doing this mod gives you faster spool up and lets you build 30 to 32 lb of boost... only down side is the stock turbo is only efficient up to 25 lb of boost..after that it just super heats the air and make EGT's climb faster..too much over boosting will shorten the life of the bearing in the turbo...on a stock turbo ..the back pressure is way off after 25 lb of boost to make a good balance for the wheels..