Do you have to race super Sonic when you get seven chaos emeralds in Sonic R

No, when you get the 7 Chaos Emeralds you just have to press 'Down' at the 'Select Character' page on Sonic. The Super Sonic will appear. Only when you are unlocking the other characters(except Dr. Robotnik), then you will have to race with them and WIN. You must also be 1st when you collect the Chaos Emeralds to collect them.