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So I have had K&N filters in all my cars for a while now with no complaints until now, Installed one on my 08 TL-S, and it turned it into a complete turd. I could not believe how much power I had lost, immediately reinstalled the stock filter and bam... power restored. I'm going with all OEM, hell with it, I'm not building the car or anything like that. So stock it will stay. Now to sell this filter...lol.
You mean you didn’t get the extra 15 horsepower and torque that K&N claims? Wow, I would be pretty pissed. I can think of a few things that could have caused this. Did you over oil the filter? Did you leave the plastic bag on the filter? OK, I know this sounds silly, but it has happened. K&N’s traditional high-flow air filters are designed with 4-6 layers of cotton gauze pleated between coated wire screen mesh. K&N filters do need to be cleaned by using what they call a recharger kit. Often people will use soap and water or even run them through the dishwasher for cleaning. Most K&N filters come pre-oiled from the factory with the exact amount of oil applied. I would think that your filter is clogged. Did you purchase it used? Did you use a different oil than K&N to lube the filter? Of course it is possible that this filter is defective and if so, you should probably return it for another one or get your money back. Perhaps this was a good learning experience and you might consider returning to an OEM filter that will cost much less and do a better job filtering.
So I have had K&N filters in all my cars for a while now with no complaints until now, Installed one on my 08 TL-S, and it turned it into a complete turd. I could not believe how much power I had lost, immediately reinstalled the stock filter and bam... power restored. I'm going with all OEM, hell with it, I'm not building the car or anything like that. So stock it will stay. Now to sell this filter...lol.
Put the OEM filter back in, all K&N filters do is allow MUCH more dirty air into the engine.
I was curious about the K&N filters myself so I found this online. I know all filters are different and depending on shape and size one brand can be better for a certain car but just seeing these results are kind of crazy to see. K&N Air Filter Review - Debunking the Myths (and why OEM is better)
Yeah There is zero power to be gain. I installed a Cold air intake on my car for the sound
and it actually felt slower at low RPMS.
It does sound Amazing so that's that lol
I was curious about the K&N filters myself so I found this online. I know all filters are different and depending on shape and size one brand can be better for a certain car but just seeing these results are kind of crazy to see. K&N Air Filter Review - Debunking the Myths (and why OEM is better)
*Covers Ears*
LALALALALALALALA
I just ordered a K&N for my (new to me) 08 Type S... I pulled the paper filter this weekend and saw it was HORRIBLY dirty (caked with leaves, dead bugs, dirt, etc). I looked for a regular paper filter locally and found they're ~$30, so I figured I'd "upgrade" to a K&N for $56. I've been running K&Ns (and other similar filters on CAIs) for years in my other vehicles and never had a problem... but I had never actually seen a scientific study on them. I never expect much performance gain from them, but I like the subtle sound difference, and figured (maybe incorrectly) that they filtered well.
On a related note... I shook the big stuff off the old filter before putting it back in (while I wait for my new one), and can already hear a difference. So I guess realistically... a clean filter is probably more important than the type.
I just ordered a K&N for my (new to me) 08 Type S... I pulled the paper filter this weekend and saw it was HORRIBLY dirty (caked with leaves, dead bugs, dirt, etc). I looked for a regular paper filter locally and found they're ~$30, so I figured I'd "upgrade" to a K&N for $56. I've been running K&Ns (and other similar filters on CAIs) for years in my other vehicles and never had a problem... but I had never actually seen a scientific study on them. I never expect much performance gain from them, but I like the subtle sound difference, and figured (maybe incorrectly) that they filtered well.
On a related note... I shook the big stuff off the old filter before putting it back in (while I wait for my new one), and can already hear a difference. So I guess realistically... a clean filter is probably more important than the type.
Pat
Disclaimer, every time I post this I get flamed, but here goes anyway...
The truth is, a dirty air filter filters better than a clean one (at a very-very slight cost in power, but with an even slighter improvement in fuel economy):
That makes sense... a completely clogged filter isn't gonna let any dirt through. If you want a really good filter, just put a rubber plug on the intake.
I only briefly skimmed that document, but it sounds like it's quite a bit more than "very-very slight cost in power" ("The simulated clogged filter significantly affected vehicle performance, increasing the time to accelerate from 20 to 80 mph by 0.6 to 1.7 seconds on the three vehicles")... it sounds like the fuel economy is okay because the closed loop control can reduce fuel to keep the AFR correct. But that's causing a reduction in power, and probably also causing a slight increase in fuel economy (by making you accelerate slower... you get better gas mileage if you don't stomp it at every green light ).
