Most likely the alky is not even coming in at the brunout stage. You also have to remember that the system is "progressive". Even though it may start coming in early(5 psi) it is directly proportional to the MAp sensor voltage reading. The higher the boost the more alky is being injected. You should have no issues launching the car with alky injection. If you do, more than likely you are just to rich with fuel on the bottom end or have converter issues.
Juilo while chime in and tell you exactly whats going on.