ryans4

"Back pressure in an exhaust system is evil"

"Turbos do not like backpressure; the lower the better"

These are all quotes from Corky Bell from his book Maximum Boost (Designing, Testing, and Installing Turbo Charger Systems).

So no, i didn't make them up on my own.

Since it seems that tha RS4 downpipe crowd is arguing up their stuff over basically all other downpipes (since all aftermarket downpipes remove the pre-cats, yet the RS4 downpipes retain them), i thought it was fitting to continue the argument.

I agree that flowbench numbers for exhaust components would be a great way to compare the options, but since no tuners do flowbench testing, that pretty much ends that discussion.

So what do we have to compare? Well, pipe diameter and catalytic converters. I don't care WHO made the downpipes for the RS4, if they have 4 cats, and the aftermarket ones have 2 cats, i'm buying the downpipes with 2 cats.

Last time I checked, putting ANYTHING in an exhaust pipe on a TURBO car will reduce flow. But I encourage anyone to tell me how say stuffing a rag in a garden hose will make the water flow better? And I know that water flow and air flow are two different things, but in simplistic terms, I think the analogy works.

And before everyone starts arguing about the need for backpressure for low end power, this is a turbo car, not NA. Also, if you want to talk about NA cars, great, but don't compare NA to Turbo cars for exhaust system concerns.

So now, tell me why the RS4 downpipes with 4 cats are better than any aftermarket downpipe with 2 cats?

Dangler {/KAWF} BUMP

is less than the amount RS4 dp's can flow. I doubt it, but...

The point it, there was a post a few weeks ago that mathmatically laid out how much flow is needed and how the AWE pipe flowed more than the max amount needed.

System_S4k

They will create quite a bit more exhaust gas over stock.

Dangler {/KAWF} BUMP

and then install a ****ing jet engine.

c'mon man, don't bust my *****. Someone needs to verify if "Mr. Math-magician" had the right numbers



just messin w/ you

System_S4k

hehe.

Dangler {/KAWF} BUMP

and went of on some **** i dont understand

System_S4k

I actually checked his math and it seemed to be right on. But I SUCK at math so that isn't saying a whole lot.
I had to get my dad who has an IQ of 160 somthing to come and help me. (flash backs of high school.)

Andrew C.

it's obvious. more is always better, right? 8^)

Singletrack

crap out of me in full Chief's uniform.

-st