[DeTomaso] Is anti-reversion the answer ?

[Mike Drew]

Chuck,

Those who attended the POCA Fun Rally last year got to see a comprehensive presentation by the POCA president, Gerry Romack, on the cause and fix for the dreaded exhaust system boom in the cabin. Turns out it’s caused by exhaust pulses bouncing off the washers that are welded to the ends of the resonator tips, inside the mufflers. He showed how he performed surgery on his mufflers, enlarging one washer on each side to change the frequency (or something) and that cured it. 

Contact Gerry and he will send a many-page PDF showing exactly what needs to be done.

I was able to reduce my boom by doing slightly different surgery on my mufflers, as well as heavy dynamat and soundproofing inside the cabin....

Mike

Mike

Sent from my iPad

> On Apr 11, 2019, at 13:19, Charles Engles <cengles at cox.net> wrote:
> 
> Dear Paul,
> 
>               I am not sure that anyone has completely correctly identified
> the source of the infamous drone.   Mike Drew, IIRC, reported driving one
> particular Pantera with some sort of special or custom headers that defeated
> the drone.  
> 
>                Anti-reversion header design has been around for a long time
> with its primary purpose to improve performance by minimizing reversion.  I
> don't recall any mention of reduction of exhaust noise.
> 
>                                 Warmest regards,  Chuck Engles
> 
> -----Original Message-----
> From: DeTomaso [mailto:detomaso-bounces at server.detomasolist.com] On Behalf
> Of Paul Rimov via DeTomaso
> Sent: Thursday, April 11, 2019 2:29 PM
> To: DeTomaso at server.detomasolist.com
> Subject: [DeTomaso] Is anti-reversion the answer ?
> 
> Caught a you tube video the other night and was quite intrigued with the
> header design. It had anti-reversion collectors on all the primary tubes.
> The theory is the design reduces backward pulses and increases exhaustion
> flow. Assuming this is the root cause of the 2000 drone would headers
> designed in this fashion aid in drone reduction and exhaust flow?
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