the csl has an i-6.

You gotta be more specifin on the year man. The gtr has a v8 though.

the M3 gtr has a V8 proto type engine. both versions the street and the race version. BMW needed to develope the street version because the m3 didnt have the same engine as the race car and according to DTM rules, the car needs to be sold on at least 2 continents so bmw made 2 m3 gtr's. the difference in the engines: race-444hp street-380hp