[DeTomaso] Famous Pantera 2000 RPM exhaust resonance

[Mike Thomas]

I've got a full Mindtrain exhaust, and it does have the res between
1800-2000 RPMS, but not at idle.  I've often wondered if you can hear it
from outside the car, or only while seated.

Mike Thomas 

-----Original Message-----
From: detomaso-bounces at realbig.com [mailto:detomaso-bounces at realbig.com] On
Behalf Of Pantera Place
Sent: Monday, September 19, 2011 3:49 PM
To: detomaso at realbig.com
Subject: [DeTomaso] Famous Pantera 2000 RPM exhaust resonance

Kind of slow on the forum today, so I thought I’d toss this out for
discussion. 

 

One of things that has always puzzled me about various different Panteras is
the lack or presence of the famous Pantera 1800 - 2000 RPM exhaust resonance
or in the case of cars like mine with semi-aggressive cams the resonance at
idle at around 900 RPMs.   There doesn’t seem to be any single key element
that I’ve found in any of the Panteras causing the resonance and in my case
it permeates the complete back 2/3rds of body.  The body panel sections
between the doors and the tail lights vibrate at idle not counting the fact
that my garage windows severely vibrate.   

 

I actually enjoy the sound and setting off car alarms as I idle by is much
fun, but I still wonder was causes the phenomenon.   I recently drove a
Pantera that had the same Hall headers I have but Hall mufflers and there
wasn’t even the slightest hint of resonance.  The 72 engine also has a stock
cam and the DBa level at the back of the car is 91, twice as loud as my
modified ANSAs.   I have a friend with GTS headers, GTS mufflers that are ½
the DB level of mine, stock 71 engine and it has the resonance.  

 

I’m not trying to get rid of the sound but I recently added sound dreading
material to the inside of the firewall and as expected it had no impact on
the resonance.  The sound dreading did however reduce engine mechanical
noises, valve lash, etc. 

 

I’m interested in what experience other owners have with the resonance and
what combination of exhaust and engine medications they have.  Does
undercoating on the wheel houses impact the sound, etc. 

 

Mike

 

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