to redirect the exhaust flow from the original flow to shorter exhaust flow.
So , like using straight piping without muffler la after the valve open coz the air will go through the new hole.
OK, as a Skyline owner, Im sure we all have encountered other cars on the road, either 'cucuk'-ing us (which is common if you drive a skyline!), traffic light drag race or even you 'cucuk'-ing them (cos lets face it...
To those who are familiar with fuel regulators, what is the ideal fuel regulator pressure for a 4G63? Currently mine is set to 30psi for 0.9bar. Is that too low/high?