From studying the design of the Mugen twin loop I don't think it is a power upgrade and possibly even a power robber. many mugen parts are great additions and the exhaust is of great quality but the piping diatmeter is extremely small inside the canister. I recall around a 2" ID.

The Hytech twin loop designed after the Mugen would be a much better choice.

I run stock and can't decide cause everything makes the car louder.