Fwd: IML: Richer/leaner, was Exhaust system discussion

[FltSgt@xxxxxxx]

Larry

Remembering that any gas engine is nothing more than a power producing air 
pump;  the size of the exhaust manifold to header pipe gasket is 2 1/4 ".  At 
this point it states the engerineering dept realized this size ment something 
in the horse power and/or torque values.  In order to maintain this value 
they designed the routing ( clearance ) of the exhaust system to accept this 
size of tubing.

They also knew that dual exhaust is much better than single when one is 
trying to get better values.  But, ... the bean counters say that it you use 
single exhaust and charge extra for the dual we'll make a few bucks.  The 
bean counters also say what if we use a smaller diam pipe and at about three 
inches from the end we flare it out to the gasket size of the exhaust 
manifold.  The tech guys grind out the numbers and one day many years later 
some member of this group sez,  "...They made it that way for a reason and 
I'm sticking to the factory spec's of my 19__ __ Im per i ial...".  

As time goes on many producer's get into the muffler making business, and 
they give their product a catchie name.  We all know that marketing flash can 
sell a piece of junk.  Who makes a direct copy of MoPar's best flowing and 
factory quite muffler.  Walker does.  They have the Walker part number of: 
17749.  Walker also makes the same muffler with out the Walker label for 
NAPA..  Guess what number NAPA has the muffler listed under ?  If you came up 
with NAPA number 17749 you are correct.

I don't know what the maker info of the resonator is.  I do know the "can" is 
4" X 18" with 2 1/4 inlet/outlets.

Now that you know what the flow diam is, and how to quiet it down, add 
something that was not around when your car was being designed.  The "X" 
factor.  

My wife just asked if she could use the phone today so this is it (for now).

                                                 Rodger & Gabby

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• From: mullic5@xxxxxxx
• Date: Tue, 31 Dec 2002 20:55:22 EST

HI all; One thing I have not seen mentioned in this discussion is balance. I 
refer to the intake side of the engine. The original air cleaner on my 
Imperial had one very small opening about the size of a quarter. It has a 
single 2 in. exhaust. It seams very restrictive to me. When changes are made 
to one part of a system, you should consider the effects on other areas. I 
use an open element air cleaner on my car and should have improved the 
exhaust system at the same time. Time, weather, and $ prevented doing 
everything at once, so I will be putting dual 2.25 pipes and the new 50 
series flowmaster mufflers on when I can. I will use a crossover pipe (maybe 
an x system) if I can fit it in. 
    Just my $.02
    Larry 
    67Crown 4DRHT

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