Posted by Randy on January 13, 2001 at 14:59:46:
In Reply to: Re: The well discussed Exhaust manifold question posted by Nate on January 13, 2001 at 10:52:50:
I have a '75 530i that I removed pollution equipment and thermal reactors. I replaced the thermal reactors with "mini headers" that allow stock exhaust pipes/muffler and heat shields. My opinions follow:
1)Save all parts. They may be of value to you or someone else later on.
2)Okay to remove all the electric vacuum valves, but I recommend leaving the black one connected. It will disconnect vacuum retard to the distributor under certain conditions (this is a good thing).
3) Okay to remove the small vacuum switch (no electric connection, 3 vac lines)that controlled the EGR.
4) Remove air pump and EGR (can fashion plug to intake manifold with large/short bolt and J-B weld).
5)The modules over the brake booster (those without vacuum lines) need to be kept. They include the double relay (fuel pump), speed switch (ignition, operates black valve noted above), and cold start relay.
BTW, I reused one of the small electric vacuum switches to disable vacuum retard to the distributor whenever the coolant temp switch in the radiator switches on the aux cooling fan. This speeds up engine/fan speed as well as reduces combustion temp when idling, allowing for a cooler running engine (at idle).
Randy