Ok, my wastegate is set at 7 psi. But for some reason I got more than that on my test runs this morning.
I originally thought it was the wastegate not getting a clear enough signal, so I welded a hose into the intake pipe after the turbo. Sure it's not the best place. But I know that it has a clear signal now. I'm not 100% sure it is opening yet though. I mean it has to be getting boost signal, so it should therefore open. The line is on very tightly.. It's an internal.. I'm thinking of taking off the hood and driving down the road and see if she will open or not. Just so I can know if it is or is not the problem.
Now here is what I think the problem is. I think that my bypass valve is not getting a clear signal (it's plugged into the vacuum tree behind the intake manifold.. the one that comes out from just under the intake runners; it's the same line my boost gauge is from). And I think my wastegate is opening. So when it gets on the boost it sends part of it to the motor but the rest of it goes round and round spooling through the unclosed bypass valve. The internal wastegate opens, but the exhaust can still go through the turbine. So I think it opens up but it is so easy for the turbo to just spool itself that the wastegate isn't performing it's task. And that is why I am getting such high boost levels.
Of course if the wastegate isn't opening then I have a problem I have no idea how to analyze.
Sorry that was a long post.. I am just looking for some help on this. I'll go crazy if I have to troubleshoot every possiblity on my own
Thanks guys
Over boosting problem
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C-Kwik
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I'm not sure what you are saying you think is occurring. If by bypass valve you are talking about a blow-off valve, then it has nothing to do with overboosting.
Overboosting usually happens for two reasons. A wastegate that is not opening or at least not opening enough. Or the wastegate is too small to divert enough air. At 7 psi and from what you are describing, your wastegate is not too small. The wastegate may be sticking. Easiest way to test this is to run a short vacuum line from the wastegate actuator to a pump that has a gauge. You'll need to make sure the connection is secure and airtight, but you will want to put positive pressure to the line. You'll want a gauge to be inline so you can monitor pressure. If you have a 7 psi wastegate, it will start opening a little before 7 psi. You should be able to see the actuator arm start to move. If it moves later, there is something wrong, or the wastegate is not actually a 7psi wastegate. Which actually brings me to my next point. How is the wastegate "set" to 7 psi? You're not assuming it will be 7 psi becuase you are using a boost controller are you? Boost controllers only allow you to increase boost, not decrease it.
Overboosting usually happens for two reasons. A wastegate that is not opening or at least not opening enough. Or the wastegate is too small to divert enough air. At 7 psi and from what you are describing, your wastegate is not too small. The wastegate may be sticking. Easiest way to test this is to run a short vacuum line from the wastegate actuator to a pump that has a gauge. You'll need to make sure the connection is secure and airtight, but you will want to put positive pressure to the line. You'll want a gauge to be inline so you can monitor pressure. If you have a 7 psi wastegate, it will start opening a little before 7 psi. You should be able to see the actuator arm start to move. If it moves later, there is something wrong, or the wastegate is not actually a 7psi wastegate. Which actually brings me to my next point. How is the wastegate "set" to 7 psi? You're not assuming it will be 7 psi becuase you are using a boost controller are you? Boost controllers only allow you to increase boost, not decrease it.
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PMan_S13
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Well I had a manual boost controller installed.. but once I had this problem I took it out of the system to make it simpler until I could find out what is wrong.
By "set" I mean that the spring in the internal wastegate is for 7 psi.. it's the spring that I ordered for it when I got the turbo.
I do have a bypass valve. A recirculating bov. I think this is still a possibility. I mean the by pass recirculates back in front of the turbo.. the turbo could just keep pumping and sucking it's own boost right back in. See what I mean? BTW, in case it matters.. I have my bypass installed just infront of the TB and the pipe feeds back to the intake just before the compressor.
So you think it could be something wrong with the wastegate opening? I did test it with a air hose but I didn't check what the pressure was at the time. I just wanted to make sure it opened.
Is there a chance I could be having vacuum leaks? Or boost leaks actually.. could that cause these types of problems?
