Motor VVTI

Look closely at how the exhaust gases pushes back into the intake 0.02

LOL i c that

VVTL-i is combined system,
i expect it was not very good, it will allow too much flame to flow out of the combustion chamber, may cause pre-ignited, loose of power, that why the BMW E90 320Si had removed the valvetronic (in N45b20s engine) and just use double vanos to defeat HONDA latest VTEC in FIA-WTCC.

it was similiar to BMW VANOS,
the exhaust valve close early to trap some expanded flame/hot air in combustion chamber, then with intake valve open early allow the flame/hot air (flame/hot air is lower pressure than cooler air when finish burning, create higher vacuum pressure) suck the cold air into the cylinder by the vacuum pressure, the main objective was to improve the vacuum pressure in the combustion chamber during sucktion cycle.

actually part of the exhaust contain unburn fuel, CO, NOx (nitrogen oxide),
those chemical combusted with air and fuel ratio will reacts like plenty of NOS injection. NOS aka nitrous oxide -> nitrogen oxide, was preduce in some quantities in every air/fuel mixture combustion, the nitrogen in air react with oxigen.,

exhaust and air with Fuel equal Carbon monoxide, Carbondioxide and Lung system toxic gas.
HP is UNERAL.
SOUND IS UNREAL. Because sound of engine effect only air fitter and exhuast.

Lie

RAMA 4 university have been fail EU Exam.
WHY SHOULD TRUST Thier mechanic.
.

Piston never hit the valve.
Because piston stroke : camshalf is 2:1.