I have a UK 2002 WRX and want to upgrade the air filter this weekend. From what i've read on this forum an induction kit seems like a bad idea so i'm going to fit a replacement performance filter.

What do you guys recommend, K & N or Green performance filter?

 

The filters like k&n which rely on oil to do the filtering can mess with the maf.

IMHO stick with standard but maybe change it more often.

 

The Green ones are oiled, but are considered less damaging to the MAF. Well thats the reason I got mine, and its a huge improvement over the ITG one I had.

 

Will i loose out on any performance gains by sticking with the standard filter?

I've had the centre cat removed already and a larger bore exhaust from where the cat was to the back including back box. I plan on de-catting the downpipe and having a remap done soon. Are there any performance filters that aren't oiled?

 

I got the green one and it does make respose better

 

I use a Pipercross foam filter, high flow, no oil, washable. Works for me, very little hassle.

 

k&n say it doesn't

 

Green

 

i have Simota - no issues and FEELS like a gain

 

Thanks for the advice, i think i'll go for a green.

Will i get an increase in induction noise with one of these?

 

hi,

green for me, and yes it gives a little more induction noise. to be honest the induction noise is the only definate difference i noticed.

cheers and good luck.

 

PICPower : Don't be misled by some of the disinformation posted on here.

The O/E Subaru air filter is actually pretty good in terms of both filtration ability and power output.

To say that a K+N filter will screw up your MAF Sensor because of the oil on it is total rubbish, unless of course you are silly enough to grossly over oil the gause when servicing it. The advantage of the K+N is that it can be re-used so you can clean it as often as you want.

The performance difference between O/E and aftermarket panel in terms of filtration ability can be quite signifigant but in terms of power output is VERY marginal. Avoid a wide mesh filter which can let large particles pass which will bombard your MAF Sensor and worse still enter your engine internals.

 

Sti panel filter was recommended to me by a very confident and highly regarded mapper.