On our Air Filter side of the business, we spent lot of time in Clean rooms
verifying noise using the DB meter and soon realized there were considerable
factors we had to explain.
Naturally we use data from a location that had the lowest DB.
---------- Forwarded message ---------
From: Todd Sullivan
Date: Tue, Jan 25, 2022 at 8:53 AM
Subject: [GMCnet] Re: Quiet Exhaust Question?
To:
Jim’s comment reminds me of a lesson learned while dune riding a dirt bike
with the fiberglass pole and flag required for visibility. If the
flag(which mounts via the rear axle) is installed on the muffler side the
hot gasses from the muffler quickly make short work of the fiberglass pole
despite the fact that the pole is several inches to more than a foot away
from the exhaust tip while underway.
Sully
Bellevue wa
> There is a reason why on a RV we prefer to exit to the side and down.
> When towing a car, it is preferable not to have the Hot air hitting
> directly onto them. Also less chance of bending the pipe tip. If you use a
> DB meter, the noise outside is the same if the pipe exits to the rear or
> side. Just sound different inside.
>
>
>
> > GM experimented with no mufflers, by denting the exhaust pipe as well as
> > the tailpipes. It was good when the cars were new, but the aftermarket
> > exhaust providers raised "HOLY NED" with them because they had to
provide
> > similar exhaust systems. What usually happened was that the OEM stuff
got
> > replaced from manifold flanges to end of tailpipe with conventional
> > systems. Customers were none to happy about the bills for that. GM
> changed
> > back in a couple of years. Then came "catastrophic convertes"
resonators,
> > etc.
> > Jim Hupy
> > Salem, Oregon
> >
> >
> > > I fixed the rap by running the exhaust straight out the back rather
> than
> > > pointed out the pass side. I barely hear it at all now
> > > ________________________________
> > > From: Terry via Gmclist
> > > Sent: Sunday, January 23, 2022 4:51 PM
> > > To: gmclist
> > > Cc: Terry
> > > Subject: [GMCnet] Re: Quiet Exhaust Question?
> > >
> > > Mine is quiet with 2 mufflers up front and a long pipe to the right
> rear
> > > corner. Pipe is 2.5 inch diameter. If I ever woke anybody up in a
> > campground
> > > they must have been sleeping in the road. Maybe the insides of one or
> > both
> > > of your mufflers has corroded away and is not cancelling the sound
> wave.
> > > Headers up front are definitely louder than cast iron manifolds and I
> > also
> > > have those courtesy of the P.O.. I also have the fender liners
> installed.
> > > Sitting in the driver's seat I can barely hear the engine running.
> Engine
> > > tuning can make a big difference in the amount of sound emitted from
> > > headers, but usually will be accompanied by loss of normal power
output
> > > and poor fuel economy. If it runs well and smooth I would
check/replace
> > the
> > > mufflers first,especially since I have the equipment to tackle that
> job.
> > A
> > > resonator is just another muffler and will quiet it more (and
eliminate
> > > exhaust "crack") but also may cost just as much to procure and get
> > > installed as replacing the mufflers. Depends on where and how you
shop.
> > > --
> > > Terry Kelpien
> > >
> > > ASE Master Technician
> > >
> > > 73 Glacier 260
> > >
> > > Smithfield, Va.
> > > _______________________________________________
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> >
>
>
> --
> Jim Kanomata ASE
> Applied/GMC, Newark,CA
> jimk
>
http://www.gmcrvparts.com
> 1-800-752-7502
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Jim Kanomata ASE
Applied/GMC, Newark,CA
jimk
http://www.gmcrvparts.com
1-800-752-7502
