[s-cars] More dyno results

[Dave Forgie]

Dave:  This is not another "vote".  I am just going to modify my
previous post.

I still think that there was a loss when you removed the exhaust.
However, as I thought about it more (while shaving - ouch!), I think it
has more to do with the fact that with an exhaust system, the individual
exhaust pulses (pressure waves) leave a "vacuum" (low pressure) in their
wake.  This low pressure helps to draw out/along the next pressure
wave/exhaust pulse, and so on. However, it you remove the confining tube
(the exhaust system) and dump the exhaust pulse directly into the
atmosphere, this low pressure assistance phenomenum is lost.  As a
result, you make less hp/less torque than with an exhaust system.
Having said that, I  think there is an optimum exhaust size for every
level of horsepower and, at some point, the stock exhaust is indeed too
restricting for these higher hp exhaust pulses (pressure waves) to get
down the pipe efficiently and the end result is less power than possible
with a somewhat larger diameter system.

Dave F.