No no don't worry I'm not going to ask "which exhaust is best???/?"

I was wondering is it beneficial at all to replace the stock exhaust manifold and cats with a header and downpipe or presilencer, without replacing the Y pipe and mufflers?
Or if I do decide to get a header and downpipe/presilencer/high-flow cat do I also need new Y pipe and mufflers for it to have an discernable effect?

And as far as stock power goes, I have an S4 NA and was wondering if anyone knew or had dyno papers from what kind whp and torque they put out in stock form with no modifications.

 

i just got back from getting my exhaust noise measured (ticket)

90.6db-- racing beat header and presilencer w/ stock y-pipe and mufflers.

95db is the limit... so your safe if you go that route.

as far as power goes, i dont know- i'll be getting my corksport on the 20th so ill let you know if there's a difference on the butt dyno. Its going to be a bit louder than 95db though