ST200 airbox vs stock box

[dhminer]

So what is a good brand had the k n took it out put stock back in don't see much difference

You won’t notice a difference in any intake you put on this car unless you upgrade the turbo too. It will add noise but no power. I refuse to use oiled filters out of laziness, so I stick with AEM dryflow for all of my cars and have for many years

 

[BadShot]

You won’t notice a difference in any intake you put on this car unless you upgrade the turbo too. It will add noise but no power. I refuse to use oiled filters out of laziness, so I stick with AEM dryflow for all of my cars and have for many years

Which AEM filter fits our cars? I don't see the FiST listed on their site. I also dislike oiled filters so that's an interesting option.

 

[dhminer]

Which AEM filter fits our cars? I don't see the FiST listed on their site. I also dislike oiled filters so that's an interesting option.

I’m not sure they have one for the stock air box. I’m using a 9” long cone filter

 

[XR650R]

If you go "stage 2," intake parts can give you some decent gains. https://dizzytuning.com/blogs/technical-documents/fiesta-st-stock-turbocharger-intake-testing

 

[M-Sport fan]

Which AEM filter fits our cars? I don't see the FiST listed on their site. I also dislike oiled filters so that's an interesting option.

I use an aFe Dry Flow filter# 31-10307 for a drop-in to the factory filter box, NOT oiled, but washable, panel filter.

I bought this maybe 3-4 years ago, so not sure if it is the same number, or even if it is still available from aFe or not.

 

[Dialcaliper]

I use an aFe Dry Flow filter# 31-10307 for a drop-in to the factory filter box, NOT oiled, but washable, panel filter.

I bought this maybe 3-4 years ago, so not sure if it is the same number, or even if it is still available from aFe or not.

I’m using the same aFe Dr flow that I bought a year and a half ago. Still available under the same part number.

No oil, just dry element that’s washable. It may not be quite as high flowing as the oiled filters, but it claims better filtration - basically the best you can get short in a washable reusable filter at 99.2% which is why I went that route. It’s comparable to some middle of the road paper filters

Your cheap parts store FRAM paper filter is between 95-97% efficient. The fancy “Ultra” or Heavy duty aftermarket paper filters can hit 99%. Top of the line High Efficiency (Wix) and OEM paper filters are usually 99.5%-99.9%, sometimes better. Donaldson makes what are basically HEPA filters used for big diesel engines that achieve 99.98%. They licensed the tech to Amsoil for their “nanofiber” dry filters. Unfortunately Amsoil only makes them for limited applications and are mostly discontinued or I’d be all over that. Specifically Cone filters branded for Injen, 14” cylindrical filters for carbureted engines, and a few random panel filters

By comparison your typical K&N oiled filter measures out at 95-98%. AEM Dryflow claims 99%, similar to the aFe.

Long story short.