LQ9 6.0L PT88 w/ Truck Manifolds in an FBody Build w/ Pics
07-25-2009, 10:01 AM
#303
Getting a little frustrated. Still haven't figured out where my boost went.
About 2 weeks ago I finally got around to pressurizing the cold side and try to hunt down my boost leak. Everything seemd tight. The only air that I was able to find escaping was around the injector orings. I found that the bolts that hold down the fuel rails were a little loose. Tightened it all up, took it for a blast and same ****. down 2 lbs on the spring and about 4-5 lbs on the manual controller.
To be clear, boost isn't falling off. Everything seems fine and behaving exactly the same as before. I am just not getting to the same boost levels with the same setup.
I decided to pop off the wastegate and inspect it. I found that the diaphragm had a small tear in it. The diaphragm that these cheap X02 Wastegates use is cheap garbage. I found out that you can use the much better diaphragm from a TiAL instead so I ordered one and put it in. Same ****. And now I think I have a vacuum leak because the car is idling about 100-150 rpm higher. I'm getting frustrated.
07-25-2009, 01:22 PM
#306
07-25-2009, 05:38 PM
#308
I know they should be changed but why would this symptom have anything to do with valve springs. I'm defintly not floating valves. It runs perfect. It's just making less boost on the mechanical gage and the MAP sensor.
Single 4" flows well. It was not easy getting it out of the engine compartment.
I used my lincoln mig for the first time last weekend, and after about 30 minutes of welding I feel pretty confident in my ability to make an exhaust system. So, I guess I'm one step closer to building my own, lol. I might try a few simple exhaust mods to my car right now before I try building a turbo kit from scratch. Since I'd like to run a 4" down pipe to the rear in the future, I don't see the harm (or waste) in removing the 3" catback completely and running a 4" pipe over the axle (from my current 4" Y pipe) to a 4" muffler, like a magnaflow. Trying to fab up a 4" pipe to run over the axle out of premade mandrel bends is going to be pretty tricky in itself. Id say it would make for great practice for working in tight areas... plus I could use it later in my turbo build, so its not wasted work. And I supose it would improve the "right now" flow and sound
07-25-2009, 11:20 PM
#310
You used the BMR Turbo K member, right? I plan on going with one of those so I might have a little better luck getting that thing out of the engine compartment and hooked into a 4" exhaust routed to the rear. I bet it would be hell to get a 4" pipe out without cutting a hole in the fender or bumper, lol.
07-26-2009, 09:10 AM
#314
Since the mechanical boost gage is reading the same as the 2 bar MAP sensor and one reads it from the front of the intake and the other from the back, I'd say that I am really down on boost. My butt meter agrees as well.
But that would mean that they were floating and they aren't.
But that would mean that they were floating and they aren't.
07-26-2009, 12:34 PM
#315
Whats the KPA, before the loss of boost and after? What is ambient temp compared to those 2 as well? As it gets hotter, it will be lazy, when it cools down and becomes turbo weather, you will find out its just strait nasty in cold weather.
How are your gaskets leading into the turbo? Loss of back pressure will hurt it too, even though the gate should absorb it, thats not always the case.
How are your gaskets leading into the turbo? Loss of back pressure will hurt it too, even though the gate should absorb it, thats not always the case.
07-26-2009, 02:35 PM
#316
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Do you have a boost controller? Anyone you know have a gate you're sure is working properly that you can throw on your car real quick (could be a weak spring or something else internal in the gate)? Also might want to fix the vaccuum leak and see if that doesn't fix your boost issue.
07-26-2009, 06:00 PM
#317
Whats the KPA, before the loss of boost and after? What is ambient temp compared to those 2 as well? As it gets hotter, it will be lazy, when it cools down and becomes turbo weather, you will find out its just strait nasty in cold weather.
How are your gaskets leading into the turbo? Loss of back pressure will hurt it too, even though the gate should absorb it, thats not always the case.
How are your gaskets leading into the turbo? Loss of back pressure will hurt it too, even though the gate should absorb it, thats not always the case.
My biggest frustration is that I dont have enough experience with turbos in order to know the symptoms of a cold side leak/problem vs a hot side leak/problem. How can you tell if the BOV is maintaining a lower boost level vs the wastegate?
Here's the entire story leading up to this problem. I took the car to the track. I made a 10.teen pass at almost 135 MPH which was good considering the weather being really hot. 2nd pass sometime just before the 1/8 mile I felt the boost drop off about 3-4 lbs and continued the pass with a 10.5x. Then the rain came. I took out the torque converter and sent it out to get tightened up 1K RPM (it was loose still from my previous setup). I put the car back together and I have been missing the boost since.
I pressurized the cold side and found that I was leaking around the injector orings. Tightened the fuel rails down and fixed that but apparently that wasn't the problem. Took out the wastegate and found a pinhole in the diaphragm. Replaced it and same problem. I'm pretty sure that NOW I have a vacum leak since it's idling a little higher than normal. Haven't felt like looking at it in a couple days.
07-27-2009, 11:43 AM
#319
An damage to either hot or cold side blades? broken/missing?
Any oil leaks? Like under the valley cover? waste gate line torn or kinked? Booster line to the manifold issue? Fittings to the manifold? Your running the fiber tuned right? Any hairline cracks anywhere? Sorry if these sound like stupid questions, I know your a smart dude,..just asking normal checklist questions.
Any oil leaks? Like under the valley cover? waste gate line torn or kinked? Booster line to the manifold issue? Fittings to the manifold? Your running the fiber tuned right? Any hairline cracks anywhere? Sorry if these sound like stupid questions, I know your a smart dude,..just asking normal checklist questions.
07-28-2009, 01:04 PM
#320
I checked all that last time around when I found the tear in the diaphragm and the leak around the injectors. I need to do it again as soon as my buddies garage becomes available again. With all the rain that we've been getting, working on my car outside with all the mosquitos is not an option out here in the swamp.