Boost lower than usual
03-06-2006, 01:28 AM
#1
Boost lower than usual What the heck happened? Now only get 4 psi boost, instead of the usual ol 7. It was fine before it got hit, and now this. I fixed one of the couplers going to the intercooler today, it was crunched down from the wreck (pushed the charge pipe in). Tried it without the air filter to see if it had to do with it being clogged, same thing. I have a 7# spring in the progate and my boost controller screwed all the way in. This is really really irritating. How do you guys "pressure test" the charge pipe?
03-06-2006, 08:24 AM
#2
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Whoa... should the boost controller be screwed all the way in? I've screwed mine all the way in and I get, like, 2 psi. It should be loosened to run the full psi specs on the wastegate, no?
03-06-2006, 11:54 AM
#4
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Sounds like you need to loosen it... but not all the way!!! First tighten it, and start loosening it little by little until you achieve the desired boost... up the max determined by Wastegate/BOV, of course.
Unless, there is another problem.
Unless, there is another problem.
03-06-2006, 02:04 PM
#5
I'm confused... don't BC's allow you to go above the rated (WG spring) boost, not below. This has been a HUGE controversy and no one can give me a straight answer. If I screw it all the way in (which it is), shouldn't it be at 7#? If I unscrew it, it should go higher than 7. Tell me if I'm wrong...
03-06-2006, 02:18 PM
#6
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try unhooking your boost controller like it was never there and try that, if you have a 7# spring in your wastegate then obviously you should be at 7#s, could be your wastegate, might have a clog or debris in it , might want to take it off and clean it out,if all that checks out, un hook your intake piping from the maf, and back by the turbo and blow some compressed air through it, maybe something is clogged or flapping in your piping, good luck.
03-06-2006, 02:29 PM
#7
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Good idea.
Isn't that a pretty big WG for running only 7 psi? I'm surprised it's not only NOT creeping past, but not even reaching it (7#)
. Myabe I'm wrong.
The boost controller can only regulate boost BELOW what your wastegate is allowing, not above it. For example: You could have a 13 lb spring and use the boost controller to set it at 8 psi for the street and then open it for the track. Someone, please correct me if I'm wrong...
Isn't that a pretty big WG for running only 7 psi? I'm surprised it's not only NOT creeping past, but not even reaching it (7#)
. Myabe I'm wrong.The boost controller can only regulate boost BELOW what your wastegate is allowing, not above it. For example: You could have a 13 lb spring and use the boost controller to set it at 8 psi for the street and then open it for the track. Someone, please correct me if I'm wrong...
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03-06-2006, 02:37 PM
#8
That's so weird. I have a turboxs standard boost controller, and a turbosmart progate 48mm. With that big of a wastegate, it should be able to support that low of boost. You need a bigger wastegate for lower boost because it has to bypass so much more before it hits the turbo. Everywhere I've read about the manual wastegate design (turboxs), allows you to increase boost 0-12psi. Kind of strange. I'll take your advice and pull it apart, double check, and then go from there.
03-07-2006, 12:59 AM
#9
Well I put a .040" restrictor flange on the inlet to the turbo and tightened all the bolts. Double checked all couplers and vacuum lines. Unscrewed the boost controller 3 turns, and tried it. Unscrewed another full turn, and still saw about 5psi. I took the wastegate off and pushed the valve in, it feels like it did when I first installed it and looks okay, no debris that I can see. I'm getting my boost reference from the front right before the MAF (which goes right into the TB like it was stock) so it's not pressure drop from the charge pipe and/or intercooler. It seems to spool up like normal just not boost up to 7. Perhaps I have a crack or something in the intercooler form the wreck? What do you guys think, time to somehow pressure test it? Just not exactly sure on how to go about doing that. Thanks for the help so far!
Maybe I'll keep loosening the boost controller to see what happens. It was getting dark and I don't have the light in my BC hooked up. I'll have to get my wastegate paperwork from my parents or look on the net, I think I'm gonna try just running the wastegate alone and see what happens like you suggested, just wanna make sure I don't hook it up wrong!
Maybe I'll keep loosening the boost controller to see what happens. It was getting dark and I don't have the light in my BC hooked up. I'll have to get my wastegate paperwork from my parents or look on the net, I think I'm gonna try just running the wastegate alone and see what happens like you suggested, just wanna make sure I don't hook it up wrong!
03-07-2006, 05:29 AM
#10
cap all lines hooked up to the charge piping, and take the piping off right at the turbo and off at the throttle body, use 2 pvc plugs from ace hardware 2.5" or whatever and 4" to plug those, thread a small port to hook up your boost gauge on the tb side and thread in any type of air hose fitting on the other end, fill up w/air to like 10lbs and see if it stays there or drops suddenly, listen for where the air is leaking from and or pour some water in a small spot if you cant quite pin point it... could be the ic but that would suck, might just be another coupler torn or partway ripped off....
