i got an internal wastegate that is connected to a fitting coming out of the turbo.
if i connect the external wastegate to the vacuum manifold, can i leave the hole open on the turbo.

 

no, if you do not use the hole on the compressor outlet as your boost source you ned to plug it up air tight. If you leave it open you will have a boost leak. More then likely it is a 1/8 NPT port, so just get a 1/8 NPT plug with a little teflon sealant on the plug threads.

 

ok,thanks.

 

np, but on second thought you might wanna measure the hole. I have a 1/8 NPT adapter here and the diameter is 5/16" for the outer threads. Yours looks like it might be slightly bigger. If you have a 1/8 NPT fitting (doesn't have to be a plug) and try to screw it into the hole. That will tell you if you have the correct thread pattern or not.

 

If that's your turbonetics turbo then yes, its 1/8 NPT and you can get the plug at Lowes.

 

You might want to use that hole as the refrence point for the wastegate, using the manifold might cause overboosting or slow wastegate response.

 

thas not my turbo, thas just a pic i found. i got a garrett t3/t4. it has the fitting but i want to go to an external wastegate. cause with the internal the car is only boosting 2psi

 

Something else is wrong....

 

If you are only getting 2psi you have one of the problems below:

Major boost leak
broken actuator
bent actuator rod
malfunction flapper valve

Most likely it is the first one.

 

yea, sounds like a boost leak...

off topic but what kind of wg is that? looks killer