http://www.mkivsupra.net/vbb/showthread.php?33302-VVTi-A-discussion
you probably seen this link tho
i dont like the idea of this
Trac. The VVTi TRAC is too over-sensitive. Pulling the fuse will put the car into "snow" mode.
and MAF. The VVTi uses MAF, The MAF is far more accurate than a speed density system. The downside is that the MAF will eventually become a restriction if big power is required.
be easier if i pasted this lol
PRO's
ECU. The VVTi has 2 x 16 bit whilst the stock JDM is 2 x 8 bit. The ecu is obviously much faster. It is based upon the later Lexus units and is very powerful.
Fly-By-Wire. In conjunction with the ECU the FBY system will close the throttle if it senses detonation, high coolant temps, etc
The VVTi system. Adjusts the intake cam timing. This gives significantly more low end torque, and helps the larger turbo'd car spool earlier.
Rev Limit. The rev limit on a stock VVTi is 7200 rpm whilst the Stock JDM is 6800 rpm.
Neutral
MAF. The VVTi uses MAF, The MAF is far more accurate than a speed density system. The downside is that the MAF will eventually become a restriction if big power is required.
Inlet. The VVTi uses a smaller inlet manifold. This will improve torque, but may become a retriction on really big power cars ( 650+ bhp)
Cons
Wasted Spark ignition. This IMO is a step backwards to coil on plug.
Trac. The VVTi TRAC is too over-sensitive. Pulling the fuse will put the car into "snow" mode.
Engine Mounts. This applies to all Facelift cars. TMC changed the engine mounts for some strange reason. These are prone to failure and are not as "beefy" as those on earlier cars.