Basically the viper give more power because it is a sealed unit, preventing much hot air getting inot it, unfortunatly on small engines this does not make any noise. If you want noise you will need to get an open induction kit, unfortuanly thos will get rid of any power gains wiht teh Viper, if you put plently of cold air feed to the open IK then you shouldnt loose any power. What i was told is that the power gains to be had wiht a viper are too small to be noticed on something like a 1.2, so you are better off getting a K&N and putting about 4 cold air feeds to it