school me please

[Cleatus]

I just picked up a 95 GST that needs has the entire turbo system removed. The previous owner was an idiot who didn't know how to work on his car... I know very little about turbos and their setup...He removed everything related to the turbo from the motor, piping, intercooler, etc...He has a header installed that has the hole for the external waste gate welded shut. From what I know the guy has a 20G turbo set up for it with a waste gate built onto it...is this an external or internal wastegate?? like I said... I need schooled...can anyone please post up some links that will help me get this thing up and running again. I think it will need timed etc and I would like to run a boost controller but don't know if that requires an internal or external wastegate...

 

[thatblondechik]

Stock, your car comes with an internally gated t25 turbo. If he has the port for an external WG welded shut on your manifold, then you'll need to get another internally gated turbo.

The only reason you would need an external WG is if you're running 25psi+

The stock turbo for 1g's (the 14b) is a nice upgrade for all 2g owners and it's internally gated. You shouldn't need to "re-time" unless you're just talking about changing the timing belt (which really isn't a bad idea considering what you said about the previous owner).

 

[little-razcal]

I just picked up a 95 GST that needs has the entire turbo system removed. The previous owner was an idiot who didn't know how to work on his car... I know very little about turbos and their setup...He removed everything related to the turbo from the motor, piping, intercooler, etc...He has a header installed that has the hole for the external waste gate welded shut. From what I know the guy has a 20G turbo set up for it with a waste gate built onto it...is this an external or internal wastegate?? like I said... I need schooled...can anyone please post up some links that will help me get this thing up and running again. I think it will need timed etc and I would like to run a boost controller but don't know if that requires an internal or external wastegate...

If the wastegate is blocked off and the "20G" has a wastegate built onto it, then the "20G" has an internal wastegate. If the turbo didnt have a wastegate built onto it you would be running external wastegate from the manifold. To make things even more confusing for you, you can take the internally gated "20G" and make it non-functional by welding the flapper shut, then you can run an externaly gated set-up. You would then add an external wastegate (Tial being the most used) and be done. Really either way is fine. There are people running higher than 25psi internally gated. The main thing you need to do is get this sucker back together. Is this a stock intercooler? Front Mount intercooler? Do you have all the piping? Me personally, Id find some pictures of a 20G set-up on here and study it. Your turbo is going to be basically 4 bolts attaching it to the manifold. The main thing is making sure all your feeds are hooked up. Its not that hard. Keep researching and youll find what you need. As for the boost controller, it has nothing to do with what kind of wastegate you are running. Good luck

 

[jemsoccer]

If the wastegate is blocked off and the "20G" has a wastegate built onto it, then the "20G" has an internal wastegate. If the turbo didnt have a wastegate built onto it you would be running external wastegate from the manifold. To make things even more confusing for you, you can take the internally gated "20G" and make it non-functional by welding the flapper shut, then you can run an externaly gated set-up. You would then add an external wastegate (Tial being the most used) and be done. Really either way is fine. There are people running higher than 25psi internally gated. The main thing you need to do is get this sucker back together. Is this a stock intercooler? Front Mount intercooler? Do you have all the piping? Me personally, Id find some pictures of a 20G set-up on here and study it. Your turbo is going to be basically 4 bolts attaching it to the manifold. The main thing is making sure all your feeds are hooked up. Its not that hard. Keep researching and youll find what you need. As for the boost controller, it has nothing to do with what kind of wastegate you are running. Good luck

He hit all the high points. If you're looking at increasing boost w/ the boost controller, you'll need something to tune with. Don't just start twisting that little nob thinking you're making more power and not doing any damage. If you post up pics of what is and isn't there, we can help you figure out the missing pieces better.

 

[Cleatus]

thanks guys....I'm not dumb enough to "hey lets see what this does" and blow the motor..This may be my first turbo car but not by far my first motor repair/assembly....Google has so fare gotten me to the point I know I screw anything up too bad...but still a lot of learnign to be done.

 

[jemsoccer]

thanks guys....I'm not dumb enough to "hey lets see what this does" and blow the motor..This may be my first turbo car but not by far my first motor repair/assembly....Google has so fare gotten me to the point I know I screw anything up too bad...but still a lot of learnign to be done.

Haha, sorry. Didn't mean to imply you were dumb, but you never know who is asking the question and just wanted to make sure you didn't do something you'd regret.

 

[Cleatus]

Haha, sorry. Didn't mean to imply you were dumb, but you never know who is asking the question and just wanted to make sure you didn't do something you'd regret.

..NO prob...I know what you mean...I try to search for answers to my questions before I ask...google works but it throws so much info at you it tends to be all the same crap, just from a different website. I've learned the hard way way about adjusting stuff without knowing the consequences...Thank god they cheap fixes

 

[gofer]

I read through all these posts and they're missing a few things.

1. Just because your external wastegate port on the exhaust manifold is welded closed doesn't necessarily mean your still not externally gated. You can also run one off of the front o2 sensor housing. Below is a pictures of what it would look like externally gated off the o2 sensor housing...

External wastegate off of the o2 housing

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2. I don't know who started the rumor that you've got to be running an INSANE amount of boost in order to make an external wastegate effective, in reality its the EXACT OPPOSITE.

A wastegates job is to PRECISELY control an exact amount of boost your engine/turbo/fuel setup can support. An internal wastegate is very restrictive and can actually cause you to build more boost than you want, its called boost creep. An external wastegate is used because the opening on it is significantly bigger which allows it to redirect your exhaust to keep your turbo from spooling out of control. Essentially a wastegate is a NON ADJUSTABLE boost controller, unless of course you get a different spring for it.

3. A boost controller can be used on both an internal and external wastegate because they both work the same way and do the same job, the external just does the job BETTER .

Thats as far as I can go trying to put down on paper how things work in my head. If you want to read up and learn even more go here ---> How A Wastegate Works & Different Wastegate Options