VTEC parameters

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VTEC window

The VTEC window is a variable VTEC switch point based on engine speed and engine load. The VTEC window allows the VTEC point to move higher with lighter engine load.

 

VTEC rpm window

vtec-rpm-window

The VTEC rpm window specifies the minimum and maximum rpm for VTEC activation.

 

Do not set the VTEC switch point too low as there will be insufficient oil pressure for the rest of the engine. As a guide do not go below 2500 rpm on twin cam engines, 1800 rpm on single cam engines and 1000 rpm for R18/R20 engines.
Do not set the VTEC switch point too high as the high speed rocker arm will float on the lost motion spring and damage the valve train. As a guide do not set the VTEC point higher than 6500 rpm.

 

VTEC window pressure

vtec-window-pressure

The VTEC pressure window specifies the minimum MAP for VTEC activation vs rpm.

 

See tuning VTEC

 

VTEC conditions

vtec-conditions

VTEC minimum coolant temperature is the minimum water temperature before VTEC will activate.

 

VTEC engage and disengage minimum speed is the minimum vehicle speed before VTEC will activate.  The disengage speed should always be lower than the engage speed.