On a WS6 Ram Air. The K&N has a system that does away with the stock air box. It has a big filter that lays in place of the air box. How well does this work compared to the Slp cold air kit? Thanks for any replys.

 

Just the K&N filter alone won't add any hp. I am skeptical about the SLP cold air kit and other forms of ram air. It's hard to dyno the gains of something like that because theoretically the gains depend on how fast you are going. Most people that comment on these type of systems say the car felt faster after installing.

Personally I would go with a lid or K&N FIPK. I am not sure how much better the FIPK is then the lid, but the FIPK would have better gains. The 2nd and last item on this page are the two items I am refering to.

 

its tough to tell for sure, but the K+N FIPK is probably not quite as good only because the filter element is exposed, so it's directly taking in the hot air inside the engine bay. i went with the slp lid and did the free ram air mod in order to suck the air up from under the car where the intake charge will be cooler. it's jsut my opinion, but it seems logical to me.

 

I can prove that the SSRA works at speed. But you have to come to the track with me.
Ran 2 passes with it open. Then ran 2 with it closed, slowed down .1 and 1mph. Ran 2 more with it open again and got the .1 and 1mph back.
Lid with paper filter and SSRA.