http://www.nicoclub.com/archives/kn-vs-oem-filter.html


Great article with a great insight

 

interesting..

 

Very nice. It backs up what I've been trying to tell people for years. K&Ns are good for keeping rocks and birds out, that's about it. They load up quicker as well. The stock filters cause no restriction so a higher flowing filter can not increase power if the stock one does not present a restriction in the first place. The stockish filters as they load up have a more linear air restriction while the K&N's flow goes down quickly.

The Amsoil filter in that test is the old series, not the awesome EAO filters.

This is why I use OEM Acura filters. They filter the best, they have a silicone seal that won't fall apart, and that style of filter flters better as it gets dirty unlike the K&N. It doesn't pose a restriction to my engine so why would I go with a higher flowing filter that will do nothing but let considerably more dirt in and cause cylinder and ring wear as well as dirty oil.

Some will say "my car has gone 500,000 miles with a K&N" and some cars in some areas hardly need an air filter but if you live in a dusty area like I do, the air filter is the most important filter on the vehicle as far as engine life is concerned. Look at the quality of the OEM Honda filters, they obviously thought it was of high importance considering it made it past the penny pinchers.

And before anyone says it, it is 100% impossible for an air filter no matter how restrictive or free flowing to affect your mpg, a restrictive filter can only affect your full throttle power.

Good thread.

 

nice find on this topic. makes me want to swap out my AFe drop in filter for the factory one

 

i agree with zach, i JUST threw out my OEM one.. i was like "ill never use this shit again" but looking at the facts i feel like a idiot for tossing it.

 

Just to clarify so I don't mislead anyone, the stock filter is no restriction when the engine is stock and with basic bolt ons. Obviously a turbo or supercharged TL will lose power from a stock filter. Most OEM filters are sufficiently oversized so you don't lose power as they get dirty from normal use and no OEM is going to leave power on the table in the form of a filter after hundreds of thousands of dollars in R&D in the engine, extracting as much power as they reasonably can and then leave power behind because of a piece of $.10 paper was too small when it costs them practically zero money to make it flow better.

There were examples of this back in the old days when you could gain 50hp from a filter and exhaust with a 7.0L blowing through a single 1.25" exhaust but these days they do a great job of extracting as much power as possible.

 

Very true. However I wish they would have made a better jpipe, cats and most of all exhaust manifold. If they put a legit exhaust manifold on there they could gain some good power and I would assume gain a little mpg.

 

^^ at the cost of emissions and additional parts so thats not gonna happen

 

Yeah, they're pretty much stuck with the cats. The bend from the heads to the cat could've been a little nicer but not a lot to gain without getting rid of the converter.

The heads seem to flow extremely well as is, even with the exhaust merged inside of the head. It's done to keep as much heat in the exhaust as possible for quick cat lightoff. A shorter exhaust path and no surface area for it to cool before reaching the cat helps a lot in lightoff time.

The only real solution for Acura to free up the exhaust while retaining the same emissions standards is to add another couple cats in parallel which isn't going to happen.

 

True. I, personally am perfectly fine with them dropping the ultra low emissions to gain some power and maybe a mpg. However 95% of the people buying them want what I don't. Such is life.

 

I agree, I would take more power any day. It is nice though, when I'm in my garage and tuning the stereo with the engine running and there's no smell at all. I've actually heated the garage up to over 100 degrees on a 40 degree night because I left the engine on too long. I don't recommend it but many other cars would've killed me.

The gains would basically be the same as the high flow cats, and I have no idea what kind of gains we get with those.

 

What a great read, thanks for sharing! I've been a victim to marketing as I would have never guessed that it's actually worse at filtering. At least I'm still running an OEM filter.

I have to call my friends and warn them!!!

 

Yep. I've seen inside intake manifolds and the ones with stock filters are cleaner.

 

for those running custom 3-4" CAI, I feel that the AEM dry flow filters better than a K&N. I look at the dust/dirt collected on my IAT sensor and it was cleaner on the AEM after the same amount of milage on both types filters.

 

 

Very interesting article

 

I guess I never put much thought into it, but I just always assumed people bought K&N's and the cleaning/oil kit with the sole intention of saving money over the long haul. I find it laughable people actually think they're gaining power and mileage with one.


I also wish they'd kept a conventional head design so we could run headers, but I'm actually glad they left some power on the table in other areas. It wouldn't be quite as fun if they were all tapped out from the factory, since FI would be the sole option for increasing power.