E12
Performance Stages
Street Stage (SS): increased responsiveness from engine and suspension without major expense or compromise to ride qualityStreet & 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:
Little
can be done to improve the induction system of a well tuned E12---the fuel
injection system can be tuned for maximum efficiency, but that’s about it.
For highly modified cars:
Triple Weber DCOE carb set-ups are also very popular, and rightly so. Though substantially more expensive, 40mm or 45mm DCOE side draft Webers give the utmost in responsiveness and the ultimate in performance improvement.
Ignition System Modification
1975-1978 530i
Consistency and reliability IS performance. One of the characteristics of ignition systems having ignition points is that the points WILL wear and they WILL get out of adjustment and the engine WILL get harder to start as this condition worsens.
Typically, the ignition points really need to be adjusted by around 6000-7000 miles, or about half way between Major Tunes. By getting rid of the points and replacing them with electronic equivalents, all traces of performance degradation are removed between services and the engine maintains perfect adjustment throughout the year.
Pertronix pointless conversion---removes the stock
ignition points and replaces them with a simple and reliable magnetic triggering
device.
Price:
parts about $75, labor $108-144
Crane/Allison pointless conversion---similar replacement
with an optical triggering device
Price:
parts about $120, labor $108-144
Hi-Energy Ignition
Just
getting rid of the points makes the system reliable, but it does not make
it a modern hi-energy ignition system. Hi energy systems fire the spark plugs
more reliably and under conditions that would cause misfire of a normal ignition
system. For example, hi compression and hi rpm require greater spark energy
to fire every single time---the only way to optimize performance.
MSD: Multiple Spark Discharge Ignition
This
is the state of the art. This system is found on virtually every race car
of almost every type throughout the world, and it works just as well for your
street car.
Price:
parts about $150, labor $144-216 (and up, many options are available)
Exhaust
Systems
Stock exhaust: not bad, probably perfectly
fine for most performance applications
Headers: even less restrictive, tuned headers increase extraction of exhaust gasses, especially at hi engine rpms. All race cars have headers; street cars driven in an aggressive fashion will also benefit. We strongly recommend Stahl Headers for their outstanding engineering and construction quality.
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 largely a matter of personal choice. They 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]