Hey ppl, iv been lurking in your forum for a while now, iv finally managed to get enough cash together to buy a wrx

I looked at one today and the guy said it needs a new turbo actuator, what i wana know is what exactly it is and what it does.

Also any other things to look out for ? the car is a K reg.

Thanks in advance

 

Hi mate

I reccomend doing a search for 'how a turbo works' or similar on google, I'll probably confuse you if I try and explain.

Basically the wastegate actuator is the device that opens the turbo's wastegate when the correct boost pressure is reached, this keeps the turbo from making more boost, it has to level off at the right amount (depending on car, std, modified, etc, etc), for example the standard k reg wrx may have a boost target of 0.80bar, when the turbo spins up enough to create this level of pressure to the engine, a pipe from the inlet manifold to the actuator will have the amount of pressure in it, the actuator will(when boost target reached) open the wastegate and level the boost off at it's target of 0.80bar.

This above is only an example as, the boost pressure on a k reg wrx is attained using a 3 port boost solenoid controlled by the ecu, in my example a pipe directly from inlet to actuator would see around 0.60bar(actuator cracking pressure), the solenoid effectively bleeds off air and allows less boost to the actuator therefore allowing the wastegate to open less, hence 0.80bar...

anyway, as I said best do a search, as I've probably confused the issue.

Be careful though when buying the car you talk of. To be honest there isn't a lot that can go wrong with an actuator. They are very simple mechanical devices.

Ask the guy; why does it need a new actuator?, Is it not producing enough boost?, Is it producing too much?, How does he know?

To be honest it probably is another problem with the car (depending on why he thinks it needs a new actuator)

 

Thanks for the reply, i do understand what your saying, aparently its 'sticking' he says it will cost about £50 to replace, this sound about right ?