they will be minimal, and you might suffer in the low end, but thats no biggy, you'll make up for it at the top.. its kinda a give and take with I/H/E, you usualy lose lowend and gain more power up high, and in the end the real world test gains you will get are minimal if that, but you will see some

ask her if you can grab some stickers too... they add 15+hp a peice
j/k, have fun with that exhaust, sounds great,, heard it once or twice...