E34
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, turbochargers, superchargers, etc