By "set" I mean that the spring in the internal wastegate is for 7 psi.. it's the spring that I ordered for it when I got the turbo.
I do have a bypass valve. A recirculating bov. I think this is still a possibility. I mean the by pass recirculates back in front of the turbo.. the turbo could just keep pumping and sucking it's own boost right back in. See what I mean? BTW, in case it matters.. I have my bypass installed just infront of the TB and the pipe feeds back to the intake just before the compressor.
So you think it could be something wrong with the wastegate opening? I did test it with a air hose but I didn't check what the pressure was at the time. I just wanted to make sure it opened.
Is there a chance I could be having vacuum leaks? Or boost leaks actually.. could that cause these types of problems?
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PMan_S13
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Ok, here's what has happened since my last post.
I checked the wastegate with a pump.. it starts to show movement at about 5 psi and by 7 it is all the way open and has hit it's mechanical stop. So that should not be a problem.
I redid the vacuum tree that connects my boost gauge, bypass valve, and whatever else it runs off into (It goes underneith the intake runners) so that all the connections are very tight. So that should no longer be a problem.
I took off the bypass valve (bosch) and inspected it.. no tears, to clogs, looks good. Reinstalled it. Should not be a problem*
So I took it out for a test run. Waited till 3rd and a clear road to try anything. The wastegate is working now without a doubt. I gave it some gas and the boost hung around 5-6. So I kept testing. Gave it some more gas and let it go up the gear.. once it gets past like 4500 the boost gets higher. I let it top out in 2nd.. 11 psi was the max.
Now I was planning on running 10psi anyway so I wasn't worried about hitting it.. but I should not be hitting it with this wastegate. I am calling the shop I bought my turbo from to make sure this is definately a 7 psi internal wastegate. But if it is, what could the problem be? Even though I plan on running this amount of boost, I don't like the fact that I am not in control.
* I am thinking that the bosch, which is probably the lowest grade bypass/bov, it not capable of keeping up with the amount of air I am flowing. After all it is just a simple rubber and plastic valve.
I checked the wastegate with a pump.. it starts to show movement at about 5 psi and by 7 it is all the way open and has hit it's mechanical stop. So that should not be a problem.
I redid the vacuum tree that connects my boost gauge, bypass valve, and whatever else it runs off into (It goes underneith the intake runners) so that all the connections are very tight. So that should no longer be a problem.
I took off the bypass valve (bosch) and inspected it.. no tears, to clogs, looks good. Reinstalled it. Should not be a problem*
So I took it out for a test run. Waited till 3rd and a clear road to try anything. The wastegate is working now without a doubt. I gave it some gas and the boost hung around 5-6. So I kept testing. Gave it some more gas and let it go up the gear.. once it gets past like 4500 the boost gets higher. I let it top out in 2nd.. 11 psi was the max.
Now I was planning on running 10psi anyway so I wasn't worried about hitting it.. but I should not be hitting it with this wastegate. I am calling the shop I bought my turbo from to make sure this is definately a 7 psi internal wastegate. But if it is, what could the problem be? Even though I plan on running this amount of boost, I don't like the fact that I am not in control.
* I am thinking that the bosch, which is probably the lowest grade bypass/bov, it not capable of keeping up with the amount of air I am flowing. After all it is just a simple rubber and plastic valve.
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PMan_S13
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cool.. so I just need to take off the downpipe, and then unbolt the flange to the internal wastegate, and unbolt the mount to the wastegate itself... then it can swivel to where I can get a dremel in there. How big am I gonna want it? And what side affects am I looking at besides boosting a little later
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PMan_S13
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Hmmm.. I am beginning to think that all these problems I have been having are all related.
