i have a 02 duramax i just put 5 inch turbo back exhaust and im wondering what other mods i should do and if the 5inch was to big to put on

Welcome
You can start by looking here http://dieselplace.com/forum/forumdisplay.php?f=77

5" is definately not too big and I'm sure it sounds bad a**. Add a cold air intake and you'll hear the turbo much more. Letting it breathe (via exhaust & intake) is the best thing for the turbo. As far as power, it's endless. If you just want a good improvement over stock, add a basic programmer (0-90hp)and call it good. If you need more like most of us do, get a better programmer(0-200+hp) or look into EFI live(almost endless). An adjustable wastegate actuator will improve your boost by about 8-10 lbs depending on what you already can produce. If you do any major mods it is definately recommended that you get an egt and a boost gauge. Finally, the more power you add, the weaker your trans gets. The Allison 1000 in our trucks is programmed to only take a certain amount of power. After that, it is designed to "limp" itself thereafter. Too many limps and burnt clutches are the result. Most people here recommend doing a trans first, but it can be a bit pricey($3-5k). If you keep it on the mild side, you should be ok, but it's only a matter of time with larger amounts of power. Stick around and get your time in. The market place section here is bound to come up with what you're looking for. WELCOME!

yeh what do u think i should put for a intake and programmer i dont wanna make to much power just enough to play around with at the track

for an intake make your own i only spent 55 bucks for my intake its hope made its all stove pipe 1 45 degree elbow with a 28 inch peace of stove pipe and an autozome cone shape filter. As far as ponies with an edge juice with attuide u will be around the 14 range in the quarter mile. Everyone around here running the edge on there duramaxs is running 14.4 in the quarter. But u say u want a little something now but power get addictin u will want more and more u will never be satisfied