stock looking performance exhaust.

[evilC]

Originally Posted by redhot

So; how does the original Porsche systems work? It does not look like they are using the 4 into 1 systems most VW performance exhaust use, or do they have a collector inside the muffler? (both 914 and 911?)

The porsche is a 6 cylinder engine so 4 - 1 cannot work As with most 6 cylinder engines the scavenging effect tends to work with the coupling of each set of adjacent cylinder so you should get 6 - 2 - 1 as shown in the photo. The same arrangement on 6 cylinders work whether its a straight 6 V6 or flat 6. On a 4 cylinder to get scavenging the cylinders are coupled 360* out so that on an inline 4 with a firing order of 1,3,4,2; 1 is coupled to 4 and 3 couple to 2. The same applies to V8s so that is why the exhaust plumbing ends up looking like spaghetti.
then you start to consider single plane crankshafts..............................

Clive