wow your doing it way wrong. and the 05's have launch control from the factory.
first off there are only a few outcomes with launching
1. you do it right, you smell a tiny bit of clutch
2. you do it wrong and bog hard.
3. you do it way wrong and your buying new diffs.
WARNING: NEVER JUST DUMP THE CLUTCH ON A LAUNCH!
this is how i did mine and any other evo with launch control.
-Make sure your at a complete stop
-Push the clutch pedal to the floor
-floor the gas pedal
-watch RPMS raise and bounce at 5k (factory limit 05 evo and up, or to the RPM your tune is set for typically 6k to build 12-15psi)
-slowly let out the clutch until the car starts to move foward
-Once the car slightly moves foward slip the clutch fast
-Prepared for 2nd gear its coming fast
Disclaimer: If your car is not a drag car I would really rarely launch it, due to the extreme stress it puts on the drivetrain and if you mess up you are going to shell out a lot of money.