exhaust system idea

[Ferman C. Lao]

Isn't this the same as the Shotgun or Shogun , forget what it's called
exactly that's marketed by Nology?  Looks like a butterfly valve on the end
of an exhaust pipe.
-----Original Message-----
From: xwiredtva at msn.com <xwiredtva at email.msn.com>
To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
Date: Monday, March 15, 1999 11:35 AM
Subject: Re: exhaust system idea


>DG Performance makes this type of muffler for 2 stroke Motocross bikes. If
>you call and ask for a brochure or visit your local motorcycle shop they
may
>have the cutaway. Uses a spring and a metal valve mounted into the middle
of
>the muffler. As rpm's increase it pushes the metal disc back opening up the
>muffler to a wider chamber were the exhaust can easily go around. I'm sure
>it can be done for your applications and improved somewhat. I ran it when I
>raced and it gave better low end but the top end was still the same.
>
>
>
>>Wasn't the original question about the concept of a variable back pressure
>>exhaust system?  I think the idea is great, low to mid rpm gets more
>>backpressure, then as rpm's increase, backpressure decreases to none.
>>That's where the open pipe idea came from.
>>
>>If this idea were coupled with a variable valve timing setup, it would
>allow
>>the best performance through all rpm ranges.  Of course, it's all shooting
>>from the hip theories!
>>
>>Jim Yeagley
>>1996 Dodge Indy Ram
>>See it and many others at: www.indyram.org
>>1975 Pontiac Grandville Brougham Conv. (in baskets)
>>webmaster at indyram.org
>>jimyeagley at stratos.net
>>
>>
>>
>>
>
>
>