[njkayaker]

installed a K&N panel air filter yesterday. used them before on other cars and never had an issue.
did some data logging before and after.
Running Perrin Stage 1 93.
Was hitting mid to upper 17's for boost before.
After the K&N was hitting high 16's to 17.
i think once the ECU learns I'll be back in the mid 17's.
did not see any change in air\fuel ratio readings.
I don't expect any real performance gains. I just did it because the subaru stock filter is so expensive and this will be way cheaper for the life of the car.
i can hear the turbo sucking the air in when the turbo spools just a touch louder then a stock filter.

 

[Sotz]

before shifting to blitz cai, i used Pipercross dry filter. Very happy with it...

 

[monkiboy]

i have the HKS super hyrbid and really like it. perfect fitment, literally a one minute install and unlike some, i DEFINITELY heard a difference in spool up and turbo sound. and it's the only airflow mod i have, and the difference came immediately and only got somewhat louder after install, so i owe it all to my lil HKS friend.

 

[Baddmnkey]

Don't want to hijack the thread...but my question is on topic.

Does anyone have an opinion on the Cosworth Drop In Filter, do I need a custom tune for it? I'm currently running Cobb Stage 2 on an 09 WRX with 2,500 miles (yeah I could'nt wait to start adding power). Cobb's website clearly states OEM filter, but Flatirons Tunning told me I would'nt have any issues....and b4 you flame me, yes I've searched?

thanks

Ive been running the cosworth a/f for about 9k miles, perrin stage1, and no problems. Just switched to the AVO since I needed a new filter.

 

[2009_WRX]

I have an AVO filter as well. It has been working excellent so far. can't really say anything about other brands of drop-ins though. had the filter on for about 5,000 miles so far.

 

[rosscad]

Not sure if the following applies to the 08’s, I know for a fact it applies to the 09”s:

According to the manual only the Subaru paper drop in filters can be used, any other drop in filters / intakes will make the car run lean. Also COBB has warnings about this in the notes for the maps. You need a special tune for any other drop in filter / intakes.

I know people will argue with this and post that there car is running fine with no problems. Look at your manual and look at the map notes for COBB if you don’t believe me.

 

[monkiboy]

Not sure if the following applies to the 08’s, I know for a fact it applies to the 09”s:

According to the manual only the Subaru paper drop in filters can be used, any other drop in filters / intakes will make the car run lean. Also COBB has warnings about this in the notes for the maps. You need a special tune for any other drop in filter / intakes.

I know people will argue with this and post that there car is running fine with no problems. Look at your manual and look at the map notes for COBB if you don’t believe me.

who cares what people say. one can't expect their subaru manual to say "only genuine subaru paper drop in filters can be used. oh and the perrin drop in is safe too, but just these two."

have you looked at your logs, particularly afrs, pre and post drop in filter? definitely tune for an aftermarket intake, not needed for a drop in.

 

[2009_WRX]

^^^ well, even after running the AVO, was only running slightly leaner than stock. stage 1 changed that however...

I don't believe a tune is needed for just a drop-in, even an aftermarket one.

 

[imstuner]

I have a Blitz and 2 Avo drop in filter but I like the AVO one more.

 

[rosscad]

From COBB tuning website notes on the AccessPort:


MUST USE FACTORY INTAKE SYSTEM and FACTORY INTAKE FILTER. NO
OTHER AFTERMARKET INTAKES, OR DROP-IN REPLACEMENT AIR FILTERS ARE CERTIFIED
COMPATIBLE WITH THIS CALIBRATION. THE USE OF A DROP-IN REPLACEMENT AIR FILTER WILL
ALLOW THE VEHICLE TO RUN LEANER THAN DESIRED, WHICH CAN CAUSE ENGINE DAMAGE.

There is a special map for the AccessPort for the Perin drop in filter.

 

[rtmccormick]

From COBB tuning website notes on the AccessPort:


MUST USE FACTORY INTAKE SYSTEM and FACTORY INTAKE FILTER. NO
OTHER AFTERMARKET INTAKES, OR DROP-IN REPLACEMENT AIR FILTERS ARE CERTIFIED
COMPATIBLE WITH THIS CALIBRATION. THE USE OF A DROP-IN REPLACEMENT AIR FILTER WILL
ALLOW THE VEHICLE TO RUN LEANER THAN DESIRED, WHICH CAN CAUSE ENGINE DAMAGE.

There is a special map for the AccessPort for the Perin drop in filter.

cobb's maps are very conservative and their directions for running the maps are also very conservative, mainly because they have an image to protect. their stage 1 map is pretty much garbage anyway, they spent most of their development on the stage 2 map since it actually makes real power.

the addition of a panel filter isn't like a CAI; the MAF sensor remains in the stock location with stock diameter of piping around it. if the panel filter allows more air to pass through it into the engine, the sensor will sense it and adjust fueling accordingly. i ran an AVO panel both in my stage 1 and in my current stage 2 setup with no discernible changes in AFRs. as a matter of fact, when i put the filter on with my stage 2 map, it actually resolved a nagging knock issue that i had.

also, there is no special cobb map for the perrin filter.. other map makers(perrin, rallitek, etc) allow the use of a panel filter with their maps.