TVIS?

[jondee86]

The TVIS system increases the intake air velocity at low rpm's to
promote fuel vapourisation and cylinder turbulance. This gives
improved combustion, more torque and better low rpm acceleration.

After 4200 rpm the TVIS butterflys are open and the throttle area is
doubled for greater airflow at high rpm. But as can be seen from the
graphs, torque drops off at high rpm in a standard engine, meaning
that revving past 7000 rpm offers no performance advantage.. only fun

For normal street driving the TVIS makes the car pull stronger out of
corners and generally nicer to drive. Disconnect the vacuum hose to
keep the TVIS permanently open and compare, before you decide to
remove the butterflys.

Cheers... jondee86