Aftermarket Panel Filters. A word of warning

[ReubenH]

Hey there. After having removed my engine this weekend and fixing up the odd little oil leak here and there, and changing back to my VF39... i found that the turbo was indeed damaged. All along the leading edges of the compressor blades there were little nicks and chips. Very very small ones, but left unchecked, whatever was causing this could have done more damage.... Much more damage. I looked in the intake pipe, and it was caked in crap, it was like a coarse sand paper there was so much shit in there. It turns out my HKS panel filter has done it's dash. It came with the car, and in the last few months has basically started to brake down and die. A friend of mine bought a nuked BC that had one of these HKS filters in it, it had a hole in it. Turns out it disintegrated and was sent through the whole engine!

So yeah, this is the last straw for me, i'm not going to touch anything but genuine filters. I thought i was fine cause it was a foam filter, not oiled, and not a poddie. But no, even then they can cause shit to die.

[Guest boostin]

Ooooh bugger. I had one of those stainless pods on for a while. It got binned after I found dust stuck to the fine coating of oil from the breathers in the intake pipe.

[ReubenH]

Yeah. Bugger eh. I even cleaned mine periodically. I last cleaned it about 10,000K/6 months ago, and i noted no dust in the intake then (wasn't looking for it though).

Oh, the whine on boost has been fixed it would appear. One of the intercooler gaskets was fucked, and the screws weren't even tight on it. New gaskets, and the VF39 back in, and it goes hard. Even with little nicks on the compressor blades... I have my eye on the turbo though, now that i know what damage has been done to it. Still, the TD04 i bought was in similar condition, if not a little better off (even though it probably was 100,000k's older than the 39)

[subieboy]

Sheehs some people never learn

How many threads have there been over the years on after market filters (including poddies) and how useless they are??? I mean really

Its been proven time and again, by real independent testers and not some tosser paid by any of the manufacturers such as KnN, that factory paper filters flow better and stop more crud.

Period

see www.autospeed.com.au for confirmation.

 

Other potential problems are:

* Cost (a brand name filter can often cost a couple of hundred dollars)

* A rougher idle (the flow through the airflow meter can get disrupted)

* Airflow meter damage (the oil from the filter can be deposited on the hot wire)

* Noise (induction roar can be excessive)

* Effectiveness of cleaning (a washable air filter is often viewed as a plus, but getting it to maintain its filtration and flow performance after it's been cleaned is problematical, in fact look below...)

* Unknown filtration quality

We should point out the abovementioned filtering problem can be major. You can be certain car manufacturers extensively test the dust filtration effectiveness of their standard air filter; who knows how effective the filtration of an aftermarket product is? The chances are that if it flows better, it lets bigger particles through to the engine. For this reason, it's dangerous to pay attention to 'filter tests' that have been performed solely on a dyno - the filter that makes the best power is unlikely to be the best filter overall.

Don't be completely put off, though - pod filter installations can be quite effective when installed intelligently.

[Guest SPANKU]

ive owned turbo cars for like over 16 years now. i never had any problem with any pods or k&n filters

my poddie in my car started to collected some rust on it so i think its time for a change. i am going back to factory for now until i can afford a Apexi one

[Guest boostin]

For my impending swap to a V3 ECU with an orange AFM I have to run a pod as no factory air box will fit. I got an Apexi pod for this as from everything I've read, they have the best filtering and flow specs (bar the factory panel filter). I got it from Redline for around $120. Pretty cheap I say. No adapter needed either as it bolts directly to the AFM.

[driftrex]

foam filter? well yea they do break down they dont last forever just because they are washable. how old was it?

btw i have had foam ones in cars through work that have done the same thing and had holes in them, people dont relise they still need to be replaced like a normal paper filter.

[nt_a_foz]

 driftrex said:

foam filter? well yea they do break down they dont last forever just because they are washable. how old was it?

btw i have had foam ones in cars through work that have done the same thing and had holes in them, people dont relise they still need to be replaced like a normal paper filter.

Exactly it sounds like tahts reubens problems its friggin old..What do you expecti t to last forever??

