Well OK guys, actually I guess I'll have to 'fes up and admit that I
actually was just having a little fun and pulling Gene's leg.I guess I
asked for it and brought you all out of the woodwork!!
But anyway now that you all have responded, and seeing we all will have
to admit that noone has any real facts on this, and therefore it is
quite possible that the whole idea is mythology, I'll add my bit of myth
and opinion to it.
Presuming that one already had headers, two low back pressure mufflers
going into a three inch tail pipe, I would presume that changing to one
single muffler at the back would create more resistance to an equal
amount of exaust than two mufflers at the front. Further, the resistance
of a muffler at the rear where the exaust is at a lower temperature than
if it was up at the front might have less of a scavenging effect, and
therefore more resistance to the flow.Afterall don't the header coating
guys claim that by keeping more heat in headers, they get the exaust out
of the motor more efficiently creating a scavenging effect and creating
more horsepower. Perhaps the same would hold true for the muffler
situation.
Next, if you listen to the noise of a motor, it is heard at the end of
the tailpipe, not especially at the muffler. So why should it be any
quieter with muffler at the back? The mufflers are well behind the
driver seat area anyway, being somewhere under where the table is, so
noise level should be almost identical. The same holds true for
temperature in the motor area- why would it have any affect on
temperature in this area at all-except mayby if one is stopped with the
motor running and when heat from the muffler area may rise up into the
motor area. Any time when one is running down the road, the wind will
carry the heat toward the back of the vehicle.I can see, however, there
will be less heat penetrating the floor area in the front living area.
And I suppose its cheaper to replace one muffler than two- but even that
is presuming one will last longer than two would, so even that is
uncertain.
Now also if the muffler is at lower temp. at the back, and suppose one
runs the motor for short periods in the yard etc. it will get more water
and acid sitting in it than if it is further up the pipe line toward the
motor, so presumably it will deteriorate more quickly.
I have heard it said that the GMC does not in fact have enough
backpressure to necitate a change to a 3" exaust system.Short of actual
testing, who knows.I did it any way and also put on headers. Did it
give me any more power? I really don't know, I never noticed any
difference. But then maybe I didn't need to stomp on the gas as much to
get equal power. I like the headers,as since converting to them I have
had no further problem with leaks at the manifold in about 8 years.
So that's what I think--at least for today--who knows what it might be
tomorrow. Can you show my rationality to be wrong, confused or whatever?
I'm waiting and listening.
Claude.
PS.-Gene, I'm sure when you get all those extra measuring gauges you
will post them up on your site!!
Still having fun. CB.
actually was just having a little fun and pulling Gene's leg.I guess I
asked for it and brought you all out of the woodwork!!
But anyway now that you all have responded, and seeing we all will have
to admit that noone has any real facts on this, and therefore it is
quite possible that the whole idea is mythology, I'll add my bit of myth
and opinion to it.
Presuming that one already had headers, two low back pressure mufflers
going into a three inch tail pipe, I would presume that changing to one
single muffler at the back would create more resistance to an equal
amount of exaust than two mufflers at the front. Further, the resistance
of a muffler at the rear where the exaust is at a lower temperature than
if it was up at the front might have less of a scavenging effect, and
therefore more resistance to the flow.Afterall don't the header coating
guys claim that by keeping more heat in headers, they get the exaust out
of the motor more efficiently creating a scavenging effect and creating
more horsepower. Perhaps the same would hold true for the muffler
situation.
Next, if you listen to the noise of a motor, it is heard at the end of
the tailpipe, not especially at the muffler. So why should it be any
quieter with muffler at the back? The mufflers are well behind the
driver seat area anyway, being somewhere under where the table is, so
noise level should be almost identical. The same holds true for
temperature in the motor area- why would it have any affect on
temperature in this area at all-except mayby if one is stopped with the
motor running and when heat from the muffler area may rise up into the
motor area. Any time when one is running down the road, the wind will
carry the heat toward the back of the vehicle.I can see, however, there
will be less heat penetrating the floor area in the front living area.
And I suppose its cheaper to replace one muffler than two- but even that
is presuming one will last longer than two would, so even that is
uncertain.
Now also if the muffler is at lower temp. at the back, and suppose one
runs the motor for short periods in the yard etc. it will get more water
and acid sitting in it than if it is further up the pipe line toward the
motor, so presumably it will deteriorate more quickly.
I have heard it said that the GMC does not in fact have enough
backpressure to necitate a change to a 3" exaust system.Short of actual
testing, who knows.I did it any way and also put on headers. Did it
give me any more power? I really don't know, I never noticed any
difference. But then maybe I didn't need to stomp on the gas as much to
get equal power. I like the headers,as since converting to them I have
had no further problem with leaks at the manifold in about 8 years.
So that's what I think--at least for today--who knows what it might be
tomorrow. Can you show my rationality to be wrong, confused or whatever?
I'm waiting and listening.
Claude.
PS.-Gene, I'm sure when you get all those extra measuring gauges you
will post them up on your site!!
Still having fun. CB.
