Posted by Karl on January 13, 2001 at 11:00:21:
In Reply to: The well discussed Exhaust manifold question posted by Gene S on January 12, 2001 at 20:20:46:
Here's the difference:
1. Bavaria had two separate three-port manifolds that each dump into their own exhaust pipes--so there are two exhaust pipes down to the front (dual inlet) muffler and no cat.
2. 528i (e12) has the front three exhaust ports join the rear three into a single exhaust pipe--so there is one pipe running down to the cat and dual outlet from the cat to a dual inlet muffler.
3. 533i/535i (e28) has two separate three-port manifolds. their outlets are joined by a Y-shaped exhaust pipe to a cat with single inlet/dual outlet, followed by dual inlet muffler.
4. 535i (e34) has two separate three-port manifolds. Then dual exhaust pipes with a crossover lead to two smaller cats, followed by a dual inlet muffler.
Any of these can be installed into our cars, but you need to either get manifilds and exhaust pipes as a set or be proficient with a welder. (I'm not a welder, so I got a set)
Any of these will be an improvement over the thermal reactor, in terms of reducing temperature under the hood and improving performance. But if you want the cat to work you'll need a closed loop fuel injection, with an O2 sensor and 528i computer. But that's another thread...
You may want to add this list to the FAQ
Karl