New turbo, no power

[Laine D]

I spent almost the entire day fighting with this thing again. I got the timing meter Thursday and got timing dialed in about 8 degrees. I also took the slip pipe apart and packed it full of copper RTV a couple days ago. No exhaust leaks now, but it would still top out at only 6 psi when I test drove it. I switched back to the original wastegate and no change. Finally out of frustration I wired the wastegate shut and saw the boost jump up a little over 15 before I let off. So, I went back and changed springs in the wastegate. I changed springs twice and finally hit 14 psi. I'm currently using the heaviest spring in the kit which is 2.0 bar (29 psi). I have the rod turned in 5 turns past where it will slip over end of the wastegate, which according to the chart that came with the actuator should set opening pressure at 18.5. I'm going to put my hand pump on tomorrow and see how much pressure it actually takes before it starts opening before I make any more changes.

I'm still only seeing about 1 psi while cruising. Is that normal? Moderate acceleration brings it up to 6-7 and wide open pulling a long hill it tops out at 14. EGTs are still running a little high during a hard pull, around 1100 and creeping toward 1200 before I let off.

I am not Intercooled so my numbers are probably higher. What are your Rpms at cruising? At 55 I’m around 2000 and 3 psi of boost. It I foot it I can easily hit 10 psi, but my waistgate won’t hold any more than 10. I believe the factory springs on these turbos get worn out over time and it’s possible that the aftermarket one you have just needs a tighter spring.

 

[cozinsky]

I have 3.55 gears and a ZF. I think I'm running around 1800 at 55. I have the stiffest spring in it now. I'm going to have to put my hand pump on and find out exactly what pressure it's starting to open at. The only adjustment left is tightening up the preload more.

 

[tjsea]

So it sounds like it is running better and that you just need to get the wastegate dialed in yet, am I correct? Did getting the timing dialed in correctly help with power and spool up?

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[cozinsky]

I can't say the timing made any noticeable difference because the wastegate was preventing it from building any boost. Once I figured that out it helped a lot, but I'm still not sure what is actually normal. It seems strange even with the heaviest spring it still won't go over 15. It's tight, I couldn't even pull the actuator out by hand to connect it. I had to put air pressure on it to extend it slightly.

 

[cozinsky]

I'm referencing the wastegate directly off the hot side of the turbo too. There is no boss for a nipple on the turbine housing and the housing is too thin to drill and tap, so I made a nipple by drilling a 1/8 hole straight through a 5/16 bolt, drilled a hole through the hose directly off the turbo and put a washer with o ring on each side of the hose and tightened it down.

 

[tjsea]

So if I'm reading this right, you drilled and tapped the turbine housing for the wastegate? The wastegate should reference off of the boost pressure, not the drive pressure. Drive pressure is always higher than boost. There is usually a port on the compressor housing, or it can be pulled from a boost pressure gauge port.

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[cozinsky]

Here's a picture of what I did. There is no port on the housing and it's too thin to drill and tap, so I took a 5/16 bolt and drilled a 1/8 hole all the way through it. I drilled a hole in the hose directly in front of the compressor housing, put a washer with o ring on each side, pushed the bolt through the hose, tightened the nut and slipped the hose over the end of it.

I searched all over online on where to reference the wastegate on an intercooled system, pre or post intercooler and found people doing it both ways, but seemed like most said to put it as close as possible to the compressor housing.

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[Laine D]

Here's a picture of what I did. There is no port on the housing and it's too thin to drill and tap, so I took a 5/16 bolt and drilled a 1/8 hole all the way through it. I drilled a hole in the hose directly in front of the compressor housing, put a washer with o ring on each side, pushed the bolt through the hose, tightened the nut and slipped the hose over the end of it.

I searched all over online on where to reference the wastegate on an intercooled system, pre or post intercooler and found people doing it both ways, but seemed like most said to put it as close as possible to the compressor housing.

