View Full Version : Confused about Testpipe/Downpipe

08-18-2007, 11:13 PM
If I get a testpipe, i still need a downpipe, is this correct? Is there anything I can get that will do the whole deal? My friend did a 3" testpipe on his GTI last week and had to use a racepipe in addition. I'm just really confused on the whole thing... I searched, but I didn't really find what I was looking for.

08-18-2007, 11:26 PM
a testpipe replaces the stock Catalytic Converter
a downpipe replaces the stock downpipe.

im pretty sure theon our cars it basically looks like this(as a side profile):
if this diagram is wrong, someone please correct it so that im not providing him with the wrong information.

Turbo vvv




NPIPE--e-x-h-a-u-s-t--|CENTER MUFFLER|------|REAR MUFFLER|= <---exhaust tips
bold part is the flex pipe^^^

*yes, the K03 really is that small.[;)]

08-18-2007, 11:28 PM

08-18-2007, 11:29 PM
wow nice sketch!

Kyle H
08-18-2007, 11:40 PM
I always thought that our cat was the downpipe?

Nice picture, btw.

08-19-2007, 01:14 AM
source by mike

the down pipe is the piece that goes DOWN

arizona steve
08-19-2007, 01:15 AM
if you guys got under your cars every once in a while you'd have this all figured out!

most testpipes/high flow cats can be fitted to the stock downpipe (there is a cat AND a downpipe, there isnt one that is the same.)

4ringjelly got it right.

08-19-2007, 08:37 AM
alright, that's what i thought, but i just wanted to clarify. I knew what the testpipe did, just not the downpipe. Anyway, thanks guys. I think once I find out if my car is totaled or not i'll order both.

08-19-2007, 08:53 AM
I have a new setup going in soon. Fast Intensions 3"-2.5" 300 Cell HFC and Techtonis 2.5" DP. Bolting that together makes a hell of a downpipe. Pics coming soon.

08-19-2007, 09:18 AM
Hahaha. Nice diagram! Its soo simple!

08-19-2007, 09:27 AM
You will not pass emissions inspection in Virginia without a cat.

08-19-2007, 09:11 PM
virginia doesn't do smog/emissions at inspections(that i'm aware of), they just make sure there is no exhaust leak. I used to have a jeep wrangler that ran a straight pipe with a glasspack and that exhaust never had any issue passing inspections.