Variable Restrictiveness Exhaust

[Bruce Plecan]

----- Original Message -----
From: William T Wilson <fluffy at snurgle.org>
To: <diy_efi at efi332.eng.ohio-state.edu>
Sent: Thursday, May 13, 1999 2:40 PM
Subject: Variable Restrictiveness Exhaust

Usually illegal.
Used to call em cutouts.
Within the last couple years still available from JC Whitney
Grumpy

> Okay, this seems to be the best place to talk about random, goofy car mods
> that just might work. :}
>
> Suppose I have a car that I want to pass emissions, but I also want it to
> gogood.  Why couldn't I make some sort of cat-bypass system which would
> allow the exhaust to flow openly at high revs, but flow through the cat at
> more "normal" RPM?  Maybe a solenoid-activated valve attached to the tach,
> or perhaps just a flap on a spring like at the top of a big-diesel
> smokestack.
>