Posted by Troy Rudolph on March 28, 1999 at 11:59:51:
In Reply to: Just purchased '78 530i posted by Alex on March 28, 1999 at 02:19:03:
1) Make sure the radiator and fan clutch are in good shape. To test the fan clutch, reach in and give it a HARD spin with your hand. If it turns a full turn or more, replace it. IMHO, the thermostats fail frequently so just replace it.
2) If the car still has the thermal reactors on it, lose them and install Bavaria manifolds or headers (Paeco, Stahl) and nice high-flow exhaust to go with them.
After doing this, recalibrate the air flow meter to lean the fuel mixture. The 530i runs a rich mixture to support continue combustion in the thermal reactor. Without them, you can run a normal mixture and still have good power and burn less fuel.
3) Replace the old-fashioned "points" ignition with a modern high-voltage electronic system. You can get a '79 - '81 528i distributor, "spark box" and coil from a wrecking yard or use one of the aftermarket conversions. Use some high-quality spark plug wires to go with it. I've had good experience with Bosch Platinums; others here will disagree.
4) For highway use, a five-speed conversion is wonderful. It transforms the car. It drops the engine revs by almost 20% in fifth. (3000rpm = 62mph in fourth; ~2400rpm = 62mph in fifth.) The gas mileage is much better too.
5) Front strut tower brace to improve the rigidity of the front-end. You'll notice it right away.
6) Relocate the battery to the trunk to get some weight off the front.
7) Consider a larger front sway bar. I've been told (but haven't verified) that the one from a 3.0CS (25mm) will fit.
That ought to keep you busy for a while. And, it'll be fun too.