C
coaster
i am considering one for 2005 Forester ... are these air filters worth the
money?
money?
Hi,AS said:Well, after asking my question decided to surf the web and found one
test made by someone that understands what all of it is about.
http://www.bobistheoilguy.com/airfilter/airtest3.htm
I am sure a car would perform much better, if just for a while, without
the restriction that and air filter imposes, but to me, not in the
racing high performance circle, the air filter function is to protect
the engine.
Good Luck!
coaster said:i am considering one for 2005 Forester ... are these air filters worth the
money?
coaster said:i am considering one for 2005 Forester ... are these air filters worth the
money?
Tony Hwang said:Hi,
I use foam filter impregnated with oil. Wash it every two years.
When I see all the fine dirt the filter caught, I know it's doing the job.
Wash, clean it, spray very very thin layer of oil, wipe off excess
put it back, use it over and over. My reason is economy rather than using
throw away type paper filter. I don't race.
I've had one, and found it to be too much work.
Bonehenge (B A R R Y) said:Those willing to the work may save a few bucks over the long run, but
it is a lot of work.
Performance wise?
Looking at K&N's own graphs, most foam filter gains are at very high
RPM's, ~ 5000 RPM, nowhere near the 1500-3000 RPMs that most cars see
in normal driving. Even up the high range, the gains are at most a
few horses and not something all that noticeable.
On K&N's own published FAQ, they no longer claim a mileage increase,
only that "some customers have reported gains". I'd bet those folks
went from a dirty paper filter to a clean K&N. Similar gas mileage
gains probably would have been seen with a clean paper filter. I
think is was last year that the gov't clamped down on unsubstantiated
mileage claims in advertising.
On a fully prepared race car, with all kinds of mods that add a few HP
each, they all add up, so a K&N is probably useful. On a street car,
the biggest K&N performance gain will probably be from the decal or
the visual impact under the hood of a show car. <G>
Hi,coaster said:what oil do you spray on the filter? is this after you washed with water?
thanks!
Tony said:Hi,
The filter came with a spray can of oil. I think K&N has it too.
Yes I wash it in warm water.
BTW, this filter kit is from Amsoil.
The trick is using oil very little. If it goes thru foam, there is a
risk it can screw up MAP sensor. I wash filter in summer time and dry it
well under hot sun, then spray oil very thinly on the foam intake side.
Squeeze it between newspaper sheets to soak up any excess oil.
Need to do this every other year for normal driving.
Using this since car was new and did not have any trouble.
Those willing to the work may save a few bucks over the long run, but
it is a lot of work.
Performance wise?
Looking at K&N's own graphs, most foam filter gains are at very high
RPM's, ~ 5000 RPM, nowhere near the 1500-3000 RPMs that most cars see
in normal driving. Even up the high range, the gains are at most a
few horses and not something all that noticeable.
On K&N's own published FAQ, they no longer claim a mileage increase,
only that "some customers have reported gains". I'd bet those folks
went from a dirty paper filter to a clean K&N. Similar gas mileage
gains probably would have been seen with a clean paper filter. I
think is was last year that the gov't clamped down on unsubstantiated
mileage claims in advertising.
We can debate performance gains but the cost savings of cleaning make
it worthwhile
Ditto!The difference is the change in engines.
Years ago, with carbs and first generation EFI, a blocked filter made
the engine run progressively richer as it plugged up.
With OBD2, in particular, this is no longer the case. The computer
adjusts the fuel to the amount of air available, keeping the mixture
more or less constant - so on today's engines a free flowing filter
does NOT affect fuel mileage. It CAN affect power output, but
generally only at high RPM when the engine air demand exceeds the
capability of the filter to supply it.
We can debate performance gains but the cost savings of cleaning make
it worthwhile
The difference is the change in engines.
Years ago, with carbs and first generation EFI, a blocked filter made
the engine run progressively richer as it plugged up.
With OBD2, in particular, this is no longer the case. The computer
adjusts the fuel to the amount of air available, keeping the mixture
more or less constant - so on today's engines a free flowing filter
does NOT affect fuel mileage. It CAN affect power output, but
generally only at high RPM when the engine air demand exceeds the
capability of the filter to supply it.
Hi,StephenW said:I agree on the OBD tuning, but disagree on the cost savings. I feel, and is
supported by the web page I posted, that the k&n lets too much dirt through.
You may save money in the filters, but think it isn't worth it to the life
of the engine.
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.