Totally agree with p0l0_Gti a remap will give alot more than 2 or 3 bhp!
Dont get me wrong N/A Engines wont get alot of power gains from a re-map but 8-10 BHP power gains have been proven.
Have you ever seen the results for a Mini One re-map - 90Bhp standard straight to 125BHP with the Map thats a 35BHP gain on a N/A engine and this has been proved by P-Torque. This runs the same engine as the cooper but has alot less power from standard. Cooper has 115bhp as standard and when re-mapped achieves 125bhp so +10 gain. Whereas the Mini one will shoot straight up to 125 because the factory settings are de-tuned.
There are Polo GTI's on here running 140-142 BHP that have been re-mapped so there's no point trying to say you will only get 3BHP when its been proven you can get more than that,
Exhaust, Induction Kit & Manifold will give very little gains maybe 5 to 6bhp maximum but a custom map from a respectable tuning company will give you 10bhp gain, perhaps 11 or 12 if your lucky. Doesnt do your gearbox any favours though
Ben,