exhaust system idea

[Bruce Plecan]

-----Original Message-----
From: James Weiler <james at brc.ubc.ca>
To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
Cc: eec at eelink.net <eec at eelink.net>
Date: Saturday, March 13, 1999 8:52 PM
Subject: exhaust system idea

Called cutouts,  usually illegal.  
If ya get caught with them it goes on your permanent file..
Some cops judges really don't like em.
Bruce


>gang,
>
>I occured to me yesterday to ask a basic question about exhaust systems.
>Since it's an advantage to have staged throttle bodies (like in 4 barrel 
>carbs) why not do the same for an exhaust?  I imagine such a system could 
>have a HUGE pipe between the header and the muffler and then two pipes 
>exiting the muffler and going out the back.  However one would have a 
>butterfly valve in it and at low RPMs and low engine load it would be 
>closed. However at high RPM and/or high load it would open.  This second 
>tube could even bypass the muffler to reduce back presure.  OK, what am I 
>missing here?  Are the gains too small to be worth it?  This system could 
>be quiet most of the time and a screamer when you want/need it to be.
>
>cheers,
>james
>  
>