my sx is smoking

some times my car puffs out white smoke and alot but its only sometimes. a jap import has just been put in and it hasnt been tuned yet but it smokes and ill turn off the car and turn it back on it wont smoke has anyone got any idea what the problem is

Turbo seals.

Yeah I agree with rat, the turbo seals are the most likely.

However, years ago I put in a Jap engine and it smoked really bad when I first ran it. Fearing the turbo seals as well, but far to poor to do anything about it I continued using the car. a week, +- 500km, later it just stopped smoking on its own. So never did find out what happened. A radiator failure a couple of years later rendered that engine useless.

any smokes from the car is bad! unless it from the tyres^^

Ye, i agree after modifying the exhaust my stock turbo seals also started smoking...sounds the same