Resonated Non-resonated?

[vidman2]

Excuse my ignorance but can anyone explain what the difference is between a Resonated and a Non-Resonated exhaust system.

Interested in loudness, drone, performance etc.

[GeoBog]

The difference is the non-resonated exhaust doesn't have the rear silencer box (some call it muffler), it has straight through pipe. This obviously means more sound but also more drone. I also believe they are illegal and on some cars they can fail the NOx testing during MOT.

[GrahamFR]

Q. What is a resonator and what's the difference between a resonated and non-resonated exhaust system?

A. A resonator is a chamber in the exhaust system that contains a specific volume of air which is designed to cancel out certain frequencies of sound (made by the engine) - making the exhaust noise quieter.

Therefore, a non-resonated exhaust system will give you extra performance and a louder exhaust note and the resonated system will give you extra performance without increasing the exhaust noise much.

From Milltek themselves.

Res and non res is not related to emissions or nox levels either sorry geo, just sound, you're thinking of a straight through decat pipe

[vidman2]

Thanks Guys