Performance Stages
Street Stage (SS): increased responsiveness from engine and suspension without major expense or compromise to ride quality
Street & Track Stage (STS): further increases in all aspects of performance, compromises in ride quality and comfort are acceptable at this stage. Still streetable---good driver school cars are at this stage.
Track and Race Stage (RS): all possible modifications are acceptable and desirable at this stage; still possibly streetable, but only by fanatics
Engine Power:
BMW engines are highly evolved and efficient as they come to us from the factory. It is virtually impossible to find substantial horsepower or torque improvements through minor manipulations of a healthy, well tuned BMW engine. Big changes can only come through big effort, big money, or both.
Minor improvements can be achieved through changes to the engine management software---either by replacing or reprogramming the “chip”.
Some engines benefit from installation of low restriction air filter housings, especially in combination with some device which assures that only cold air and not engine-heated air enters the engine.
See your specific car page for more specific recommendations.
NOTE: the simplest way to get a major increase in PERCEIVED torque is through a change in the differential ratio---again see the specific car pages for specifics.
Engine Conversions
---are not for everybody, but for the select few, the really discriminating owners, nothing less will do. For those not satisfied with the status quo, not satisfied with “normal”, bigger engines are the way to true happiness.
Exhaust Systems
Stock exhaust: not bad, probably perfectly fine for most performance applications.
Mufflers: performance exhaust systems are free flowing and not restrictive. Factory exhaust parts fit very well and last a pretty long time. They are hard to beat. Less restrictive systems are available, but are usually louder than stock.
Further Modifications
Are available and plentiful----engine changes, transmission changes, fuel injection, turbochargers, superchargers, etc
Go To the Conversions Section [click here]