try lower my boost setting, it doens't work. finally removed the vacum hose off my wastgate, figure the wastegate will open after 10lb of boost, since i have the 10psi spring. guess what?? it didn't open at all, i saw as much as 16lb before i let off the gas. does it sound like my wastgate ? or it could be something else?

 

just out of curiosity, what type of wastegate are you using?

 

If you disconnect the hose to the wastegate, it's not going to open at all!!! Never do that!!! One time I forgot to attach the wastegate hose back and I was boosting 25 psi on pump gas. My car went from 0-90mph in about 4 sec and the engine only lasted those 4 sec as well.

Chuck Huang

 

umm ya a wastegate will always stay shut if the pressure line from the the compressor side of it isnt attaced or from your boost controller. what happens is that line has a pressure in it when it builds 10 psi in it pushes that spring and diaphram down and opens the wastegate letting some exhuast bypass the turbine and flow straight into the exhaust

 

But if you pull the correct hose off of the wg and leave the other on, you will get the wg spring pressure -I'm hoping thats what he did.

 

there is only one hose on a waste gate so if you pull loses the pressure that opens it to control boost pressure

 

there are two hoses, the one i pull is for the vacum back to the boost controller. I'm sure i pulled the right one. either way, i still see more then 10lb of boost. I'm running the hks wastegate, it has a 10lb spring. should the wastegate open after 10lb?

 

sounds like your working on an fd never worked on one of those so i dont what the turbo assembly looks like or how it works with the twins

 

Dude, he just said he has an HKS wastegate. He could be working on a Mack truck with one -they're all the same. To answer his question, yes, you should be getting spring pressure by pulling that line. Check and see if the signal line from the compressor is burned or torn. Otherwise check the wastegate diaphram.

 

I hear ya..........

 

Which HKS wastegate do you have? standard, racing or gt?

I've seen standard ones with sticky diaphram. Usually when they are still new, wastegate line kinked/leaking, the internal wastegate spring was somehow jammed (I’ve seen it before) or some **** just somehow got stuck in there...

Do this. Connect a high pressured compressor on the wastegate hose/nipple. Blow the pressured air through it, and listen for "clicks". If you hear a "click", that means your wastegate diaphram is opening and shutting - assuming it's opened all the way. Sometimes, you can still hear the click sound, but there is no way you can tell if its opened ALL THE WAY). Your best bet is to remove the wastegate entirely from the manifold and watch it open and shut.

 

i didnt see the post on the hks wastegate my bad but i dont know anything about the stock twins which i thought he was using i dont know if theres 2 wategates or not, but if you disconnect the vacuum line that goes to the wastegate it will not open at all it will always keep the wastegate shut and all exhaust gas will go through the turbine making the turbo create extreme boost pressures.

 

The stock FD wastegate actuator has two nipples but they both go to the same chamber.

External watsegates have two nipples, but each one goes to a different side of the diaphragm.

 

My recommendation would be to pull the wastegate and test with a pressure/vacuum tester he can get at Sears or Pep Boys. Make sure you pull the wastegate off the car as this is really the best and easiest way.

It sounds like it is stuck.

regards

Rick

 

that's what i though too rick , thanks for your help, we need to meet up again soon. take care