Observation #1: Exhaust comparisons. They seem to follow the trend of removing the stock exhaust and replacing it with an aftermarket unit with an increase of diameter by .25". They compare the dyno results and say this exhaust is good or bad whatever the case may be. Flaw: The a/f ratio has just changed from a rich to a lean condition. I would suggest establishing a baseline of 12.5/1 ratio, test one exhaust, then swap to a .25" larger one and repeat. See the results. Go one more .25" large then test again.
Observation #2:
What the Contour needs is a fully resonant tuned exhaust. Working on one Terry?
Observation #3:
What is the stock overlap between the exhaust and intake valves? When you reduce back pressure, it is equivalent to increasing valve overlap, and when you increase back pressure, it is the same as decreasing the amount of valve overlap. So we should alsom be talking about cams.
