2fast2furious movie question

When brian rolls up in his skyline in the first race.... what is the $hit that sprays out the side of the car...... is that just like displaced exhaust or sumtin.....

No, he was using a purge solenoid for his NOS kit so that the lines would be full when he was ready to engage nitrous. They're not necessary but mostly for looks and added effect all though they do serve their purpose by purging the lines.