I think the essence of a csl is not the power of the engine, but its balance and grip, so if your heart is set on modifying a csl- then I think best plan would be to remove as much weight, as well as a few choice mods....
but seeing as your track car is the crazy escort, you could get a stroker kit for your/another e90 ~530bhp is doable I think? That is a car I would like to see on track
