mufflers

[darren paget]

When I went to the 3" exhaust I changed over to Flowmaster mufflers.
Keeps the restriction, nonexistent. A little throaty at the tailpipe but
no discernible noise inside. Stainless steel with a lifetime warranty.
About 1/3 the size of the OEM setup too. Darren

--
Darren Paget
76 Experimental
Another Fab Day
http://www.TZEplus.com

 

[john wright]

Justin,
I also have a 403 and run flowmasters mufflers. A little more throaty
at idle but not much louder than stocks going down the road. With less
back pressure on the exhaust system you will find that your gas mileage
will increase slightly and the motor will be a little more peppy. That
was my observation when I put them on last year.

>
> I need to replace my mufflers. Prefer to go with a quite muffler such as
> Walker to keep the co pilot happy. However if not available will consider
> others. Will appreciate brand, source, and part numbers. The ones listed in
> GMCI (Walker 21793) are no longer available. Would also like to check out the
> Flowmaster. How about the Flowmaster. Is it relatively quiet? Will consider
> any brand you care to recommend.
> Thanks
> Justin
> I have a 403. Don't know if this makes any difference.
>
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--
J.R. Wright
GMC GreatLakers
77 Eleganza II
Michigan

 

[paul bartz1]

Justin:

I , too, have a 403 with Flowmaster (#52553) mufflers and like them.

Paul Bartz

From: John R. Wright [mailtoowerjon]
Sent: Tuesday, August 08, 2000 7:11 PM

Justin,
I also have a 403 and run flowmasters mufflers. A little more throaty
at idle but not much louder than stocks going down the road. With less
back pressure on the exhaust system you will find that your gas mileage
will increase slightly and the motor will be a little more peppy. That
was my observation when I put them on last year.

>
> I need to replace my mufflers. Prefer to go with a quite muffler such as
> Walker to keep the co pilot happy. However if not available will consider
> others. Will appreciate brand, source, and part numbers. The ones listed in
> GMCI (Walker 21793) are no longer available. Would also like to check out the
> Flowmaster. How about the Flowmaster. Is it relatively quiet? Will consider
> any brand you care to recommend.
> Thanks
> Justin
> I have a 403. Don't know if this makes any difference.

 

[richard guthart]

Justin,

Just yesterday I had Flowmaster #52558's and 3" exhaust installed on my 455
so the sound of old and new are fresh in my mind. The new ones are
definitely louder (deep sound) when you plant your foot in it but only a
little louder when cruising at steady hwy. speeds. (I already had Thorley
hedders, installed by prev. owner.)

Incidentally, the conversion made my engine run leaner. Here are emission
test results before and after:

before after
CO% - idle 2.0% 1.1%
CO% - 2500RPM 3.1% 2.0%

I am going to turn the idle adj. screws 1/8 turn richer.

Richard ('77 Birchaven)
rlguthart

>

> >
> > I need to replace my mufflers. Prefer to go with a quite muffler such as
> > Walker to keep the co pilot happy. However if not available
> will consider
> > others. Will appreciate brand, source, and part numbers. The
> ones listed in
> > GMCI (Walker 21793) are no longer available. Would also like to
> check out the
> > Flowmaster. How about the Flowmaster. Is it relatively quiet?
> Will consider
> > any brand you care to recommend.
> > Thanks
> > Justin
> > I have a 403. Don't know if this makes any difference.
>
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: gmcmotorhome-unsubscribe
> For additional commands, e-mail: gmcmotorhome-help
>

 

[darren paget]

It leans out because the exhaust evacuates quicker and air intake cannot
keep up. It moves the products through the engine too fast. I fixed this
by using 2, 4" air intakes and a more efficient carb. Worked for me.
Darren

--
Darren Paget
76 Experimental
Another Fab Day
http://www.TZEplus.com

 

[darren paget]

The way I understand it is that without the back pressure of the exhaust
system, the engine burns fuel differently. I am not a mechanic and try
to understand what I am told and I do understand this, I am just no good
at explaining it. Darren

--
Darren Paget
76 Experimental
Another Fab Day
http://www.TZEplus.com