Insighter said:K&N filters can improve air flow, but they also let in more contaminants in the process. Not a good idea.
Alright, is there a K&N filter in the S2000? I'd rather go with what Honda engineers determined was best than what GM (you mentioned Corvette) engineers think is best. My brother (clutch hose to close to the Camaro engine caused engine fire), grandfather (Cadillac aluminum block cracked at 60,000 miles) and aunt (Grand Am would not start sometimes throughout the life of the car) have all had wonderful experiences with GM engineering.Okay first off, NO Honda wouldn't have included a K&N filter. Since they already are losing money on the car, it would make no sense for them to spend more. About $30 for the K&N, compared to $10 for paper.
It is my understanding that small contaminant particles DO matter. I was looking at putting a K&N filter in my 280zx. I go to a Z specialty shop that services all generations of Z's (and has for 20 years), and every mechanic there told me that K&N filters involve a tradeoff between engine contamination and performance.A 5 x 5 inch. section of a freshly oiled air filter is placed on the mounting plate and secured. The test machine is turned on and one teaspoon of Standardized Air Filter Testing Dust is sprinkled on the top of the filter section. The machine is then shut off and the filter section and pvc tube is removed in order to inspect the white oiled foam pad. In each test of a oil-wetted gauze filter test (K&N), the oiled foam is gritty and full of test dust particles as is the inside of the PVC tube. A paper air filter also lets the test dirt through but varies depending on the quality of the paper filter.
When the exact same test is replicated with a section of an AMSOIL Two-Stage Foam Air Filter there is absolutely no test dust particles on the oiled foam.
If the same test is run again, only this time lightly tapping the top of the filters, simulating vehicle impacts and vibrations, the test dust ingress is even worse for the oil-wetted gauze (K&N) while with the AMSOIL foam filter there is still no test dust particles on the foam.
This test comparison shows how oil-wetted gauze and paper air filters do not stop dirt particles as well as an AMSOIL Two-Stage foam filter does. Sure, they may flow air very well on a flowbench, dynomometer and in high performance applications, but what good is all the airflow if the filter isn't trapping and holding all the abrasive dirt particles?