing at autozone by a company called "Spectre", they make several lenghts and bends and all the stuff you need.

 

Before buying the KN or any CAI
consider doing a couple acceleration runs
without the stock filter in the filter box.
This will give you an idea about any potential gain
which you will find is relatively small...kinda like
the difference in horsepower your engine makes
between a 65 degree morning and a 85 degree afternoon.

A better test is to run a new fresh paper filter
against no filter.

A common trick in magazine dyno tests
comparing KN-like filters to stock paper filters is to do the first
dyno test on an old and heavily clogged paper filter, then do the
second test on a brand new fresh KN filter.

"oiled gauze" cleanable filters like the KN
do start out at slightly lower restriction
but more quickly clog up because they have much less
surface area than a multi-pleated paper filter.

None of the auto makers...including performance companies
like Porsche, BMW, Mercedes AMG, etc
have found in any test that oiled gauze cone filters
give either better performance, longer life, or improved MPG.

See old posts below for more info:

 

This post has more information rather than less.
It is designed to give you tools to spend money effectively.
If you have already made a purchase
there is a chance that reading this
may make you unhappy or emotional.

Don't blame the aftermarket air intake for not giving you a MPG increase.

There has been lots of careful scientific testing of all kinds of air intakes
and the result is that they neither increase/decrease MPG on gasoline engines.

But you can also reliably predict that if 1000 customers buy an air intake
that
DOES ABSOLUTELY NOTHING
and then these customers check their next tank to see if it improves MPG,
then 500 of these customers will see an improvement,
500 customers will see a decrease,
and ONLY if you could collect and average all 1000 of the next tanks
of gasolines would you find a true average that would only be 'near' zero.

The same thing would be true if you flipped a coin 1000 times.

If less restrictive air inlet system improved MPG,
after the last 20 yrs of C.A.F.E.
(Corporate Average Fuel Economy)
government MPG standards,
you would now see massive air intakes with 2 foot high by 4 foot wide
openings - even on the smallest 4 cyl compact.

Honda,
in a spirit of fierce pride,
told its student engineers to do everything possible on the
Insight Hybrid to get the greatest possible MPG
- they were in a 'bragging rights' competition
with Audi CEO and Porsche's grandson Ferdinand Piech
who was having his Audi student engineers build the
four seat Audi A3 aluminum body/3 cyl diesel
as the world's highest MPG car,
called the '3 Liter Car'
because the Audi A3 only needed 3 liters of fuel to go 100 kilometers.
This is about 83 mpg.

Honda used every known trick in the gasoline engineering book to get over 70
MPG to beat Audi's fuel economy of 3 liters per 100 km on diesel. Notice that
Honda was starting out about 20% behind because they were trying to make a
gasoline engine powered vehicle beat a diesel power vehicle for 'world
bragging rights.'

Go look at the air intake of a Honda Insight.
What do you see?

If you don't want to trust just the Honda,
go check out the Toyota Prius, Lexus 400H and Ford Escape Hybrid air intakes.

See a trend?

Check out the 2006 BMW M5 air intake for a 'ram air' design on a vehicle that
can reach 'only' 190+ mph. Note that the BMW engineers NEVER claim this intake
improves MPG, even though they list dozens of other engine features on the 5L
V10 that do improve MPG.

http://www.seriouswheels.com/2006/20...t-1024x768.htm

Got a buddy with a Dodge Ram with the overhead trip computer?
(His truck does not have to be exactly the same as yours, but the closer the
better)

Since you are making a modification with hopes of getting better MPG
why not do a "before & after" test?

Do a 'before test' with both trucks
* you and your buddy fill up at the same gas station and put the same air
pressure in all tires
* Pick a highway without too much traffic and hopefully where the wind is a
head wind or tailwind (side winds mess things up)
* Your Ram and your buddy's Ram follow one another staying at least 6 vehicle
lengths apart
* talk to one another with cell phones or walkie talkies
* drive at the same speed
* reset the overhead computers at the same time
* drive at least long enough to burn up 2.5 gallons
* exit highway, turn around, and continue the test in opposite direction
(this is to partially cancel out wind direction)
* write down average MPG on overhead computers at end of run
and compare this to the gas pump numbers and odometer mileages.

After doing your modification
redo the test the same way as above,
hopefully at a time of day where the temperature is about the same as the
'before' test and the wind speed & direction is not a problem - which you
can check here:

http://tribunewx.wunderground.com/US...WindSpeed.html

Note that in the above weblink you can type in your zip code and get exact
wind, temperature and other weather data.