Here is a list of all the things not working for me 1.Wastegate should be opening at 7psi, I am boosting 102.Boost gauge is not responding quickly, especially on vacuum. It does respond alright on boost, but on vacuum it takes forever to settle into an accurate reading. I tested the gauge itself. It seems to be accurate and responsive. So I can only assume it is something with the vacuum lines which would mess up anything that needs to read vacuum/boost.3.It is having some trouble starting sometimes. Helps if I give it some gas4.Trouble idling. (Everyone does though I think. And it never idled the best, even when it was non turbo)
I think these are all vacuum related problems. I have tried everything I can think of to check for leaks; starter fluid, water, pressure test, physical inspection. Nothing seems to be leaking.
I don't think I could show how lost I feel right now.
Here is a list of all the things not working for me 1.Wastegate should be opening at 7psi, I am boosting 102.Boost gauge is not responding quickly, especially on vacuum. It does respond alright on boost, but on vacuum it takes forever to settle into an accurate reading. I tested the gauge itself. It seems to be accurate and responsive. So I can only assume it is something with the vacuum lines which would mess up anything that needs to read vacuum/boost.3.It is having some trouble starting sometimes. Helps if I give it some gas4.Trouble idling. (Everyone does though I think. And it never idled the best, even when it was non turbo)
I think these are all vacuum related problems. I have tried everything I can think of to check for leaks; starter fluid, water, pressure test, physical inspection. Nothing seems to be leaking.
I don't think I could show how lost I feel right now.
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PMan_S13
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Ok, I have most of my issues resolved... 2,3 (not perfect but much better), and 4 if you read above.
I am going to port out my internal wastegate with a dremel tool. Any advice? Should I port it out so that some gas is always being gated? (Like making the hole bigger all the way through.. but this would hurt spool time) or port it out like a funnel so the gate can still close fully and divert all exhaust gas through the turbo?
I am going to port out my internal wastegate with a dremel tool. Any advice? Should I port it out so that some gas is always being gated? (Like making the hole bigger all the way through.. but this would hurt spool time) or port it out like a funnel so the gate can still close fully and divert all exhaust gas through the turbo?
We had a problem with a car that was boosting to one bar when it was supposed to be set to half bar. It turned out to be the boost controller vacuum box. As soon as we disconnected the WHOLE controller system it ran like a champ. The guy who had it bought it used though so I don't know if it applies here.
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PMan_S13
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Well I had a manual boost controller on so I could turn up the boost from 7 psi. But since it was overboosting I took it off to get rid of a variable till I could fix it.
I'm pretty sure this is just a problem with the wastegate not being able to vent enough. Actually is there anyway I can test this? I'm thinking of taking off my hood and driving up the road to see when the wastegate opens. It has to be working correct though.. the wastegate actuator line is plugged directly into the intake.. it should be very responsive, although not accurate because of pressure drop after the spot it' plugged in
Any help with the porting issue in my previous post? I'm doing it tomorrow once I get off duty, or at least I plan to
I'm pretty sure this is just a problem with the wastegate not being able to vent enough. Actually is there anyway I can test this? I'm thinking of taking off my hood and driving up the road to see when the wastegate opens. It has to be working correct though.. the wastegate actuator line is plugged directly into the intake.. it should be very responsive, although not accurate because of pressure drop after the spot it' plugged in
Any help with the porting issue in my previous post? I'm doing it tomorrow once I get off duty, or at least I plan to
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C-Kwik
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I don't think the wastegate should have problems controlling 7 psi. What type of downpipe flange are you using? Make sure it's not causing any disruptions to airflow behind the flapper.
Also, where is your wastegate signal coming from? The manifold? The compressor housing? Intake piping? I'd try sourcing a signal from the compressor housing outlet if possible. Is the boost spiking briefly to 10 psi or is it hovering up there? A signal off the manifold is more prone to boost spikes. Especially if the wastegate actuator is slow in responding.
Also, where is your wastegate signal coming from? The manifold? The compressor housing? Intake piping? I'd try sourcing a signal from the compressor housing outlet if possible. Is the boost spiking briefly to 10 psi or is it hovering up there? A signal off the manifold is more prone to boost spikes. Especially if the wastegate actuator is slow in responding.
