and what can i do to reduce back pressure as possible ?? thanks
no the only time you will get any benefit from changing the exhaust is when you change the whole thing. the manifold is the most important part that's where the pressure issues start by fitting a 4 branch manifold you will allow better gas flow and reduce hot spots. unless you are thinking of doing allot of modifications i wouldn't change anything as a proper exhaust system an be very expensive if you gust want to make the noise than change the back box but that is all you will get no power improvement from doing so.
If anything it will increase back pressure. That's why race cars run straight pipes.
