Hi sir i was also wondering thé same question.... Would this exhaust affect thé engines ability in any way.... Thé akrapovic exhaust is thé Only one i know that doesnt but im not to keen on it... I have a friends Who has a SC project exhaust on his and he says it affects thé performance as theres too much air in thé blend If you know what i mean.... If anybody knows any more info about thé ixill x55 exhaust i would appréciate it so much.. thankyou