I need to know how to tell wheter a wastegate still usable,i found an old 40mm hks in my garage,dunno wheter still usable,if still usable i am not planning to buy one,i heard from friends that if the diafram is not good i cant use,any idea where is the diafram? And can i tell wheter it is still in good shape only by looking or any simple checking?

 

you can test it with a pressure souce such as a compressor. hook a hose to the pressure inlet of the wg. When it sees the spring rating it should open the wg and you can actually see the valve work.

you will need air compressor and regulator to control the amount of air and a hose.

 

besides that any easier way?BY looking or simple checking ?

 

You could remove the hat and look at the condition of the diaphragm. Other than that, flat mating surfaces, and overall condition, there isn't much to it.

 

How to tell the condition of the diaphragm is good any pics?

 

Make sure it still looks flexible. Inspect for cracks or tears and for brittle or hard spots. These are signs of a wastegate you want nothing to do with [unless you get it cheap and plan on replacing the diaphragm, if it's replaceable].

 

give up any idea is the turbosmart 35mm better or the hks 40mm