The "truth" about the 480 HP power figure?
Apparenly the VTG chargers produce so much heat, that Porsche wasn't actually ABLE to push the power figure above 480 HP without compromising the longtime reliability of the used technology. Keep in mind that Porsche tests their products under extreme conditions, so a tuned 997 Turbo may prove to be reliable even with high power figures...unless you drive it in the desert at +50*C temperatures. 
Tuning the 997 Turbo is no easy job, this is one reason why some Tuners are actually exchanging the VTG chargers with "normal" chargers. I don't know if this is THE solution, some Tuners managed to squeeze out "reliable" 550 HP out of the VTG charger equipped engine without compromising safety. Unfortunately, most tuning kits sold in the past are not really reliable or even safe but owners would probably never experience something bad because they don't live in regions with high temperatures and/or they don't driv the car for a prolonged time at extreme speeds.
I don't know if Porsche did that by purpose to "limit" Tuners from getting excessive power figures out of the 997 Turbo but anyone who is interested in tuning his 997 Turbo should be aware of possible problems and consequences.
Right now, any power figure above 550 HP using the original VTG chargers, can be considered "unreliable" and "unsafe". Of course the people I talked to didn't give or allow me to provide details but if you consider to tune your engine and if you want to stay on the safe side and if you don't want to heavily mod your engine, stick with power figures below 550 HP or so. As a general "rule", increased power figures in the 10-15% range should be fine. Anythin above that...your risk.
Tuning the 997 Turbo is no easy job, this is one reason why some Tuners are actually exchanging the VTG chargers with "normal" chargers. I don't know if this is THE solution, some Tuners managed to squeeze out "reliable" 550 HP out of the VTG charger equipped engine without compromising safety. Unfortunately, most tuning kits sold in the past are not really reliable or even safe but owners would probably never experience something bad because they don't live in regions with high temperatures and/or they don't driv the car for a prolonged time at extreme speeds.
I don't know if Porsche did that by purpose to "limit" Tuners from getting excessive power figures out of the 997 Turbo but anyone who is interested in tuning his 997 Turbo should be aware of possible problems and consequences.
Right now, any power figure above 550 HP using the original VTG chargers, can be considered "unreliable" and "unsafe". Of course the people I talked to didn't give or allow me to provide details but if you consider to tune your engine and if you want to stay on the safe side and if you don't want to heavily mod your engine, stick with power figures below 550 HP or so. As a general "rule", increased power figures in the 10-15% range should be fine. Anythin above that...your risk.
). The reliability "issue" is only an issue in Europe, where most of these cars are driven fast for prolonged periods of time. An occasional burst of full acceleration won't ruin your engine, that's for sure.
....suspect driving on fast, dense-traffic CA urban fwys (often in wrong gear while on phone and late to a mtg) reveals turbo lag/weak tq/slow shiftspeed issues fairly quickly.... 