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PMan_S13
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Well I'm not really sure what you mean by downpipe flange.. I thought there really would be only one type. It's shaped like a curved triangle and looks pretty unobtrusive to me.
Originally I had the wastegate signaled off the manifold but I was having vacuum nightmares so I welded a little bung in the first pipe out the compressor and plugged it into that.. It's about 6 inches down stream of the turbo.
It is holding at about 10 or 11 psi in the upper rpms.. but it isn't all that stable so it's hard to be sure.
I have the wastegate flange off the turbo now so I can get at the wastegate port.. it doesn't seem all that small to me. Maybe about a quarters width all the way through. The flange itself is only about 1/2" thick. Not really sure why it isn't functioning properly. But tomorrow morning I'll go ahead and port it out as best I can. Not gonna hurt anything anyway.
I think once I get it put back together I'm gonna take off the hood and be 100% sure that the wastegate is opening all the way.
Originally I had the wastegate signaled off the manifold but I was having vacuum nightmares so I welded a little bung in the first pipe out the compressor and plugged it into that.. It's about 6 inches down stream of the turbo.
It is holding at about 10 or 11 psi in the upper rpms.. but it isn't all that stable so it's hard to be sure.
I have the wastegate flange off the turbo now so I can get at the wastegate port.. it doesn't seem all that small to me. Maybe about a quarters width all the way through. The flange itself is only about 1/2" thick. Not really sure why it isn't functioning properly. But tomorrow morning I'll go ahead and port it out as best I can. Not gonna hurt anything anyway.
I think once I get it put back together I'm gonna take off the hood and be 100% sure that the wastegate is opening all the way.
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C-Kwik
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Well since the actuator was fully open by 7 psi, the actuator sounds like it's fine. It's got to be a flow issue, but I'm not convinced it's the port.
The possible issue with the turbine to downpipe flange is that it may be blocking airflow behind the flapper door. Just make sure there would be sufficient room for air from the flapper door to rejoin the air coming out of the turbine. I'm just considering any possibility since I haven't seen your set-up. If you get a chance, post some pics. It might help us to help you.
The possible issue with the turbine to downpipe flange is that it may be blocking airflow behind the flapper door. Just make sure there would be sufficient room for air from the flapper door to rejoin the air coming out of the turbine. I'm just considering any possibility since I haven't seen your set-up. If you get a chance, post some pics. It might help us to help you.
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PMan_S13
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Well I got my new and better bypass valve. It's installed now. Vacuum is still good..
I ported out my wastegate yesterday for about 30 minutes with a dremel. I took a good bit out but it's still acting exactly the same. No difference in boost lag, spool, anything.. I would think it would be at least slightly noticable. The way the wastegate was designed it looked like the exhaust flow had to change directions completely to come out the port. (Had to bounce off the turbine and then double back to get out the port) I took the entire edge off of it so the airflow could come straight out. But it seems to have been a wasted effort.
It looks like there would be plenty of room for air to flow out and rejoin the exhaust flow to me. It does have to make two small 90 degree turns to get out of the flappers way and then get into the downpipe.. but the overall distance is much much shorter than going through the turbine.
I'm gonna see if I can borrow my buddies camera, I don't think I can explain any better...
I ported out my wastegate yesterday for about 30 minutes with a dremel. I took a good bit out but it's still acting exactly the same. No difference in boost lag, spool, anything.. I would think it would be at least slightly noticable. The way the wastegate was designed it looked like the exhaust flow had to change directions completely to come out the port. (Had to bounce off the turbine and then double back to get out the port) I took the entire edge off of it so the airflow could come straight out. But it seems to have been a wasted effort.
It looks like there would be plenty of room for air to flow out and rejoin the exhaust flow to me. It does have to make two small 90 degree turns to get out of the flappers way and then get into the downpipe.. but the overall distance is much much shorter than going through the turbine.
I'm gonna see if I can borrow my buddies camera, I don't think I can explain any better...
