how to get more out of a 316i 1800

[Gradon]

Does any know you to get more power out of a 316i 1800 with out spending much... its a M40 motor its a 1800 limited like a 1600????

[sa6eto90]

ECU remap ,good air filter ,new exhaust sistem + exhaust collector from m42 engine ,short differential 3,45 + .This is for good start ot modifications