Quote:
Originally Posted by Snkypete
About as good as your engineering study that it allows more dirt into the engine? That is probably the oldest myth and the most laughable.
Bottom line, you simply cannot "feel" a difference of under 10whp when sitting in a car - just the facts of it. The only way to tell gains in that range is by actual testing.
That being said, I did a before/after dyno yesterday on my bone stock 08 335xi AT and saw zero noticeable gain from the K&N...there were slight gains of 2whp here/there but overall it was flat. I've had reusable filters on every vehicle I have owned for years and this is the first one where I didn't see an increase of at least 5whp.
I know a DCI would provide a definitive increase, but for personal reasons it wasn't the road I wanted to go.
|
The Spicer test a Myth? Really? You should really support that statement.
If you think a less restrictive filter (cone or otherwise) does not allow more dirt into your engine you need to put down the cool-aid. More air flow translates into less restriction. Basically, you have two factors when determining filter performance, filtration and dirt holding capacity. Filtration has several parts - pore size, porosity, depth, etc. Dirt holding capacity is largely a function of surface area of the filter.
K&N filters are very porous, with very poor control of the pore size. They will initially pass lots of air with low pressure drop, and assuming it is oiled properly will initially give good filtration, not as good as OEM though. The problem with them is that they have very little dirt holding capacity. They load up very quickly and then have higher pressure drop than OEM filters (i.e., pass less air at a given pressure drop).
Here is how one can uncover the lie about these so called performance filters.
Test your car with a new stock filter.
Next next test your car with no filter.
The delta between the two is the maximum theoretical gain any filter can provide - for most cars that is a 1% to 2% gain.