| Street Stage (SS): | Street & Track Stage (STS): | Track and Race Stage (RS): |
|
Increased
responsiveness from engine and suspension without major expense or compromise to ride quality |
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. |
All
possible modifications are acceptable and desirable at this stage; still possibly streetable, but only by fanatics |
Engine Power:
1977-1979 320i: these are 2-liter cars with CIS or K-Jetronic Fuel Injection
1980-1983 320i: these are 1.8-liter engined cars with a more refined
K-Jet Injection for use
with unleaded fuel and a catalytic convertor
The CIS-system somewhat limits performance
changes to the engine. Headers and exhaust
system upgrades make minor improvements. Camshaft changes are limited to 292
degree
duration, which is a bit better than stock. Early cars still had points, so
the ignition system
upgrades listed below will keep the engine running at maximum. Late cars really
benefit
from a 2-liter shortblock conversion, especially when combined with higher compression.
Dual Weber DCOE carb set-ups are also very popular, and rightly so. DCOE side
draft
Webers, in either 40mm or 45mm, give the utmost in responsiveness and the ultimate
in
performance improvement.
Please ask Terry for more info
about the 2-liter short block upgrade for
80-83 320s, and 5-sp conversions for early
4-sp equipped cars.
Ignition System Modification for 1977-1979 320i
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 stock 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 $88-145
Crane/Allison pointless conversion---similar
replacement with an optical triggering device
Price: parts about $120, labor $88-145
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
Tii exhaust manifold: slightly better,
slightly less
restrictive
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---engine changes, transmission changes for
77-78 320s, etc
Go To the Conversions Section