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WAbernethy
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Yesterday my CT26 made almost 15lbs of boost. Luckily, I heard the turbo spooling much higher than normal checked the gauge and let off the gas before any damage was done. My wastegate actuator is dead. Which brings me to my point. I removed the actuator and plugged the line on the turbo outlet. I drove the car today since my wife is driving my other car. It seems to run fine, if whimpy n/a power can be considered fine. Why don't you try the same thing? If your wastegate is too small then you'll get some boost. Just a thought. I'd still say your problem is in the actuator.
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PMan_S13
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Well driving it is not the problem.. besides the fact I really can't tune it yet so it is rich as a mutha and of course the elusive idle problem.. all I have to do is not get on it. But that really wasn't the point of the project =P
What's the best way to test my wastegate?
I've been spending my days off just slowly sorting out things that can not be the problem. Vacuum is good, flow to the wastegate seems to be good, lines hold pressure with no leaks, boost gauge is accurate.
What I want to look into now is the wastegate more thouroughly. First I want to see that the wastegate opens at the correct pressure. (I tested this months ago, but can't remember the best way to do it. I tried it again last night by t'ing my boost gauge off the same line as my wastegate and them plugging it into an air compressor. Took 22 psi to show movement. ? Now I'm confused ) If my wastegate is fine then it might be that I am not getting the right pressure from the signal line. I'll borrow my buddies boost gauge and plug it into the wastegate signal line. That way I can see pressure at the manifold (should be correct) and pressure in the signal. Now if I am getting signal and the wastegate is opening properly then it must be flow problems.
But for now what's the best way to test the wastegate?
What's the best way to test my wastegate?
I've been spending my days off just slowly sorting out things that can not be the problem. Vacuum is good, flow to the wastegate seems to be good, lines hold pressure with no leaks, boost gauge is accurate.
What I want to look into now is the wastegate more thouroughly. First I want to see that the wastegate opens at the correct pressure. (I tested this months ago, but can't remember the best way to do it. I tried it again last night by t'ing my boost gauge off the same line as my wastegate and them plugging it into an air compressor. Took 22 psi to show movement. ? Now I'm confused ) If my wastegate is fine then it might be that I am not getting the right pressure from the signal line. I'll borrow my buddies boost gauge and plug it into the wastegate signal line. That way I can see pressure at the manifold (should be correct) and pressure in the signal. Now if I am getting signal and the wastegate is opening properly then it must be flow problems.
But for now what's the best way to test the wastegate?
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WAbernethy
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I use my vaccum pump and t off my boost gauge to read the pressure. If it took 22 psi to move the actuator then the diaphram inside the actuator might have a small leak or something. Mine used to open at around 5 psi. Now it dosen't allow any pressure to build in the line and won't open at all. I could hear the air leaking from inside the actuator.
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PMan_S13
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Well if anyone is interested, I am about 99% sure I figured out what was wrong.
I tested and retested wastegate. It's definately not a 7 psi wastegate. It opens fully at about 15 psi so I'm guessing this is a 1 bar wastegate.
I wrote a very "nice" email to the guys I bought the turbo from.. should get a response tomorrow
I tested and retested wastegate. It's definately not a 7 psi wastegate. It opens fully at about 15 psi so I'm guessing this is a 1 bar wastegate.
I wrote a very "nice" email to the guys I bought the turbo from.. should get a response tomorrow
Hope they give you the correct spring or something.
One of my concerns when turboing was if they had given me the right spring with my 35mm Tial. Hell... they had already given me the wrong turbo, luckily I cross-checked the part #s with the turbonetics catalog and they gave me the correct one shortly after. But the wastegate, I had no way of knowing. Luckily for me they did give the right spring.
Hope it works out for ya
One of my concerns when turboing was if they had given me the right spring with my 35mm Tial. Hell... they had already given me the wrong turbo, luckily I cross-checked the part #s with the turbonetics catalog and they gave me the correct one shortly after. But the wastegate, I had no way of knowing. Luckily for me they did give the right spring.
Hope it works out for ya