Disclaimer, every time I post this I get flamed, but here goes anyway...
The truth is, a dirty air filter filters better than a clean one (at a very-very slight cost in power, but with an even slighter improvement in fuel economy):
I’ll be happy to be the first to step up to flame. There is one test for air filters. It’s an absolute test to test any air filter. It is called the ISO 5011test.
If you want to test your Purolator, Baldwin, AC, K&N, or AMSOIL air filters it will cost you about $1700 per filter, to send them in and have them tested. For that price you would have real data about your filter.
These ISO 5011 machines cost upwards near $300,000.00.The ISO 5011 standard (formerly SAE J726) defines a precise filter test using precision measurements under controlled conditions. Temperature & humidity of the test dust and air used in the test are strictly monitored and controlled. To obtain an accurate measure of filter efficiency, it’s very critical to know exactly the amount and size of test dust being fed into the filter during the test. By following the ISO 5011 standards, a filter tested in England can be directly compared to another filter tested in California.
The ISO 5011 filter data for each filter is contained in two test reports. Capacity Efficiency and flow restriction.In looking through the test results you listed, I did not see even one reference to the ISO 5011 or SAE J726. I would reject this study just on that basis along. Instead of using this standard air filter test machine, they use a Baldwin $29 vacuum tester. Not quite the same thing.
Just so you know, the result for testing the above 5 filters had the AC Delco in first place with the K&N last.
250K miles here with a K&N. Still get 30 MPG on summer gas going down the highway, still only burns 1/2 quart between 7500 mile oil change intervals. Throttle bottle and downwind side of the air box are spotless.
Does a K&N give you any extra power? Not likely.
Does a K&N ruin your engine? Not for me.
Disclaimer, every time I post this I get flamed, but here goes anyway...
The truth is, a dirty air filter filters better than a clean one (at a very-very slight cost in power, but with an even slighter improvement in fuel economy):
That's the case with HEPA filters anyway. I validate cleanrooms and it's a known fact that particulate matter levels decrease as the filter becomes "dirtier". HEPA's in cleanrooms don't typically become saturated since they're normally on a pretty conservative maintenance schedule and there's usually a prefilter. But the idea might be the same between HEPA's and standard auto filters. Essentially the more crap you get in the filter, the less likely additional crap is to pass through since it's blocked by both the filter media and the existing particulate. Assuming there's enough surface area to allow sufficient air to pass without excessive leeching of power from the engine, an older filter may actually be better in a way. Most filters won't allow more material to pass as they get dirtier. They'll simply let less air through.
Not saying you shouldn't change your filter of course. Once it starts leeching power from the motor and/or becomes totally saturated it's not going to be a good thing.
That's the case with HEPA filters anyway. I validate cleanrooms and it's a known fact that particulate matter levels decrease as the filter becomes "dirtier". HEPA's in cleanrooms don't typically become saturated since they're normally on a pretty conservative maintenance schedule and there's usually a prefilter. But the idea might be the same between HEPA's and standard auto filters. Essentially the more crap you get in the filter, the less likely additional crap is to pass through since it's blocked by both the filter media and the existing particulate. Assuming there's enough surface area to allow sufficient air to pass without excessive leeching of power from the engine, an older filter may actually be better in a way. Most filters won't allow more material to pass as they get dirtier. They'll simply let less air through.
Not saying you shouldn't change your filter of course. Once it starts leeching power from the motor and/or becomes totally saturated it's not going to be a good thing.
Exactly my point; thanks.
As for replacing air filters in my cars, up here in New England we don't get much dust, and we only have typically six to eight weeks of pollen; I've found even 80,000 miles isn't enough to cause any discernible loss in performance.
To me the type of filter doesn't matter, swapping a stock filter for a k&n one won't do anything. the difference is if you install a cold air intake. I noticed a difference when I installed mine, that was the first thing I did when I got the car. I love the sound now.
To me the type of filter doesn't matter, swapping a stock filter for a k&n one won't do anything. the difference is if you install a cold air intake. I noticed a difference when I installed mine, that was the first thing I did when I got the car. I love the sound now.
There are a few differences; K&N filters are notorious for letting in huge quantities of dirt (which shows up in Used Oil Analysis reports as silicone/sand) into the engine. As for adding an aftermarket CAI (you do know the factory intake is already a CAI, right?), the only real difference you'll experience is noise.
Thank you for schooling me. I guess the extra noise made me think it was a little faster lol. It didn't even occur to me the stock setup already being cai when I was removing it.
