So the ball-bearing option just makes the turbo spool faster and quicker, not earlier (on the lower RPM range)??? DarkOne said that he gets full boost around 4500 RPM, that's too long. I have an AT and I need more power around the low to mid range. I guess the smaller turbo gives you more low end grunt. I don't want to build the fastest car on the street or track, just wanted to have some zip around the town and occasionaly smoke Type R's, Rustang's, and Gaymaros.