K&N panel filter + stock tune = bad?

[SCHM1AN]

I don't have the ability to log anything, but if you could kindly point me to some of your data claiming knock is present, I would be glad to look at it and form an opinion for myself

[seabass07]

My logs are not organized, so I can't point you to it. If you don't have the ability to log, then don't use a panel filter. It is known that the panel filters are dangerous on more aggressive tunes without scaling the maf. So if you use one on a stock tune without logging, you are just blindly assuming that everything is fine based on no data. That's dumb.

 

Btw, all you need is a $20 vagcom cable and a laptop.

[fahr_side]

Even some canned tunes, which are by default not aggressive, come with separate maps with different MAF scaling for stock filters vs. oiled panels.

 

frank_ster.... it is NOT the case that timing advances indefinitely until seeing knock. This is a myth and needs to be stamped out. There is a maximum timing value which is the base table plus knock correction advance plus or minus any compensations for temperatures. IAM at 1 and absence of FLKC puts the timing value at this maximum and it does not advance beyond that point. On a healthy engine this maximum should be a few degrees short of knock threshold.

Now, it is the case that some stock tunes do show knock at maximum timing, but this is an attempt on Subaru's part either to keep emissions or EGTs down, and some cars will show knock. The system itself is not designed to go looking for knock by pushing timing until it occurs. There's just no sense in that.

[ChemicalWaste]

I've been running a dump pipe and apexi pod filter for almost a year, a boost controller for around 9 months, and catback exhaust (so am now full turbo back) for 2 months and this is all on the stock tune. Touch wood have had no issues yet, but will be getting a tune once my turbo, fmic and associated mods go on in July/August

 

I would say all together I have done around 20,000 kms which is around 12,500 miles...

 

Flirting with issues. I'm guessing the dump pipe is a downpipe but you better get it tuned. That's a bit much for the stock tune i would think.

[Rome_STI]

It'll have to wait July/August as I can't justify spending the money now for a tune only to spend the same again in a month or two

[fahr_side]

Go price a shortblock and then think about that.

[ChemicalWaste]

how about just a stage 2 e-tune? It's $150 and that's a hell of a lot less than a new short block. I think that's pretty easy to justify. If you don't you stand a chance of blowing an engine. If you do you stand a chance of having it running properly. You also stand a chance of finding out that after driving at stage 2 with a stock tune you have already put an ass-whoopin' on your block. Regardless of FMIC and turbo hopes and dreams neither are going to be worth a pinch of doo-doo if you engine is out of service. Maybe it's different in Australia than the US models but I have no idea (it being the way the ECU manages things as well as the e-tune and pricing). I saw your Silver Surfer thread. Car looks sweet as hell. For the engine's sake though, get a tune.

[BAC5.2]

I really don't like these washable panel filters. Any filter that passes more air than stock is doing so because it filters less efficiently. The stock paper filter can support far more power than you can make on the stock turbo, so all you are doing is allowing more dirt to get on the MAF sensor, coat the throttle body and injectors, and get onto the cylinder walls. There is no performance gain to be had and as a money-saving effort it ranks up there with only changing your oil filter every second service.

 

IOW, fail.

 

I'm a little more neutral than that. I don't see the factory paper as an inherent bottleneck, and I don't believe that washable panels are any more or less flow restrictive.

 

Take the aFe Dry, for example. I made exactly the same power before and after the filter. Logs looked identical. No power was gained, no power lost.

 

What I did gain, however, is not having to replace a $10 filter every 10-12k miles (that's when I noticed the OE filters getting dirty to the point of impacting fuel economy). I spent $47 for a filter that is easily cleanable with compressed air. I'd wager the porosity is not much greater on the aFe dry than the OE paper, and I have actually noticed LESS dust on the inside of the airbox compared to the OE filter. It seems like I can get about 15-18k before fuel economy begins to drop and I need to blast it with shop-air to clean it out.

 

It's not REALLY a money saver, but it does turn a part replacement into maintenance. One less thing to buy every 3rd oil change, and one less item to keep in the garage on the shelf.

 

As for having an effect on the tune, no way. The stock tune can easily compensate for the minuscule, if any, flow difference. And Fahr is correct, there is absolutely NO situation where the factory ECU will advance to knock before pulling timing. I have seen, under some circumstances, where there will be an errant knock event and the ECU will continue to advance timing. But that's an exception, not the rule. It's also probably where people got the idea that the ECU advances until knock.

