[DeTomaso] ANSA mufflers

Pantdino pantdino at aol.com
Mon May 23 01:10:46 EDT 2011


Mike, is that with the meter on the A scale or the C scale?
The C scale includes much more low-frequency energy than the A, the latter approximating the human ear.

I believe the 90dbA  (A meaning A scale) OSHA limit is assuming the employee is wearing over the ear hearing protection. 

115db without protection would exceed the pain threshold for most people and cause permanent hearing loss in a very short time indeed.

If you are really getting around 100db on the A scale you NEED to wear ear plugs when you drive the car.

Jim






-----Original Message-----
From: Pantera Place <PanteraPlace at hotmail.com>
To: 'Pantdino' <pantdino at aol.com>; detomaso at realbig.com
Sent: Sun, May 22, 2011 1:31 pm
Subject: Re: [DeTomaso] ANSA mufflers


Jim,
 
Picked up a RS db meter today and did some testing.  At idle (performance
am at about 850 RPM) the interior db is between 104 and 106 with the
indows down.  Windows up deduces the db to about 98.  At WOT (up to about
,500) the interior db drops to about 98 and around 102 db cruising at 2,000
PM.  Much less when out of the 2,000 RPM range.  
 
Five feet behind the car at idle is 101 db.   I'm somewhat surprised at the
igh db readings, but because I've made the modifications one step at a time
he increase has been a slow process.  Expect I'm about a loud as I should
e without ear protection!       
 
OSHA work rules allow up to 90 db for 8 hours.  If the noise level reaches
15 dB hearing protection is required if the anticipated exposure exceeds 15
inutes.  
 
I'll do some testing with other Pantreras and see how the levels compare.  
 
Mike
 
 
From: Pantdino [mailto:pantdino at aol.com] 
ent: Saturday, May 21, 2011 8:39 PM
o: panteraplace at hotmail.com; detomaso at realbig.com
ubject: Re: [DeTomaso] ANSA mufflers
 
Mike,  
 
the resistance of airflow thru a tube is inversely proportional to the
ourth power of the radius-- so if you double the diameter of a hole the
esistance decreases to 1/16th. So yes, the resistance thru all those little
oles is much greater than thru a single  large hole.
 
What you describe regarding being disappointed with new mufflers being too
uiet is why I have not replaced the rusted-out, ratty-looking Ansas on my
ar.  I like the sound and that is more important to me than appearance.
 
Do you have a sound level meter?  You can get one at Radio Shack very
nexpensively.  It would be interesting to see what levels you get behind
our car compared to a GTS, Hall, and other systems.
 
Jim Oddie

 
 
-----Original Message-----
rom: Pantera Place <panteraplace at hotmail.com>
o: detomaso at realbig.com
ent: Sat, May 21, 2011 2:57 pm
ubject: [DeTomaso] ANSA mufflers
I've been working on a series of modifications to my ANSA mufflers to
mprove the exhaust flow and relieve back pressure.   The latest work is at
he bottom of this page http://www.panteraplace.com/page200.htm 



ike 



______________________________________________

etomaso Forum Managed by POCA

rchive Search Engine Now Available at http://www.realbig.com/detomaso/

eTomaso mailing list
eTomaso at list.realbig.com
ttp://list.realbig.com/mailman/listinfo/detomaso
______________________________________________
Detomaso Forum Managed by POCA
Archive Search Engine Now Available at http://www.realbig.com/detomaso/
DeTomaso mailing list
eTomaso at list.realbig.com
ttp://list.realbig.com/mailman/listinfo/detomaso




More information about the DeTomaso mailing list