Go into PSA, open the Sonic PAC, on the top there should be a tab that say attributes (which I'm sure you already know). Change the Dash & stop initial to 5 or any high number, then change the Run initial velocity to 14, or higher. Scroll down to 0x088, it should have a 2.5, change this to 0.5. Then you're FINISHED!
If you want to make him faster, then go to BrawlBox and open the FitSonicMotion.pac. Scroll down to his Run animation, look for the TransN bone on the list to the left. Once you find it, look at your lower right and change the scale Z for that bone to 50! FINSHED!