03-07-2006, 12:46 PM
#12
bboyferal - yeah =(
I only have a total of 5 couplers, a 90 from the turbo to the charge pipe, then one more 90from the charge pipe to the intercooler, then another 90 to the upper pipe that has the BOV and goes to the MAF (where there is another one), then another between the MAF and TB. I have physically taken off the one on the charge to the intercooler (in) and inspected, as well as the turbo to charge, both are perfect. I adjusted the boost controller out 5 turns and still around 4 psi. That's a great idea with the PVC plugs, I'm gonna do that when I get the car back from the body shop (took it back to have them fix everything they f'd up or didn't finish the 1st time). I'm going to have the top end cleaned with BG products at a local turbo shop. Could a crack in my Y pipe cause the lag/low boost? I did have a pretty good sized crack in it a while back when I had the bullet put on before the turbo and it had to be welded back up. Just trying to figure out what the deal is!!! Really appreciate your advice/comments!
Tony
I only have a total of 5 couplers, a 90 from the turbo to the charge pipe, then one more 90from the charge pipe to the intercooler, then another 90 to the upper pipe that has the BOV and goes to the MAF (where there is another one), then another between the MAF and TB. I have physically taken off the one on the charge to the intercooler (in) and inspected, as well as the turbo to charge, both are perfect. I adjusted the boost controller out 5 turns and still around 4 psi. That's a great idea with the PVC plugs, I'm gonna do that when I get the car back from the body shop (took it back to have them fix everything they f'd up or didn't finish the 1st time). I'm going to have the top end cleaned with BG products at a local turbo shop. Could a crack in my Y pipe cause the lag/low boost? I did have a pretty good sized crack in it a while back when I had the bullet put on before the turbo and it had to be welded back up. Just trying to figure out what the deal is!!! Really appreciate your advice/comments!
Tony
03-08-2006, 12:53 PM
#13
Well, I must have a leak or something... A friend suggested I disconnect the WG so it'd build unlimited boost (and control it with the pedal of course), and I got the same amount of boost with it disconnected. With my setup and the T70 in a rear mount with 3" single going into the turbo, where do you all think I should see full boost? Again, this is a 6 speed car with 4.10's on a 255/50/16 tire, so assume it's under load (3rd or 4th gear). Guess I'll be pressure testing the charge system. I sure hope it's not a cracked intercooler!
03-08-2006, 01:25 PM
#14
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Originally Posted by bboyferal
Good idea.
The boost controller can only regulate boost BELOW what your wastegate is allowing, not above it. For example: You could have a 13 lb spring and use the boost controller to set it at 8 psi for the street and then open it for the track. Someone, please correct me if I'm wrong...
The boost controller can only regulate boost BELOW what your wastegate is allowing, not above it. For example: You could have a 13 lb spring and use the boost controller to set it at 8 psi for the street and then open it for the track. Someone, please correct me if I'm wrong...
It sounds like you have a leak or blockage on the intake/cold side of your system. You could check it using a few parts from the plumbing department at home depo and an air compressor. Use a rubber pipe plug one side (looks like a rubber football with a schrader valve on it) and a PVC cap with a compressor hose fitting threaded into it, on the other. hook your compressor hose to the hose fitting, turn your comressor on at 10-20psi and listen for leaks.
03-08-2006, 01:30 PM
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Here's a link to what I'm saying to test the system.
http://www.volvoclub.org.uk/faq/Spec...PressureTester
http://www.volvoclub.org.uk/faq/Spec...PressureTester
03-08-2006, 07:32 PM
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Originally Posted by SUPER DAVES Z
Sorry buddy, you got it backwards. The BC will not let you go below the spring rating. so if you have a 7lb spring, it "should" go no lower than 7psi. The boost controller would then allow you to boost above that to say 13psi or whatever.
It sounds like you have a leak or blockage on the intake/cold side of your system. You could check it using a few parts from the plumbing department at home depo and an air compressor. Use a rubber pipe plug one side (looks like a rubber football with a schrader valve on it) and a PVC cap with a compressor hose fitting threaded into it, on the other. hook your compressor hose to the hose fitting, turn your comressor on at 10-20psi and listen for leaks.
It sounds like you have a leak or blockage on the intake/cold side of your system. You could check it using a few parts from the plumbing department at home depo and an air compressor. Use a rubber pipe plug one side (looks like a rubber football with a schrader valve on it) and a PVC cap with a compressor hose fitting threaded into it, on the other. hook your compressor hose to the hose fitting, turn your comressor on at 10-20psi and listen for leaks.
Hmmm... So if I run a 7 lb. spring by itself, I would max the boost at seven lbs.
But if I add a boost controller, it will allow the boost to peak higher? I guess I have it backwards??? How have I tightened it and reduced my boost?
03-10-2006, 12:56 AM
#19
I got all of the components needed to pressure test the system at Home Depot. I did not detect any leaks in the system. A buddy of mine came over and we played around with it, and got no where. We went for a ride, and it only makes 1-3psi in 1st-4th and finally got to 4.5-5 in 5th. I know I have an exhaust leak on the passenger side collector, but would this cause this kind of problem? I am so irritated with this system, I could use all the help I can get!
03-10-2006, 09:09 AM
#20
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Originally Posted by 67Firebird455
I got all of the components needed to pressure test the system at Home Depot. I did not detect any leaks in the system. A buddy of mine came over and we played around with it, and got no where. We went for a ride, and it only makes 1-3psi in 1st-4th and finally got to 4.5-5 in 5th. I know I have an exhaust leak on the passenger side collector, but would this cause this kind of problem? I am so irritated with this system, I could use all the help I can get!
A small exhaust leak should not lower boost that much, although it will obviously hurt the efficiency of the system.
Later,
Dave