Looking at a cutaway of the RS6 engine, it looks like there are a couple of restrictions on the stock downpipes. Also, I believe there are 4 catylitic converters.

Here are my questions.

Firstly, has anyone installed aftermarket downpipes (dp's) on their RS6. If so, did you notice or measure an increase in power. Which brand do you have and how much did it cost to install.

Lastly, is there any other benefit besides power. I am thinking maybe better fuel mileage, cooler engine bay, longer turbo life?

I know the B5 S4 stock dp's have precats right behind the turbos, and they get VERY hot, possible resulting in reduced turbo life.

Thoughts on any or all of the above are appreciated.

Thanks.