Who has used this header and what kind of results have you noticed. im working on a 250 WHP NA build and the exhaust is killing me, i just dont know what to go with. If you have used this header, did you have your car tuned afterwards, or was it just a bolt on? if you dont know what im talking about, heres a link: http://www.kteller.com/store/index.php/cPath/68_21_234 Im also interested to see if anyone has any results with the RMF and Endyn headers as well. There is not a whole lot of solid information on them with regards to the H22.