An interesting read....

http://www.shipkiller.com/Debunking_...is_Better.html

 

I didn't see a date on that test report, but I thought the K&N myth was busted years (decades?) ago. As I recall, I read a report about the K&N air filter allowing more fine particles through first, and later read another report that the OE air filters of most cars provide all the air that the stock set-ups would take in anyway.

Modified breathing systems can benefit from more air intake, assuming the optimum amount of additional fuel gets into the mix as well. In that case, I don't think internal engine modifications are necessary for a modest gain in power.

Anyway, I removed the K&N from one car, but kept it in my track/autocross car, which had breathing modifications and a performance chip mapped for those changes. I never had a clue as to the effect the K&N actually had, except it was more labor intensive to properly clean and re-oil the K&N than it was to simply install a new OE filter. I sold the track/autocross car years ago, so I've been K&N free for almost 7 years.

 

Sadly, most people will trust the "up to 15% proven horsepower gain!" advertising line, then they will trust their own logic. I've always said that if a filter can make a difference, go around the block with no filter at all, and tell me how much seat of the pants power you feel.

 

So in a test for a GM engine an ACDelco filter destroyed the competition in every category.

Hmmm, interesting.

 

This once again confirms what I have been preaching & practicing for a long time. My test equipment - common sense and butt meter.

 

///Matthew: I noticed that part too. Another way of saying it is that the ACDelco was the "most restrictive" air filter in the test.

 

No. You are misinterpreting the data the author provided.

The AC Delco was the best at fliltering particles, but had the worst airflow.

The K&N was the worst at filtering particles, but had the best airflow.

It's a trade off, a design compromise.

Notice that these tests were done on air filters for a Diesel engine. Diesel engines do not require nearly as much air flow for air intake as petrol engines do, so the flow requirements are lower for Diesel air filters than for an air filter for a petrol engine of the same displacement.


Also notice that there are no power tests support up the author's impossibly broad and plainly absurd claims that "The stock filter will flow MORE THAN ENOUGH AIR to give you ALL THE HORSEPOWER the engine has to give." This statement is possibly true for some vehicles (especially diesel ones). But it's certainly not true for all vehicles, and it's likely not true for most vehicles.

For example, in a prior life, I owned a Honda Prelude. It had a high-revving 2.2l VTEC engine. I dynoed that car bone stock, then replaced the factory air filter with a K&N in the stock airbox and dynoed again. It made 4 more HP and lb.ft, an increase of only about 2.5%, but an increase nonetheless thanks to the additional airflow at higher RPM.

 

Quote:
I read the post by "Matthew" as throwing in a bit of sarcasm, poking fun at the test results...I could be wrong tho...
..some of these threads are so funny...debates about filtering mechanisms

 

It is true. I was being sarcastic. Or more accurately...normal.