http://2009gtr.blogspot.com/2008/01/2009-gt-r-500-whp-with-exhaust.html Stolen from Erics - Beyond the Dyno blog Eric got it from the Option Magazine that Cosworth , and he are in. Eric doesn't seem to like the numbers that the Dynapack spits out at you. I have found that Dynojet, Dynapack read very similarly. He has spent a lot more time on the dyno than me , but I know what I have seen. 500 whp with an exhaust change is no joke. I did not think the ECU would allow the car to run higher boost, with changes like this. It seems like the all knowing , all controlling ECU is not as big and bad as Nissan said it was. I really don't like the look of this exhaust still. Who really needs 4 exhaust tips ? Works great for the Corvette guys , I want to see a true twin, or one big single exhaust. Add some mid-pipes , add some boost , and we will see 550 whp.