i have a mk4 gti and need some help with doing some upgrades to the motor. i want to pull some more power out of and was wondering if anyone knows if and what i might have to change on it if i were to put a bigger turbo on it. can i get a bigger turbo thats just a bolt on application or will i have to change a bunch of other crap with it?

 

APR.com will give you an idea of the cost and amount of parts.