How many HP will I get if i add a turbo down pipe only to my 2006 Subaru WRX

IT DEPENDS ON WHICH TURBO DOWN PIPE IT IS AND ON THAT CAR DEPENDING ON HOW MUCH HP IT'S PUSHIN PLUS ON THIS 2006 THE MOST YOU CAN GET WITH OUT OVER POWERING THE CAR IS 760 HP IF YOU WANTED,TRY SOME FUEL INJECTORS TO HOLDS BACK AND IT'S LESS SPRAY,AND AN HIGH POWER EXHAUST WILL DO YOU WELL A DNX EXHAUST HIGH POWER ONES ARE THE BEST AND TRY PERFORMANCE MOTOR OIL TO FROM GREDDY,BUT T-66 TURBOS HAVE BEEN A FAVORITE OF MINE

l believe that it is something like 10 to if you get rid of that catalytic converter that is a part of the stock down pipe.
it will also make your car fail any smog check if you have them where you live.

'' l was told that each sticker on you car is good for 5 HP''

l would look at the dyno results that the manufacture could give you, because without that your just guessing.

it will help and it will sound different but as far as hp l would guess 10-14.. the hold turbo back is whats going to help you get like 70hp

10-15 (whp) depending on style (bellmouth/divorced wastegate/ flat flange). However it should be noted that with the open/closed fuel delay you will need some form of engine management to properly run an aftermarket downpipe. Engine management plus a downpipe is worth 40-50 (whp) a little more if you add a cat-back to form a complete turbo-back exhaust.