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Have you tried to put some vice grips on the tube for the waistgate? So that it’s not getting any boost reference at all? If not I’d try that. I don’t think that many people with higher power rigs even run the boost reference. It could definitely be helping the waistgate open. The exhaust pressure itself will open the waistgate without any force from the boost reference line. I’d try that.

 

[cozinsky]

Tonight I put my hand pump on the wastegate actuator. It took 28 psi before the actuator even started to move, so it has to be exhaust pressure forcing the wastegate open, not boost pressure. I put two more turns of preload on the actuator which raised the opening pressure to 30 psi with my pump. Took it out on another test drive and it still tops out at 14 psi boost. Aside from locking the wastegate shut I guess that's all it's got. Is it normal to have that much exhaust pressure forcing the wastegate open? I haven't tried pinching off the reference line yet, didn't have a vise grips with me so without the assist of boost pressure it might help. I'm going to run it this way and see how it works. I don't know if I even need more boost than that. I left the wastegate connected so I'd have a safety net since I'm running stock valve springs.

 

[Laine D]

Tonight I put my hand pump on the wastegate actuator. It took 28 psi before the actuator even started to move, so it has to be exhaust pressure forcing the wastegate open, not boost pressure. I put two more turns of preload on the actuator which raised the opening pressure to 30 psi with my pump. Took it out on another test drive and it still tops out at 14 psi boost. Aside from locking the wastegate shut I guess that's all it's got. Is it normal to have that much exhaust pressure forcing the wastegate open? I haven't tried pinching off the reference line yet, didn't have a vise grips with me so without the assist of boost pressure it might help. I'm going to run it this way and see how it works. I don't know if I even need more boost than that. I left the wastegate connected so I'd have a safety net since I'm running stock valve springs.

Seeing as that’s Damn there the exact number I top out on, I believe that’s the issue. I believe that’s the whole reason wes started making the waistgate blockoffs.

 

[John Scott]

I just install a new pump and timed it using the rotunda luminous method.... timing should be at 2.5 this way.... first u will static time the pump lines match... for every 1/8 in to pass side is equivalent to 4 degrees... mine is not quite 1/4 in passenger side.... then I hooked up a farral meter and timing light to see what it was set at and its at 8.5 degrees btdc at 2000 rpm....

 

[John Scott]

So, how do I set ATDC? I know where the zero mark is on the timing tab, but all I can do is dial in degrees of advance on my timing light, no negative adjustment. How do I read this correctly?

U have to set your meter at -21 degrees before u start the motor then at 2000 rpm u set the ip timing to 2.5 positive degrees.... that will equate to 8.5 degrees btdc

 

[The_Josh_Bear]

Tonight I put my hand pump on the wastegate actuator. It took 28 psi before the actuator even started to move, so it has to be exhaust pressure forcing the wastegate open, not boost pressure. I put two more turns of preload on the actuator which raised the opening pressure to 30 psi with my pump. Took it out on another test drive and it still tops out at 14 psi boost. Aside from locking the wastegate shut I guess that's all it's got. Is it normal to have that much exhaust pressure forcing the wastegate open? I haven't tried pinching off the reference line yet, didn't have a vise grips with me so without the assist of boost pressure it might help. I'm going to run it this way and see how it works. I don't know if I even need more boost than that. I left the wastegate connected so I'd have a safety net since I'm running stock valve springs.

I run my wastegate unplugged and just put a bolt in the reference tube so I don't lose boost. My gate begins to open around 10 or 11 psi and I can get up to 14psi unloaded depending on circumstance. Engine/turbo stuff in my siggy.
With your really nice turbo it flows a ton and so at cruise I would expect lower boost numbers. I rarely get to drive 55 on my daily stuff but when I do it's probably around 2-3psi. I am usually up at 75mph cruising and on flat ground 4ish psi. But it's hilly around here so I don't get to see "flat ground" a ton haha.
So yes it's normal for the wastegate to blow open, but remember since you still have your reference line on and then the drive pressure also acting on the waste gate it's not surprising that 14 is where it opens. Put a bolt on the reference tube and you might be surprised at the results.