If it was in there when you got the car prob (a year and a half ago iirc) and had been in there a while befoore then yeah no wonder....

[Guest boostcut]

haha cry me a river...lol you car enthusiasts should have maintained your gear better

[predator]

I've used K&N for 12 years or more and never had a problem. I maintained it and cleaned it regularly and never replaced it or had any issues with it.

[driftrex]

 boostcut said:

haha cry me a river...lol you car enthusiasts should have maintained your gear better

lol exactly.

[Guest]

It's nothing new aftermkt filters don't filter as well as factory

[Guest SPANKU]

there are better filtering but what about the flow?

[Guest]

 

Now my FMIC pipework was made so I could keep the stock airbox. I run a stock airbox with 100mm PVC feeding the airbox, and 3inch to 2.5inch stainless finally to a 2.25" silicon onto turbo inlet. I use a stock Subaru paper filer in my air box. I have no air flow meter, as it is MAP tuned.

I tuned my car on the Haltech dyno to 240kW ATW at 17.5psi boost. This is excellent power for the boost level, but I had it in my mind that the stock air box and air filter would be reducing the output, so when I finished tuning, I did a few final runs that were very consistent over the top of each other to 240kw ATW. I then removed my airbox, and as much of the intake as I could easily remove in a couple of minutes so the turbo was being fed by a silicon joiner with 6 inches of stainless pipe. I then did several runs, and other than the usual loss of low down power on the first run due to low header temps, the following runs were identical to those done with the airbox and intake in place.

My conclusions are:

* The stock airbox and air filter are better than people generally accept, and are probably as good as any other solution at the power levels most people are likely to run.

* There is alot of crap in the air filter industry. Claims of power increases due to air filters seem quite rediculous.

* If a stock air filter can flow as good the engine with the air filter and air box removed, there is no way a pod could make any more power than a stock air filter.

Of course I did not test the stock air box with stock resonator and intake to turbo pipework, which may be a loss of power... I am purely talking about the box and airfilter.

i have done a similar test with similar results

I have tried a pod - apart from the laughable intake noise i notice no difference in performance

[predator]

Yeah the claim of power gains isn't accurate. I read a magazine recently that did a test on filters, can't remember the car, but the best they got was just over 3KWs. Tested different brands on the same car running on a dyno. No surprise really. It's one of those mods that we think "MUST WORK" just cos we paid biggish $$$$'s for them over std.

[aim]

Lol this just shows how little I know! If pods really aren't good for the engine (worst at filtering) and only provide an extra ~3kw, why are they so common?

[dubbedup]

intake noise.

[Koom]

Cause you can clean them rather than replace, girls go all gooey when they hear that you have a pod filter, blingo and noise.

That and alot of people follow the pre-conceived notion that they must make at least 12 more kw jsut cause they exist.

[Guest]

Most FMIC kits force you to remove the airbox so then some sort of pod filter is needed

[predator]

I had a mate who put a serious exhaust system on his car. He was convinced it would give huge power gains but when he dropped it on the dyno it showed 7KWs. He told me years later that the roar of the exhaust made him think the car was going faster ;D so it must be producing heaps more

[Guest SPANKU]

yes thats the other idea is that it make you think your car is faster

[aim]

So whats the most cost efffective way to get power gains? Or is "new car/engine"

[predator]

NOS! ;D

Well if you've seen the Fast and the Furious you'll believe it

[Hailz]

Ive had a K&N pannel in my GTB for 20,000kms, my mate has had one in his for around 80,000kms and niether of us have had any problems at all, no airflow meter probs and no dust at all getting past the filter and resting in the intake pipe, both have been cleaned about every 10,000kms, and I am dam sure they make a diference in peformance!! My mates Legacy has done just on 190,000kms on the original engine - and no thats not a missprint! I think if a problem was going to arrise from using a K&N it would have by now, I plan on using a K&N pannel in all of my future cars, I cant see how they can be such a bad thing, hundreds of thousands of cars worldwide use them.

My 2 cents worth on the matter.

[predator]

I still use a K&N panel filter. Not gonna change my mind.