There are different jets you can use for N20. People generally use 75-200 HP shot of N20 but it can go higher than that. If anyone was to use N20 on the 1er, like a DD, then a 75-150 shot would be what they would use. But like Tee-Dub said you can make more power by mixing about 4 gallons E85 with the highest octane fuel you can get at the gas station and getting a Meth kit.
There is also dry and wet shots of N20. Dry is sprayed in front of the intake manifold, usually in the intake piping or generally before the MAF and 75 is about the most you want to do with that since people say it's the most "dangerous". Wet is sprayed into the engine while mixing the N20 and fuel and its limited to how well your engine is built and is considered the safest.