nitrous is about the cheepest way to get there, till something malfunctions and melts a piston, most cheep n02 systems are for wet flow intake manifolds (like a carb or tbi set up) a correct system for a bimmers dry flow intake would have nozzles in each runner of the intake supplying fuel and n02 at the proper mixture, 70 hp wouldn't be too hard but would probably cost over $500, can't say how long the motor/driveline would last, it might not mind too much or it may cough up the head gasket on the first squease

Quote Originally Posted by wat_sup2002
Also, are there any cheep ways of gaining about 70hp?