softopz Posted September 15, 2009 Share Posted September 15, 2009 Hey guys, I just finished getting my car running and trying to break it in. | Its a stock l28et just rebuilt motor. stock everything pretty much . Iam using ms2 with EDIS ignition . My issue is I drove it the other day looking at the boost gauge and it climbed to 15 psi and heald steady. I dont have an IC or a BOV yet it was a bit scary cause I heard some pinging. I havent made any adjustments to the wastegate or diaphgram. Iam going to put the Pop off Valve in the meantime cause it started pinging and I dont want to take any chances. I also have a cheap ebay graigner type MBC could this resolve my issue? since I was going to eventually put it in anyway. Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted September 15, 2009 Share Posted September 15, 2009 What are you using for boost control right now? Is your wastegate connected properly? A MBC will only raise and not lower your boost. You need to get your wastegate working properly. The blow off valve won't do anything for this issue. Quote Link to comment Share on other sites More sharing options...
softopz Posted September 15, 2009 Author Share Posted September 15, 2009 I dont have a boost controller yet. I wasnt going to put the blow off valve to fix my problem. I was refering to the pop off valve on the intake that I plugged it vents at 10 psi. Just as a measure of protection, however it looks like I have to test my wastegate. Could be a bad one..I dont know though cause I never ran the car till now. Whats the best way to route the wastegate signal? Mine is a T 2 vaccum lines both to compressor side of turbo, the other end is to waste gate. Should change the source to intake manifold? Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted September 15, 2009 Share Posted September 15, 2009 I dont have a boost controller yet. I wasnt going to put the blow off valve to fix my problem. I was refering to the pop off valve on the intake that I plugged it vents at 10 psi. Just as a measure of protection, however it looks like I have to test my wastegate. Could be a bad one..I dont know though cause I never ran the car till now. Whats the best way to route the wastegate signal? Mine is a T 2 vaccum lines both to compressor side of turbo, the other end is to waste gate. Should change the source to intake manifold? Nah, that's perfectly fine. Quote Link to comment Share on other sites More sharing options...
softopz Posted September 15, 2009 Author Share Posted September 15, 2009 There has to be something I could do. I dont think this would be a boost spike cause it stays at 15 psi and the stock boost should be only 5-7 psi. There is something definatly wrong here. If I punch it and hold it at WOT it will hold 15 psi 10-15 depending how full a throttle Im pushing. Iam going hose to change the clamps and hoses on the wastegaste could be leaking. Any ideas guys should do lengthen the rod of the waste gate?! sorry I am new to this and trying to remember what I have read about wastegates/turbos Quote Link to comment Share on other sites More sharing options...
DeleriousZ Posted September 15, 2009 Share Posted September 15, 2009 Have you tested the wastegate for proper operation? It kind of sounds like it is sticking. Replacing the vacuum lines for the wastegate would be a good idea as you said. Quote Link to comment Share on other sites More sharing options...
ktm Posted September 15, 2009 Share Posted September 15, 2009 One possibility as to why it is holding at 15 psi is most likely due to wastegate creep by exhaust backpressure. My 15 psi wastegate would creep open and hold boost at 19/20 psi due to backpressure. I saw this occurring on a Mustang dyno while tuning and tested my theory by closing my boost contoller entirely which would allow it to overboost all it wanted. Sure enough, it would hit 19/20 psi and hold. Others see this at higher rpm and boost bleed off. Quote Link to comment Share on other sites More sharing options...
softopz Posted September 15, 2009 Author Share Posted September 15, 2009 Delerious do you know the procedure off hand to testing the wastegate. KTM thats pretty interesting but your referring to a 15 psi external wastegate correct. Quote Link to comment Share on other sites More sharing options...
ktm Posted September 16, 2009 Share Posted September 16, 2009 No, a 15 psi internal wastegate. Quote Link to comment Share on other sites More sharing options...