The value of your buddy's pickup being along on is that on this 'after' test
if his MPG is greatly different you should suspect something has gone wrong
like strong cross winds, a change in temperature, tire air pressure, etc.

If you want to test two trucks against one another that are already modified
like comparing 3.55 differential gears to 4.56 gears
or an underdrive pulley, syn versus dino oil, tire air pressure, thermostat,
SuperChips, etc......
you can modify this test slightly for even better accuracy.
Swap two tires from one truck to the other.
Now both trucks have the same 'average' tires.
Weigh the trucks and add weight to the lighter truck to make them even.

If you really want 'gold standard' accuracy that you can trust
(or if you are measuring a small effect like a thermostat)
then swap the mod over to your buddy's truck
and do the tests another time with your truck as the 'control'.

If you are presently thinking:

"Wow, who would be that careful for a lousy MPG test?"

then just think about a dragstrip
which will have:
carefully measured distances,
highly accurate timing trigger by light beams,
know its altitude,
have a weather station,
and have a computer program to 'adjust' results for weather conditions.

All this type of MPG test is doing is applying the same standards to MPG
that is expected when someone brags about their vehicle's ET or MPH in the
quartermile.

By doing a test this way you are doing a simplified version of a
SAE/TMC Type IV fuel economy test RP 1109.

Here the SAE stands for Society of Automotive Engineers and
TMC stands for Truck Maintenance Council which is a group
of professional 18 wheel truckers who have banded together to share
information. RP stands for recommended procedure.

If you watched the 'Mythbusters' TV shows where twice they have done some MPG
testing, first on a pair of F150s and later on a single Dodge Dakota...then
you saw a 'flashy' version of the SAE/TMC Type IV test on the F150s, and later
a SAE/TMC Type I test with a calibrated FlowScan meter on Adam's Dodge Dakota.

Credit for inventing a 'reliable' MPG test like this goes to many, but
especially Claude Travis, known to his peers at TMC as "Mr. MPG,"
who has spent 37 years managing the operation, maintenance and testing
of heavy-duty, on-highway vehicles. Highly regarded for his exhaustive
research in the field of heavy-vehicle fuel-economy, he is principal of
Claude Travis and Associates, Fleet Consultants, Grand Rapids, Mich.

In the actual SAE/TMC type IV test they also take the temperature of the
fuel both before and after, because a gallon of fuel coming out of an
underground tank at 57 degrees F will expand/contract several percent
as it approaches that day's air temperature.

If you are interested in learning more about this
there are also SAE/TMC tests I, II and III
and no doubt someday an even better test V will be invented.

For a second opinion on what is written below
go to
http://www.fuelsaving.info/debunk.htm

 

Before spending considerable money on a cold air intake,
read what the volunteers found independently testing
KN Air Charger, KN drop in, Volant, Mopar and Airaid 360
aftermarket air intakes against the stock factory airbox
on 5.7 V8 Hemi's in Chrysler LX's

http://tinyurl.com/2j4gx3

Keep in mind that the factory airbox
on a Ram pickup 5.7 Hemi engine is even
bigger and less restrictive than the factory box on a LX.

To save everyone some math
the average of three runs
of the stock factory airbox and paper filter dyno'ed:

280 HP with a standard deviation of 3.75
(corrected to standard pressure and temperature)

The only cold air intake testing better
was the KN Air Charger at
281 HP with a standard deviation of 4.15

Since the average of all 18 dyno runs
where an air intake design
was tested after a standard PCM reset was:

279 with a standard deviation of 3.24
(runs number 4 to 6 plus runs 10 to 24)

you really can't say with certainty that the
extra 1 HP for the KN Air Charger was 'real'
because even a well designed wheel dyno
that is well maintained
and has a great operator
can't be depended upon to repeat that close.

279 HP with a standard deviation of 3.24
means in simple terms
that if you ran exactly the same engine exactly the same way
100 times, then
98 of the runs would 'scatter' between
a high of 285.5 and
a low of 272.5
(which is 279 plus and minus two times 3.24)

1 HP gain for the KN Air Charger versus
280 for the factory air box
is below 1% difference
and this rear wheel dyno
seems to be varying over a range of 12.96 hp
which at a bit less than 5%
is actually admirable for repeats on a wheel dyno.