There are a few differences; K&N filters are notorious for letting in huge quantities of dirt (which shows up in Used Oil Analysis reports as silicone/sand) into the engine.....
Totally bogus. I have numerous UOA's run with the K&N and my Si levels were, without exception, at or below baseline. And I live on a dirt road.....
Last edited by nfnsquared; 07-08-2017 at 03:28 AM.
Totally bogus. I have numerous UOA's run with the K&N and my Si levels were, without exception, at or below baseline. And I live on a dirt road.....
We're going to have to agree to disagree; go over to BobIsTheOilGuy.com and look in the UOA database, it is very obvious which cars have a K&N and which do not.
Put 2 or 3 dabs of grease downstream between the K&N filter and throttle body. Then go drive the car for 3 or 4 weeks. Then go check those dabs of grease. You will find that each dab of grease are full of grit. Grit that would have gone through and into your engine. It’s not just the Corvette forum, but many forums. The last K&N filter I saw come into the shop, I just held it up to a bright light and could easily see small spots in the filter where I could see the light. If light can get through, so can dirt. I realize that investing in a K&N filter is expensive; you have the filter, cleaning kit, recharger kit etc. I also realize that we all want to believe that we can get 15 or 20 horsepower more just by changing the air filter and certainly like the added noise from using a K&N filter. All engines can digest a certainly amount of grit, but at some point, they will stop.
The Corvette forum does not recommend K&N filters...
More .
One person made an unsubstantiated claim (which was later debunked in post#108, linked below) and you post that totally false statement? Really?
I guess you missed all the posts from Corvette board members saying they've run K&N for 10's of thousands of miles with no issues. And let's not forget the posters who have done UOA's that show no increase in Si when running a K&N. How about the link to the guy who ran a K&N for 1,000,000 miles on his truck?
I don't give a damn what filter you run, but don't post
I have been walking around with gauze pads soaked in mineral oil up my nose but after reading these posts I have now decided to use just plain Kleenex. I can,t walk as fast and it's harder to breathe but I think now I will never die .
Last edited by nfnsquared; 07-08-2017 at 04:46 PM.
As I mentioned, on BITOG there are literally hundreds, probably thousands, of UOAs posted over the years which show high sand/silicone from running a K&N filter. I just logged into that site for the first time in years and in a space of about five minutes I can up with a few dozen reports, the image of one such is below.
Funny thing, I've never really noticed it before, but probably a third of the reports I read with K&N filters and high sand findings were Honda/Acura products. I rather doubt Honda's are more prone to ingesting sand than other cars; maybe more folks put K&Ns on their Hondas than other brands.
Regarding your tone; I know you generally write with an abrasive attitude when you don't like or don't believe what someone else wrote, but I really don't appreciate it. I recommend you ramp back your rhetoric a bit.
As I mentioned, on BITOG there are literally hundreds, probably thousands, of UOAs posted over the years which show high sand/silicone from running a K&N filter. I just logged into that site for the first time in years and in a space of about five minutes I can up with a few dozen reports, the image of one such is below.
Funny thing, I've never really noticed it before, but probably a third of the reports I read with K&N filters and high sand findings were Honda/Acura products. I rather doubt Honda's are more prone to ingesting sand than other cars; maybe more folks put K&Ns on their Hondas than other brands.
Regarding your tone; I know you generally write with an abrasive attitude when you don't like or don't believe what someone else wrote, but I really don't appreciate it. I recommend you ramp back your rhetoric a bit.
What rhetoric?
Link to the thread where that UOA was posted?
If you'd like to know how many millions of germs are on your hands even after you wash it profusely with soap, you would chop your hands off. So I'll leave the filter in. Almost 11 years on this Accord V6 with 260000 miles with zero issue. 200k miles on a previous 98 Accord V6 wit K&N filter. So I correct my previous figure, that I actually have driven on K&N filters for 460000 miles. I'm also an engineer but I'm not going to be scared of life.
^^^^ What? Are you crazy? Didn't you see the unattributed UOA posted by crazyhorseshoes? Your engines are going to explode!! Good God, man, what are you thinking?
I'm not a big fan of K&N filters either. Had one many years back and didn't notice any differences in MPG/responsiveness. When you hold it up to the light, you can clearly see the holes in the cotton mesh, which mean less filtering efficiency. Yes, it's oiled, but that's not enough to make up the difference. Will it negatively impact the engine over the long haul? Probably not unless you live in a super sandy/dusty area, but for me, I just use Wix filter and call it a day.
06-25-2017, 03:54 AM
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