Mmmmm i was expecting more power than that? I did find however when i put the Harvey headers on with his up-pipe it did make a differance that you could feel straight away. Considering they are only the oe ones ported {not the up-pipe} for the money i was very pleased. In the defence of Vince he is a very very good mechanic not a tuner. He took the advice of RCM = Olly but i agree going for 450ish horses headers should of been speced.