Also a word of warning.
If you have removed the secondary throttle plates and you run up to the speed limiter you will lean out the motor.
The ECU closes off the secondary throttle as the first part of the speed limiter, it also cuts back the injector pulse time because it thinks the secondary plates are closed off.
If the plates are not fitted then the ECU has cut back the fuel but the motor is still getting the full amount of air, this will cause a lean condition that could damage the motor.
The second part of the speed limiter is to cut one cylinder, then two.