Never waste your time with any "chips" or "turbine kits"
If anything they will cause damage to your engine
From my basic knowledge about them the chips tell your car that the air coming in to the engine is colder and mixes the fuel accordingly which will make it run rich all the time
the turbine kits "electric powered turbo's" don't suck enough air in to be beneficial in any way.. I think top gear did a bit on them and they used more fuel and got no gains
For the 2.5 there isn't really many ways to go performance wise - bang for your buck would probably be a lightweight flywheel or bolt on supercharger - or an upgrade to Z4M
