This may seem to be an odd question, but is it possible to get good gains by getting a cam and headers while retaining the stock muffler? The reason I ask this is because I want my car to remain fairly quiet, yet be blazing fast at the same time. I have to drive my car a lot for work and a really loud exhaust gets old pretty fast when you are in the car all day. Besides, I like the idea of a sleeper anyway! Basically, how much rwhp could I get with stock exhaust? Keep in mind I have an A4 as well. Thanks!

 

Yes you can keep the stock muffler with headers, but if you have headers it is going to be a little louder, esspecially if you kill the cats too. And depending on how aggressive of a cam you want you might be able to tell it is cammed too.

But to your average ricer who has 200hp in a wing they would probably never relealize what you had.

 

It sounds like you're probably best off to get a custom y-pipe with dual cutouts behind each header. That way you could retain the stock exhaust for daily driving and open up the cutouts for when you want to tear up the track/street. To make things a little easier, you could even go with electric motors on the cutouts so all you'd have to do is flip a switch and they're open.

 

02 Z06 cam
Hooker LTs
SLP 1OTL (replace tip with something understated, or tuck it away like a V6 car)
Dynomax 24222 in I-pipe
No cats
TC
3.42 gears
Aluminum driveshaft
Subframe connectors
Computer tuning
Lid
FRA
Free mods (no MAF mods though!)
If you want a little extra 'sleep', take the Z emblems off the car.
This is your recipe...
Good luck
Dave