S4-1

Why are dp's so expensive compared to a cat-back exhaust?
How would this set up work out?
Awe catback with testpipes(no cats)??

bostoned

cats are exensive. They contain precious metals.

JMSIV

Catalytic converters use an expensive metal (like platinum) to convert the unspent hydrocarbons to inert compounds. To do this, the gasses have to come in contact with the catalyst. You can get by with using less catalyst if you slow the exhaust flow down and give everything time to be converted. If you want high flow (less back pressure), then you need to use a lot more catalyst, and that is expensive, much more so than stainless steel pipes.

maxZugkraft

Saw your sig - it says AMD.
Does that mean you have an AMD reflash?
If so, how do you like it?
Is it worth the $$$?
I am thinking of biting the bullet and going for either the AMD OR GIAC.
Thanks.

S4-1

I drive a B5 S4 and my set up is gutted dps, no cats, and vm3 exhaust. The power gain is unexplainable. I am going to be buying a b6 S4 in about a year and was wondering what would happen if I ran testpipes on the b6 also I want the b6 s4's V8 to sound insane. How would the b6 sound with no cats and the awe non-res catback?

JMSIV

Insane.

04 Savant

BTW - it will be pretty insane whether that system be AWE, ASP, Thermal or Labree, all of which are 2 1/2" (I believe)! Hell, why not go 3"?!?!

SullyS4

I cannot imagine it louder. It's seriously loud as it is, but if you can get more power out of it by gutting the cats then that'd be cool. Might want to add 2 (out of a possible 4) resonators though if it is too loud. AWE told me their resonators don't affect power any.

S4-1

or do I have to go with 4 or 2 resonators?