Ha, yes indeed meticulous documentation is the engineer's way, however we are excellent cheapasses, too. As such I will not do the dyno before and after. But if you really want to see the gains you can do some hunting on this forum and 986forum.com. All the dynos are there, in different combinations. One for just intake, one for just headers, one for just exhaust, and one for all 3. You can find them for the 2.5L and for the S. Note that they are end-user dynos and not some bs made up by the parts mfr.

 

Doing the bolt ons first is a very good decision to start with. As info, significant dyno work was done on my car with several different exhaust systems and very little, if any, increase in power was observed using after market exhausts VS the stock S exhaust. On the ones with increases, the power was observable only at very high RPM. Header systems do provide good results, so I went with headers and put the stock exhaust back to get rid of the drone at highway speeds. The overall sound now is not great except under hard acceleration, so I am still looking for an alternative. The Fabspeed sounded great under power, but the drone was just not acceptable to me at the time. The PSE actually showed slightly reduced power. The weight loss of the Fabspeed and the sounds at speed would make it worth the cost if I didn't drive the car on the interstate a lot. The drone just drives me nuts right in the 55-75 MPH range in 6th. IT was great driving that same speed in 4th, but mileage went to about 15. The light weight flywheel is noisy when the clutch is disengaged, and is hard to get used to off the line, especially on hills, but the extra throttle response is worth the downsides, plus it keeps my wife from driving the car ever. She can't deal with the clutch anymore.

 

Installed headers, exhaust and cold air intake. Not sure about power gains but the noise is unbeatable. As soon as you put your foot down, the now gaping-wide intake rumbles and inhales air like an african lion after the hunt. But that only last's a fraction of a second before the exhaust pounds out an intoxicating brew of drum beats on the low end and gunfire up top. And all these sweet noises are not just what you hear, but also what you feel. The car feels snappier, more responsive, more aggressive. Truth be told, I have no idea if it gained any of those things, but it matters not, since ultimately it is the feel of the car, not it's numbers that can make it truly great.

Total price: $630 and worth every penny.

Let me just say, I am exceedingly glad I did not sell my car and upgrade to the S, and this is why. I drove the S model before upgrading my Base, and honestly, I could barely tell if there was a difference in power between the two. Now that I have modified my Base, it feels 60% faster than the S I tested. Now I am not saying that the S isn't faster. Of course it is quicker than the base, BUT, I would have had to do the exact same modifications to be able to enjoy the car like I enjoy mine. With these modifications on my Base, I would not upgrade to an S(unless it had the same!). So in summary, I saved a couple of thousand dollars, and retained my low mile car with the options that I want. That being said, someone else's milage may vary. For example I would imagine that the raw increase in hp between the Base and S is much more important than the "feel" of the car to someone who is into tracking. But for me and my mods, well, we are a match made in gearhead-heaven.