Variable Restrictiveness Exhaust

[Ord Millar]

I use high flow cats.  For the 1 or 2 HP difference, I really don't think
it's worth the risk of legal problems or injuring my environmental
consience. ;)

On the other hand, I am wondering if I could improve low rpm torque if I
could add a variable restrictor??

-----Original Message-----
From: William T Wilson <fluffy at snurgle.org>
To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
Date: Thursday, May 13, 1999 4:35 PM
Subject: Variable Restrictiveness Exhaust


>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.
>
>