Air Filters

[Boatnut]

Hi again,
Does anyone know for sure or "Have a Gut Feel" whether or not the aftermarket air filters such as K & N really do anything .?? All sorts of claims are made but I dont know anyone personally that actually has one.
The application would be on a Silverado with the 4.8l engine,Auto Transmission , 1/2 ton PU
Thanks for your input,
Cheers,
Boatnut

[tpl]

Anything that allows the engine to pump more air will help a bit PROVIDED THAT  the computer will adjust for more fuel and the exhaust has enough capacity to get rid of the extra gases.  So yes. The extra power you get may be very little without doing other engine work. 5 bhp maybe.

Specifically K&N  and other "oiled" air  filters CAN cause damage to the mass airflow meter by contaminating it with oil if you reoil the filter a bit too much. The MAFs usually can be carefully cleaned rather than replaced.

Barrie will vote for them I think and he is usually right about GM engines.

[articsteve]

As tpl said, those type filters let more air in hence more power.  How much power?  At what cost?

I don't use them in cars.  Too much road dust.  Oiling can be a major problem as mentioned.  Power increase, if even noticeable not worth the cost and potential intake problems.

You want power, change the exhaust.  That is where the bottle neck exists.

[barrie1]

The K&N filters will help your engine but at the cost of them sometimes you don't save enough to make it worthwhile. The 4.8 is a good engine and should give you descent fuel milage in its own right. I have a 4-4.5"  high  x 14" wide K&N air filter for my truck but am currently useing a dry cartridge type as its just as cheap to use and no cleaning to do which can be a messy job sometimes. You might be able to reverse the top of your breather cover to help give more airflow altho you will dirty the filters much faster if you do. It won't seal like normal this way and will probably stick up slightly higher which will also create a louder noise as well.  If you can it will allow much more airflow which will help to some degree. I agree with larger exhaust as that will help increase the HP as well as the milage to some degree also. When towing Headers will help the engine breath better and also increase the milage somewhat.  Depends on the rules for your province if you can use them tho for this purpose as all Provinces may vary on these regulations.

[Boatnut]

Thanks Guys,
I looked at Summit Racing's website for Headers , WOW what a bewildering selection not to mention the programmers etc.
I am starting to suspect that the sky is the limit and one spends what one wants and hopes for the best.
Consider this , we are going to travel from Vancouver ,Bc to Halifax, NS down into the states for a little ways then back to BC.This is towing a light weight trailer. I have my doubts that payback would be achieved by the time we get home, whats your feelings ??
Cheers,
Boatnut

[articsteve]

Only if your exhaust was completely shot would I bother to spend the cash on an aftermarket exhaust on your vehicle.

What I would do is change the tranny filter and exchange all the fluid and make sure that a tranny cooler is installed. They are easy to install in pickups and cheap.

I would also keep to the stock paper air element.

I'd also throw a fresh set of pads on the brakes.

[tpl]

As your trip is a minimum of 13,000km I would bring the next long service ( plugs, oil & filter, greasing if required, balance the tires, check the spare, wiper blades etc) forward and start the trip with new SYNTHETIC oil and new spark plugs and an air filter as Artic says. That combination may actually notice on fuel economy on a long trip like that.

[articsteve]

Personally I'd pass on the "synthetic" oil and buy a case of 12 litre Esso SAE 30 at any Esso bulk dealer and take it with you or the remainder of it after fresh oil change.  For summer time you can skip the 10W or 15W stuff.  Also exact same stuff found at Crappy Tire in their brand "Motomaster" if you run short.

[barrie1]

I would suggest going with the proper grade of oil and a good name brand to use in the engine. The headers will run you around $250.00 - $300.00 for a decent set on the truck and will help with the fuel milage for sure. Hooker are a good brand but pricey as I would shop around further. BlackJack don't give you a decent warranty for Canada. I suspect you have a good sized tranny cooler already on the truck as it does have the tow-haul feature all ready in the tranny setup on this truck. With up-to-date spark plugs you should be all set to drive for miles and should have very little trouble at all. 

[ktm525]

Personally I'd pass on the "synthetic" oil and buy a case of 12 litre Esso SAE 30 at any Esso bulk dealer and take it with you or the remainder of it after fresh oil change.  For summer time you can skip the 10W or 15W stuff.  Also exact same stuff found at Crappy Tire in their brand "Motomaster" if you run short.

I would go the Esso bulk dealer and get the XD-3  0W-30 and run the whole trip on a fresh change.

[barrie1]

DEpending on the milage on your sparkplugs I would also possibly throw a new set into this engine as the Best GM ones will pay for themselves in fuel savings over the life of the trip and the truck as well. They are warrantied for at least 160,000 klms from the factory to start so they do burn hot an very effecient as well. 

[ilovecables]

Would installing a CAI (cold air intake) be of any benefit?

[barrie1]

A lot of the racers do that as it does increase the HP of the engine that runs it. 

[ilovecables]

So, that's prolly a better bet that getting an OEM replacement......
Any idea how much they are?

[rrocket]

If you are worried about the oil, get an AEM Dry Flow filter...no oil and filters as good as any other filter. AEM does make a filter for your truck too by the way.   Otherwise a K&N will work fine. Or an Air Hog.  I've used these gauze type filters since I was old enough to drive and NEVER a worry with the MAF being oiled.  Shrugs.  And yes, fuel mileage has always increased when I've used these.

[PJungnitsch]

An independent test of K&N vs dry and foam air filters here:

Overall:

http://www.bobistheoilguy.com/airfilter/airtest1.htm

Details of the flow test:

http://www.bobistheoilguy.com/airfilter/airtest2.htm

Details of the filtration test:

http://www.bobistheoilguy.com/airfilter/airtest3.htm

[rrocket]

FWIW, I replaced my K&N with AEM Dry Flow after seeing a detailed analysis between the two by an independant lab. (That and the Supra guys are loving these things)

http://www.aempower.com/files/swri_dff_test_data_10-7.pdf

[articsteve]

An independent test of K&N vs dry and foam air filters here:

Overall:

http://www.bobistheoilguy.com/airfilter/airtest1.htm

Details of the flow test:

http://www.bobistheoilguy.com/airfilter/airtest2.htm

Details of the filtration test:

http://www.bobistheoilguy.com/airfilter/airtest3.htm

   interesting read

[barrie1]

I have a large K&N filter hung up in the shop as I have gone back to a paper cartridge type in the truck. It seems to be lasting much longer wihout needing the service the K&N did. Certainly cheaper to run as well for only $10.00 as well. 

[shawcross]

go with green air filter it breaths better and i would agree that the oil from performance air filter would damage the mass flow sensor