More IVA prep! Noise and self centering

[Talonmotorsport]

On a slight tangent here but bare with me...
When it comes to exhausts every body says 'oh you need it to be 100% free flowing' to get the best power, and for racing you need the engine to hit max rpm in every gear. On the road in the real world it's all about low down torque and drivability and this is where you need a little back pressure in the exhaust to give the pistons some thing to push against which gives you torque. The reason the car idles better is that the engine is not trying to run away with it's self, as it now has some thing to push against ie the little bit of back pressure your making it work for a living and controls the rpm better.