From the STI owners manual:
"Setting the alarm-level engine speed"
Step 1 - Turn the REV setting knob clockwise or counterclockwise until the buzzer sounds. The REV alarm system is now ready to be set
Step 2 - Turn the REV setting knob to select the desired alarm-level engine speed:
Counterclockwise (-) turn: Speed setting changes downward in 100 rpm steps
Clockwise (+) turn: Speed setting changes upward in 100 rpm steps
The selected speed will be shown bythe outside temperature indicator. Appriximately three seconds after you stop turning the knob, the REV alarm system will automatically enter its next setting mode (step 3), in which you can enable or disable the buzzer.
The alarm-level engine speed can be set (in 100 rpm steps) within the range from 2000 rpm to 7500 rpm, the indicator shows the selected speed as follows:
Speed - 0: Indicator - 00
Speed - 2000 : Indicator - 20
Speed - 2100 : Indicator - 21
Speed - 7400 : Indicator - 71
Speed - 7500 : Indicator - 75
Step 3: To enable or disable the buzzer as desired using the REV setting knob
Turn the knob clockwise (+) to enable the buzzer. The indicator will show "ON". With the buzzer enabled, engine-speed warnings are given both by the REV indicator and buzzer.
Turn the knob counterclockwise (-) to disable the buzzer. The indicator will show "__". With the buzzer diabled, engine-speed warnings are given only by the REV indicator
Approximately three seconds after you stop turning the knob, the buzzer will sound once to indicate the end of the setting procedure. THe indicator will then revert to showing the outside temperature
DEACTIVATING the REV alarm system:
To deactivate the REV alarm system's indicator and buzzer functions, set the alarm-level engine speed to 0 (zero) rpm
THE REV ALARM SYSTEM DOES NOT OPERATE WHILE SETTINGS ARE BEING ENTERED
THE SPEED-SETTING MODE TERMINATES IF 0 RPM IS SELECTED
THE SPEED-SETTING MODE TERMINATES IF THE IGNITION SWITCH IS TURNED TO "OFF" OR THE VEHICLE STARTS TO MOVING BEFORE THE SETTING PROCEDURE IS FINISHED
SPEED SETTING IS IMPOSSIBLE WHEN THE VEHICLE IS MOVING.
End Quote !!!!!
THought this might clear it up..... Just to clarify when you are setting the rpm it is only the first two digits of the RPM that you want set that will display in the outside temp gauge ie 2500 rpm is dislaplayed as "25" in the temp gauge.
If anybody else would like info from the manual, let me know.