I've had these headers laying around for quite a while, and finally got a chance to get them installed and on the dyno.
I bought them second hand from another forum member. PPE headers are normally mild steel, but these were special ordered as stainless and ceramic coated. Then I had them wrapped with DEI Titanium wrap.
Pic of the headers after wrapping and before install(linked for hugeness)
Before and after dyno chart
Before: Stock
After: PPE Headers + UpRev tune
RunFile_005.drf: 86.47 °F 28.68 in-Hg Humidity: 46 % STD: 1.07
RunFile_019.drf: 68.51 °F 29.16 in-Hg Humidity: 30 % STD: 1.03
Final pulls done in 5th gear. These things showed decent gains across the board with peak gain of about 35WHP!!!
The pull in the vid was just in 3rd gear for tuning purposes.
As far as sound, I usually don't care too much about that sort of thing as long as it's not obnoxiously loud. I did notice a bit of rasp on cold starts, but seems to get better as the engine warms up. Standing oustide of the car during a pull, it was not too terribly loud, quieter than I expected actually. Of course I still have stock catback in place.
Before getting it on the dyno I was hoping for +20HP or so, though in the back of my head I thought maybe that was a bit optimistic. Needless to say these headers have far exceeded my expectations. The quality of fabrication and engineering that went into these headers is top notch, and I would recommend them to anyone else looking for the best for their car. Props to PPE for an awesome product.