Old Library

<<Date: Fri, 11 Jun 1999 01:51:03 -0400
From: "V-Dubbin'" &lt;&#110;et.srfr&#64;sympatico.ca&gt;
Subject: [gti-vr6] cat. converter questions

when funning forced induction anyone get any gains on punching your cat or a
free flow?
is it worth it or just stick to stock?
how do oyu know when your cat is plugged up?>>

We saw only 3-4hp gain when using a test pipe on a NA VR6.  Therefore, the
cat is not a very large restriction on the VR6.
I would recommend replacing the cat with a test pipe before destroying a ~$1k
part for so little power.

Todd
Air & Water
www.awe-tuning.com

Todd, listers:
Some folks at Velocity Sport Tuning also tried removing the cat on a NA VR6,
and they experienced a major loss of torque due to insufficient back
pressure.  Has anyone experienced the same?
-Doug
'95 Jetta VR6

First of all, why do you want to remove the cat?  I've
shown numerous times via dyno testing that the cat
doesn't cost you any power at all.  If your cat is
bad, get a new one from TT for around $200.

All you'll be doing is making your car louder and
polluting the environment.

-josh

--- Scott U &lt;&#103;r8scott95&#64;hotmail<img src=/i/dc.gif border=0 width=35 height=15>&gt; wrote:

> I have been thinking about replacing my cat with a straight pipe but I am
> still unclear what I need to do with the O2 sensor.  Can I just have a
> fitting wielded in the pipe? Or do I need some kind of simulator (guy at
> muffler shop said that's what I needed) to keep the car running properly.
>
> TIA,
>
> Scott Ulrich
> 95 GTI VR6

Actually the TT folks in Oregon don't recommend removing the cat either.

BTW, did I mention how nice the TT 2.5" system sounds?

It sounds nice!
David

We've done many back to back tests and other than turbo cars you just don't
have anything to gain. On OBD2 cars it's not worth staring at the CEL anyway
;-) The OEM cat flow extremely well, if you can find one for a reasonable
price that's the best route.


Best regards,

Jeremy Williams
Matrix Engineering
4060 SW Macadam Ave.
Portland, OR 97201
503.443.1141 Tech
503.443.1142 Fax
888.249.0013 Orders
jeremy@matrixengineering.cc
www.matrixengineering.cc

Scott, 

Believe whatever you want, but I've done the dynos to
prove my views.  A straight pipe on a Vr6 (or G60 for
that matter) makes NO more power or torque than the
factory cat, assuming the cat is in good working
order.

Been there, done that.  Do the planet a favor and put
the cat back on.  If you want noisy, run a straight
pipe from the cat into a single flowmaster.

-josh