I have a 97 F250HD with a stock 460 engine, and I have been looking into upgrading my air intake
63-1014 - K&N 63 Series Aircharger Kits, Performance Intake Kit direct from K&N

My only question is, would this increase or decrease my gas millage? I have asked a few friends and some say it will increase since the engine does not need to work as hard, and others say it will decrease because it allows the engine to get gas faster.

Both seem to make sense to me, so I'm not really sure who is right?

 

Most K&N products are for performance. We have never put any K&N parts on a truck but when we had our 90 Ford Van with a 351 Windsor that had a K&N filter when we bought it and it didn't do anything to the gas mileage nor performance. This is a diffrent engine and filter set up so I don't know for sure.
Trav

 

If you do an online search for “air filter test” there is a lot of very good information. IMHO, the CAI units are NOT WORTH THE $$! Unless you are talking about a system that was specifically designed for a specific application there are very little hp/tq gains actually achieved in a street use vehicle and there are very few docs that these mfg’s can produce that actually show an increase in hp/tq in the power-band range of a relatively stock street vehicle. The 5.4 V8 for example if close to stock can only suck in a maximum of 480 cfm and a flat panel filter will flow 500 cfm, there is simply no way any CAI on a relatively stock engine can increase the air flow enough to make any difference in MPG or HP.

If you look at the dyno charts from many of these supposed HP/TQ increases, they are typically around 5%-7% at peak rpm ranges…….guess what, 5% is a standard deviation even amoungst mfg dynos and the most important item is……these “expert tuners” (at least most) do not have or choose not to test their results (in comparison to the oem intakes) during actual vehicle motion (or simulation- such as a wind tunnel) as the oems do.

I would avoid oil impregnated filters. While they have their purpose in off-road applications, Ford/GM/Dodge all have “watch-out” bulletins where the oil has contaminated intake sensors. - they even have a training video for the techs on this (flatratetech.com) .....I am persoanlly the recipient of this going back to 1997 on my (then) new Cougar Sport V8...K&N failed to provide any support for this mulyiple event that was well documented by Ford....and the filter was purchased direct from K&N.

Testand Corporation conducted an ISO standards test on automotive air filters which can be viewed at this link: http://www.dieselbombers.com/chevrol...r-testing.html. All I can say is this explains in detail the actual performance results from these supposid CAI expertly designed systems.

If you look at the flow data, WIX HP filters flow 98+% of K&N and have a much smoother flow post filter plus excellent filtering, for a fraction of the price! The OE’s have an excellent air intake system. What many view as an issue (is the plastic intake tube with its noise canceling design) actually increases air pressure. It is the same hydraulic concept used by fire fighters creating water supply where psi is low. By having the air cross the path at a 90 degree angle, the pressure is increased proportionally. Fire fighters use what is called a “4-way valve” or “Blake Valve” at the hydrant where the water is cycled through the fire engine (pump) and sent back into the valve crossing the water flow at a 90 degree angle. In this case it also acts as a sound canceling device! At low speeds, this can reduce the flow a tad (which is what most “feel”), but in terms of peak hp/tq, a good high flow filter is all that is needed. You can use a WIX OEM HP replacement filter in the OEM plastic manifold box and either remove the plastic tube and replace it with a piece of pipe/hose, etc or remove the tube completely and replace the tube by building an air ram type intake into the air box manifold (where the pipe use to attach)- make sure it terminates above the fan shroud to avoid water intake or fan induced pulsations

 

Thanks a lot for all the info Beechkid. So you think I would be better off saving the cash and just getting a performance air filter to fit in my stock air box, instead changing the whole filter system?

 

Best bet is to save the cash and replace your paper air filter with a new one every 12-15K miles. They aren't that expensive and you wont need to drop $20-$30 on a cleaning/recharge kit to service a reuseable one.

 

That price is so inflated for what you get. Those are on eBay for like 60$.
A k&n dropin filter is all you need. Those go for under 20 usually.

Search the forum and you'll see that the stock airbox isn't that bad. And your 460 already draws fresh air from in front of the radiator.

Do a complete tuneup with plugs wires cap rotor wires coil fuel filter, can of seafoam in each tank, half can in oil, half can in trans (drive til both tanks are empty then change oil and flush trans) Drain and refill transfercase, drain and replace rear diff fluid (pull cover, maybe replace with new 08 alum finned diff cover)
Turn up timing to 10-12 and see if it has any detonation with the fuel of your choice. I'd prefer you do this on a hot evening.
After that you should notice quite a difference.

 

If you haven't done so already take off the air intake tubes and remove the air horns, I'm not sure what their original purpose is but they are restrictive.

 

Thanks a lot guys,

I'll probably go with a K&N filter for my airbox and a tuneup. Inspections are pretty strict around here so I'm not sure I could remove the intake tubes(something with the emissions I think) But I will look into it. And I know it has a paper filter at the moment but I don't know the last time it was changed since I've only had it for 2 years.

 

All you do is take the intake hoses off and there's a plastic bit in the middle of the whole setup. Pull the hoses off that and trim the horn looking things off making sure to leave enough lip to clamp the hoses back on. There's a little ridge cast in it so I just trimmed right before that with a hacksaw. It was a bit slow but it was smooth and straight. Cleaned it up with some sandpaper and made sure there wasn't any shavings left behind to get sucked down into the engine and put it all back together. It won't do anything to your emmisions and will flow all the air your engine can handle.