 

I don't like oiled elements out of principle. They rely primarily on the oil to trap contaminants. That's why they can flow more, the pores in the filtering media only have to prevent oil from penetrating so they can be much larger than a dry-type filter. That allows particulate flow that makes it past the oil film a nice, uninterrupted path through the filter. Over oil, and you blast your MAF with something that it's heating cycle won't be able to clean off. Oiled filters are simply not worth the time, and foam filters are kind of right up there. They provide no sufficient media to prevent intrusion of dust. Where something like an aFe Dry (and I guess that GREEN filter is similar) has progressively tighter layers, those foam filters simply maintain a consistent structure throughout. So if dirt and dust don't get stopped right away, the likelihood of them being stopped during their journey is slim, especially as vacuum increases through the filter. The further in they get, the less inclined they are to stop.

 

My $0.02.

[xt2005bonbon]

straight from the knfilters website FAQ. interesting..

 

 

24. More airflow means you are letting more dirt through, right?

 

No. Filtration testing measures the percentage of dust retained before the filter reaches a terminal test pressure, often 10" of restriction above initial restriction. We use airflow as a simplified term to explain a more complicated physical process. The more precise description is restriction: K&N air filters create less restriction which helps an engine run better. An engine will only use the air it needs and our air filters do not result in an engine using more air than necessary. Rather, they result in the engine experiencing less restriction. The terms airflow and restriction are inversely related. Our air filters provide either less restriction at a fixed airflow rate; or more airflow as a fixed level of restriction. In neither case is more air being used than necessary.

 

 

27. Will a K&N filter cause my vehicle's mass air sensor to fail?

 

No, it is both impossible and ridiculous.

 

It is impossible because we know that the oil treatment on our cotton is very small (usually less than 2 ounces). Once the oil is properly and evenly absorbed through the cotton, no oil will come off, even under extreme engine conditions. It is ridiculous, because no dealership or service provider has ever been able to provide us with evidence to support this "myth," and in fact, our investigations have revealed that even authorized dealerships are simply speculating and do not have the test equipment necessary to know whether the sensor has failed or why. It is even more ridiculous because some car manufacturers use and sell air filters treated with oil on a regular basis. There are also major brands of disposable air filters that are treated with oil. We all use oil for the same reason, it helps in the filtration efficiency of an air filter. For more information on this topic including videos, see our Mass Air Flow Sensor Statement page.

 

Out of the millions of air filters we sell, we only receive a handful of consumer complaints each month that a dealership or service provider has blamed a vehicle sensor repair on our product. We take each complaint very seriously and see it as an opportunity to stop a consumer from being taken advantage of. We investigate the situation thoroughly and take full responsibility for resolving the issue. For more information on how we educate and persuade the service provider to reconsider their position, see Mass Air Flow Sensor Information & Testing. We are so confident in our ability to resolve these situations and to help a consumer fight back that we offer our Consumer Protection Pledge.

 

As a result of our standing up for consumer rights and providing assistance to resolve a disagreement, we have had over 300 actual sensors sent to us by dealerships who claimed our product had caused them to fail. Microscopic, electronic and chemical testing revealed that none of the sensors were contaminated by K&N oil (K&N Detailed MAF Sensor Test Results). What is perhaps the single biggest clue to what is going on is that over 50% of these sensors were not broken in the first place for any reason. Click here for more information on how this may happen.

[BAC5.2]

You understand that K&N is trying to sell you something, so their input on those questions are significantly biased, right?

[xt2005bonbon]

You understand that K&N is trying to sell you something, so their input on those questions are significantly biased, right?

 

sure. To be fair, I believe it is important to hear what they have to say on the issue. On another note, I appreciate your input on your previous post.

[fahr_side]

You posted marketing blurb as fact? :D

[BAC5.2]

Manufacturers are out to make money. Their sales pitch should rarely taken as gospel.

[BarManBean]

I don't have the ability to log anything, but if you could kindly point me to some of your data claiming knock is present, I would be glad to look at it and form an opinion for myself

 

Here you go. Clearly some knock events occurring during the pull. Car was running on stock tune with only an aFe Pro Dry S filter installed.

 

The problem here though is that I don't know if this type of knock existed without the filter, so I don't there's zero cause/effect relationship here. I can't go back and test it either since I went stage 2 and am now tuned for everything following this logging.

