By fitting Mitsubishi TJ Sports muffler to my TJ Advance will I score a few extra Kw.
Alternatively Lukey equivalent. I realise the Sports muffler will be noisier. This looks like and attractive option to fitting a standard muffler. Mitsubishi probably uses Lukey as OEM.

dunno about the sports muffler.. but i put a 2.5" mandril cat back system (redback) with 2 sports mufflers.. the complete off the shelf system.. gaskets/bolts etc etc bolted straight on.. noticed more mid range and a bit better off the line.. just a bit better all round i think.. nothing to write home about.. but definitly better.. not loud at all... highly recomend.. you can buy the mid section and the rear (over the theoratical diff) section separate.. and ofcourse the extractor/high flow cat front half.. each part is designed to bolt onto the factory other part.. and they arn't expensive..

Definitely the best mod you can do to a magna's performance is replace the rear muffler. Very restrictive and you gain 8kw at the engine (in a perfect world lol).

just search the forums for the Lukey LR2779, its a common mod ;)