What can you say with certainty?

You can say:
1) they have fancy colorful paint jobs

2) they make more noise than the factory intake

3) 50% of the buyers who check their next tank of gasoline
will 'by chance' find a higher MPG than the last MPG they remember.
Of the other 50% who 'by chance'
find their next tank of gasoline's MPG is lower,
a considerable number will think something like
"the computer is still learning" or
"I must have been driving with a heavy foot"
and will go on to give the CAI another chance
and watch future tanks of gasoline
for their wishes to come true to justify their purchase.
Since MPG improves on vehicles as they age,
(because their pistons' ring tension wears looser
and their tire tread depth wears down and gives lower rolling resistance
.....the well known 'break in' effect)
these buyers will eventually find their MPG has gone up,
and they give the credit to the intake for the increase.
Very few will ever take the CAI off for awhile to check to
see if the MPG stays the same, or goes down.

 

Two great American brothers
with only high school educations
had a DIY project
that they eventually called the 'Airplane'
but like the Wright Brothers
you need to do your DIY project with careful testing.

If you want a real answer you can trust about an air intake design,
then........

Go down to Sears and buy one of the $30-70 multimeters with the temperature
probe. Sometimes they are on sale for $19

http://www.sears.com/sr/javasr/produ...seBVCookie=Yes

or

http://tinyurl.com/ywcsxv

http://s7.sears.com/is/image/Sears/0...6&fmt=jpeg

Later you can use this relatively cheap multimeter and its Type K thermocouple
to 'balance' your exhaust gas temperatures by swapping around the highest
flowing fuel injectors to the highest flowing intake ports....but that is
another story.

Then buy one of these $30 gauges that can measure low pressures and buy a
length of plastic tubing about 10 feet long to attach to it:

http://flw.com/olash2.htm#1490

Get the 30/30" pressure model.

If you don't want to spend this money you can also make a simple "U tube
manometer" with just a 20 foot length of clear plastic tubing and a yardstick:


Now drill small 1/16 th inch diameter holes in your stock air filter housing
and air inlet tubing,
like at:

1. at the begining of the inlet tube
2. in front of the air filter element
3. behind the air filter element
4. near the throttle body connection

Put a fresh new air filter element in your stock filter box. Go out on a road
with little traffic and measure the temperature and pressures at your small
hole test points of the stock system when the engine is at wide open throttle
through the 2000 to 6000 rpm range.

If you find between two points that the temperature goes up, then the air is
picking up heat in that length between the two points. (i predict you won't
find much heat pickup)

If you find that the pressures go down between two points then there is
restriction in that section, like across the filter element ( i predict you
will only find a small restriction across the paper element of the filter)

Now try moving the air inlet to the stock filter box from its stock location
to other places - like the grille top or bottom. Look for a place where the
pressure is highest and the temperature is lowest. (I predict you will find
that the cavity behind the firewall and below the windshield will be best -
this is also where your air vents pick up air to ventilate the truck's cabin)

Now, if you are a bit more adventurous try the following experiment:

With all the stock air system in place, put the truck in 2nd gear and measure
with a stop watch how many seconds it takes to accelerate from 3000 rpm to
6000 rpm with wide open throttle. Do this test 3 times and average the
result.

Now if you are a little more daring and have found a clean road with little
dust in the air, think about doing the following 2 tests (it is optional but
informative)

Do the same test from 3000 to 6000 rpm, but with the paper air filter removed
from the box, and the box closed back up. This is the 'no filter but cool air
pickup' test.

Then do the same test, but with the air intake system removed and the throttle
body opening sucking the hot air from underneath the hood. This is the 'no
filter hot air pickup test.'

{The above tests sound dangerous without an air filter, but I can tell you
that many highway patrol officers removed the air filters on their cars in the
1970s. I have personally seen people pour uncooked rice down carburetors to
scour out carbon deposits. Lack of an air filter over long periods will cause
the bore walls and piston rings to wear out much quicker, but a quick test has
little effect unless you are unlucky enough to get a large chunk of something
down the throttle. If you are worried you can cover the throttle opening with
some eighth inch hole window screen material or mesh stocking}

Now go order the aftermarket air inlet systems of your choice and repeat the
pressure, temperature and 3000-6000 rpm acceleration tests in 2nd gear. Send
back the systems that don't do as well as the best for a refund of your money.

Report your results to automotive forums.
You will be a hero to some,
the worst possible news to others selling junk.