 

 

EDIT: I might have a stock log on the computer at home, will have to check.

romraiderlog_20120402_191521.csv

[frank_ster]

Even some canned tunes, which are by default not aggressive, come with separate maps with different MAF scaling for stock filters vs. oiled panels.

 

frank_ster.... it is NOT the case that timing advances indefinitely until seeing knock. This is a myth and needs to be stamped out. There is a maximum timing value which is the base table plus knock correction advance plus or minus any compensations for temperatures. IAM at 1 and absence of FLKC puts the timing value at this maximum and it does not advance beyond that point. On a healthy engine this maximum should be a few degrees short of knock threshold.

Now, it is the case that some stock tunes do show knock at maximum timing, but this is an attempt on Subaru's part either to keep emissions or EGTs down, and some cars will show knock. The system itself is not designed to go looking for knock by pushing timing until it occurs. There's just no sense in that.

 

 

yes i know with iam at 1 it won't advance anymore than its set limits. but this depends on a million factors.

how good is the gas ? how well is the intercooler working ? since it doesn't even look at air temp entering the engine.

the differences between engines.

the differences between injectors.

etc..

 

the iam table is most effective at the cruse range. the system wants ro run as high as cylinder temperature as possible without knock. but yes as you said if the engine charastics allow for the iam to be at 1 it means the engine is not running as clean as it could be.

[Rome_STI]

Point taken but I'm not the only one in Aus who has run it this long without a tune with marginal long term side effects. It's not as if I sit on the pedal all the time, rarely if at all to be honest (for now). I've put it all in comparison and know that I won't really be able to test the car until it's been tuned.

 

Plus I look at things a little differently to what's been mentioned so far, if you look at my list of mods it isn't exactly on the low-side price wise so cost isn't an issue when it comes down to it...if I end up needing a new block it gives me an excuse to put something built in

 

EDIT: Sorry guys I don't meant to sound arrogant and blase about everything I know my car needs a tune, it is coming shortly, with all my extra goodies, and once I've done so you can check out the silver surfer page for some decent updates

 

EDIT #2: Also, we run 98 octane fuel here in Aus, but either way I am going to run a few logs in the next couple of weeks to test for any knock and report back

[ChemicalWaste]

It's your car. You do with it what you want.

[frank_ster]

 

EDIT #2: Also, we run 98 octane fuel here in Aus, but either way I am going to run a few logs in the next couple of weeks to test for any knock and report back

 

well your 98 octane fuel is probably like europs 98 octane which is measured diffrently which probably = 91 octane in northamerica.

[BAC5.2]

Australia reports only RON. So it's 98 RON. 98 RON fuels are typically 89 MON fuels, so that's ~93-94 by US standards (AKI; R+M/2).

[xt2005bonbon]

Australia reports only RON. So it's 98 RON. 98 RON fuels are typically 89 MON fuels, so that's ~93-94 by US standards (AKI; R+M/2).

 

that's about right. currently in France. using 'SP98' which is equivalent to 89–90 MON or 93–94 AKI. see http://en.wikipedia.org/wiki/Octane_rating

[Rome_STI]

So are premium fuels in US around 92-93 like that wiki page suggests?

 

Would there be a similar difference between E85 in US compared to AUS? Or do you guys call it something else?

[frank_ster]

e 85 is 85% ethanol. some people say its 105-110 octane.

 

we have we have cheap gas at 87 octane 89 is mid range 91 is high. there are some stations that have 92 , 93, and 94 and maybe a few others.

[Rome_STI]

Well we have E85 here, we don't have it readily available everywhere though hence why I'm not going down that route yet as my car is a daily...However Caltex here does some stupid seasonal blend with it and it's only 70% ethanol for 6 months then 85% for the other 6 months of the year.

 

We have 98RON available almost everywhere and my car's stock tune is for that fuel type so that's 93-94 in US? Our other choices are 91RON and 95RON and that stupid E10 crap which is 10% ethanol, I think it is 89RON but not sure

[Rome_STI]

Results are in! IAM is down and there is some fine tune knock correction going on, albeit minimal. I will be resetting my ECU today as I just realised I haven't done this yet since installing the CBE so will see if IAM gets back to where it should be. Either way tune is being booked within the next couple of weeks! Given it will be the first time my car has been tuned since ownership I'm pretty excited even if it is with stock turbo and tmic!

[SCHM1AN]

Go figure, I purchase a new paper filter and MAF cleaner and as soon as I leave Napa, my car starts running like it did before I put the K&N oil on