Re: da extractors dispute
As said above,
extractors will help!
Most people fit extractors for noise, this normally generates a performance degrade.
Extractors need to be fitted as a package with a complete exhaust.
Extractors or headers are only a part of the whole exhaust system, and like any other other system it needs to be teamed with the rest to maximise the benefit.
But if you want noise, simply accept the ones you have if you like the sound...regardless of performance
ONLY a DECENT exhaust fitter will point you in a direction that best suits your application.....to be honest i have seen stock manifolds with altered follow ons generate more power