madmatt48 Posted September 16, 2009 Share Posted September 16, 2009 There has to be something I could do. I dont think this would be a boost spike cause it stays at 15 psi and the stock boost should be only 5-7 psi.There is something definatly wrong here. If I punch it and hold it at WOT it will hold 15 psi 10-15 depending how full a throttle Im pushing. Iam going hose to change the clamps and hoses on the wastegaste could be leaking. Any ideas guys should do lengthen the rod of the waste gate?! sorry I am new to this and trying to remember what I have read about wastegates/turbos From your description of the problem, it sounds to me that your internal wastegate could be stuck in the closed position which causes the turbine to put out its maximum pressure and spin to its maximum rpm limited to how much exhaust pressure is driving it. Normally the limit to the internal wastegate for boost pressure depends on the spring inside it, once the boost is high enough it compresses the spring inside the internal wastegate actuator and the arm actuates opening the turbine exhaust bypass valve releasing excess exhaust that is not needed to maintain the amount of boost that the spring inside the internal wastegate is rated at. One way to isolate the cause of the stuck internal wastegate is to disconnect the internal wastegate rod from the wastegate actuator and move the back and forth to verify the wastegate arm opens and closes the wastegate valve freely. If it is stuck and does not move back and forth (open and closed) It could be either stuck or seized due to something lodged in there, excessive rust or heat stress corrosion from sitting a long time (the valve is iron and so is the turbine housing so it could rust together) If that is the case and it is stuck, it may require that the downpipe be removed and the bolts holding the turbine discharge pipe to allow inspection of the rear part of the turbine and the small wastegate valve right next to it. You may get lucky enough to spray some break free or liquid wrench on the iron wastegate lever arm and wastegate valve assembly(let it soak a while) to get it to actuate freely again, if not, replace the wastegate valve assembly. It is bolted to the end of the turbine itself by I believe 5 or six bolts. If the wastegate arm moves freely open and closed/back and forth: Another problem is that the wastegate actuator boost pressure line is blocked or not connected to an adequate boost source to allow the actuator to open and move the rod open or closed. Or the internal wastegate arm actuator has an internal leak and even if boost pressure enters it, it leaks before it builds enough pressure to compress the spring to move the wastegate actuating lever arm. If that is the case, it needs to be replaced with a new one. HKS and some other manufacturers make great replacement internal wastegate actuators if that is indeed the problem. Hope this helps isolate the excessive boost out of control problem. Quote Link to comment Share on other sites More sharing options...
softopz Posted September 16, 2009 Author Share Posted September 16, 2009 THANKS ALLOT that was really informative I am going to just that in the next couple of days. I will so try to find a regulator for an air compressor and bench test the wastegate to see when and when its opening and closing. I ll keep you guys posted. Quote Link to comment Share on other sites More sharing options...
DeleriousZ Posted September 16, 2009 Share Posted September 16, 2009 Delerious do you know the procedure off hand to testing the wastegate. KTM thats pretty interesting but your referring to a 15 psi external wastegate correct. grab the rod and see if you can open the flapper by hand. if you can and the operation is smooth then it's not sticky. Quote Link to comment Share on other sites More sharing options...
softopz Posted September 16, 2009 Author Share Posted September 16, 2009 with the rod connected to the flapper try to move it? Quote Link to comment Share on other sites More sharing options...
HowlerMonkey Posted September 19, 2009 Share Posted September 19, 2009 The spring is pretty damn strong so it will be hard to move. I would undo the hose, the two bolts that hold it on, and the pin that holds the actuator arm to the lever and take out the actuator........or you can use one of the pressure/vacuum pumps and see if it moves when you apply pressure to the actuator port. Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted September 20, 2009 Share Posted September 20, 2009 with the rod connected to the flapper try to move it? The flapper just sits there; it doesn't take any force to move it. The spring is strong but it can be done; you just have to get a good grip on it. The spring rate of the actuator affects it a lot. If it was the stock Holset wastegate actuator, then you probably would not be able to move it. Quote Link to comment Share on other sites More sharing options...
softopz Posted September 24, 2009 Author Share Posted September 24, 2009 A litte update, I removed the actuator rod and moved the flapper at the turbo i was getting about 30 degree movement.I noticed when I attached the wastegate rod back on I got only about 20 that last 10 degree was the issue thats when I put the aircompressor and blew into wastegate hose. Nothing was stuck turned out the wastegate assembly was bent towards the front of the car. I bent it back to the rear closer to flapper blew some air back and saw the whole flapper engage and disengage. Took the car out for a run beauttttty holds tight at 5-7 psi ! Now to install the Manual boost control and turn it to 9 psi Iam reading up and some people have mixed opnions for the boost source. Some say Its best to take it from intake manifold and some say the best is at the turbo. What should I do? and which fitting of the MBC goes where? Quote Link to comment Share on other sites More sharing options...
DeleriousZ Posted September 24, 2009 Share Posted September 24, 2009 Routing it off of the compressor will give you the best anti-boost-spike control, routing it off of the intake manifold will give you the most accurate control, especially if your boost gauge is pulled from the same source. Quote Link to comment Share on other sites More sharing options...
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