K&N does have a FIPK kit for it I think, but it's kind of expensive. If you want more power there are headers, cams, ignition kits, even turbo kits. I got a cam off ebay from a guy called engnbldr and it's nice. I think it costs around $100. LC engineering specializes in 22re performance and have everything you could possibly want, but they are pricey. Google LC engineering.