Wastegate question
Thread Starter
Drifting
Joined: Sep 2005
Posts: 1,788
Likes: 2
From: Tallahassee FL
Wastegate question
The other day I cracked open the STS manual to check on a wiring problem I am tackling, and the first pic I see is of one of the turbo wastegates. There is a bolded notice there stating
Hmm, seemed to me that I recall looking at the wastegates on my car and they didn't appear to have those ports open. So I went over and checked them out.
Double hmmm.....
The manual doesn't really say anything about what would happen if they are NOT vented to atmosphere, but it does say that applying boost pressure to that Rear Vent Port and/or not applying boost pressure to the Front Boost Port will cause the wastegate to stay closed and the turbo to over-boost.
Sheesh.... Great....
I sent STS an email to get their take on this situation but perhaps maybe someone else in here has any idea about whether this is a problem or not and I can either start doing something about clearing out those ports, or just stop worrying about it.
The Rear Vent Port on the wastegate must be vented to atmosphere.
Double hmmm.....
The manual doesn't really say anything about what would happen if they are NOT vented to atmosphere, but it does say that applying boost pressure to that Rear Vent Port and/or not applying boost pressure to the Front Boost Port will cause the wastegate to stay closed and the turbo to over-boost.
This will cause IMMEDIATE SEVERE damage to the vehicle's engine!
I sent STS an email to get their take on this situation but perhaps maybe someone else in here has any idea about whether this is a problem or not and I can either start doing something about clearing out those ports, or just stop worrying about it.
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 78
From: Forney Texas
Remove the bolt from the top center, remove the banjo style barbed fitting, drill and clean it out. Neutral pressure is needed on that side of the diaphragm. There is a spring pushing the gate closed and the boost pushes against the diaphragm on the other side. It needs to be clear in order to properly control boost.
Boost control systems will use that side to create a pressure differential and allow boost to go beyond the spring pressure.
Boost control systems will use that side to create a pressure differential and allow boost to go beyond the spring pressure.
Last edited by BLOWNBLUEZ06; Apr 21, 2012 at 07:10 PM.
Thread Starter
Drifting
Joined: Sep 2005
Posts: 1,788
Likes: 2
From: Tallahassee FL
Remove the bolt from the top center, remove the banjo style barbed fitting, drill and clean it out. Neutral pressure is needed on that side of the diaphragm. There is a spring pushing the gate closed and the boost pushes against the diaphragm on the other side. It needs to be clear in order to properly control boost.
Boost control systems will use that side to create a pressure differential and allow boost to go beyond the spring pressure.
Boost control systems will use that side to create a pressure differential and allow boost to go beyond the spring pressure.
Now, what would be the results of running the car under boost with the wastegates having those ports plugged in this manner? If those are 10 lb springs in the wastegates, how much boost, approximately, would they allow the turbos to spin up to?
And is there any good reason why someone supposedly versed in turbochargers would have plugged those vents?
Oh yeah, can I reuse those crush washers, or do I need to get new ones?
Thread Starter
Drifting
Joined: Sep 2005
Posts: 1,788
Likes: 2
From: Tallahassee FL
Thank you.
Now, what would be the results of running the car under boost with the wastegates having those ports plugged in this manner? If those are 10 lb springs in the wastegates, how much boost, approximately, would they allow the turbos to spin up to?
And is there any good reason why someone supposedly versed in turbochargers would have plugged those vents?
Oh yeah, can I reuse those crush washers, or do I need to get new ones?
Now, what would be the results of running the car under boost with the wastegates having those ports plugged in this manner? If those are 10 lb springs in the wastegates, how much boost, approximately, would they allow the turbos to spin up to?
And is there any good reason why someone supposedly versed in turbochargers would have plugged those vents?
Oh yeah, can I reuse those crush washers, or do I need to get new ones?
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 78
From: Forney Texas
With the small turbing housings on the STS kits, I would I would expect them to possibly spin up until the back pressure is so great that they are unable to climb any more due to choking the car, but I've seen wastegates not open and push ridiculous enough boost to burn traces across the cylinder head and head gasket. There's just no telling, but there's not many good scenarios there.
No reason at all that I can think of to do what was done there.
You should be able to reuse the washers.
No reason at all that I can think of to do what was done there.
You should be able to reuse the washers.
