Boost Help?
If you follow the hose from the boost gauge one end will be connected to the back of the gauge and the other(the source) will be "T"ed into a line connecting into the fuel pressure regulator line.
The boost gauge is not likely to be your problem though. Neither is the MBC, or the diverter valve likely to be the source of your troubles.
Most likely your problem is related to WG spring pressure being set at 11 PSI. However, not to fret as the waste gate spring pressure is adjustable.
The boost gauge is not likely to be your problem though. Neither is the MBC, or the diverter valve likely to be the source of your troubles.
Most likely your problem is related to WG spring pressure being set at 11 PSI. However, not to fret as the waste gate spring pressure is adjustable.
No need to remove the WG. No need to purchase a new WG either. The wastegate is adjustable. Someone posted up a how-to video for you. I suggest that you read it. If you can't open that link then there is an instructional on the Forced Performance website I think.
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Joined: Aug 2008
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From: riverside, ca
no you guys got it all wrong, op heres your issue if your adjusting your boost controller knob, and its staying on the boost gauge around 10-11 psi, sounds like previous owner, hooked up one line off the compressor nipple directly to the wastegate. Look underhood, underneath where your intake pipe connects to the cold side of the turbo, youll see two areas where there are vacuum lines, one connects to a nipple coming off the housing, other sits on the wastegate. The line coming off the nipple needs to go to the in end on the boost controller. The out end needs to connect to the wastegate. Refer to your hallman mbc manual, as to which fittings on the mbc goes to which end of the turbo. Guys personally I dont think him preloading the wastegate is going to do anything. Its an issue with his boost controller. Good luck.
I was just suggesting it as a 10 min trouble shooting step, to to OP you can do it without removing the turbo pop the hood and look down. Kinda hard to determine the issue without the car physically there and having a guy that is not very mechanicly inclined describing the symptoms.
Yeah he should make sure that the MBC is hooked up correctly. If you follow the two hoses that are connected to the MBC, where does the other end of each hose connect to OP?
If we consider the MBC's adjustment knob as being located on the topside of the MBC then the nipple(port) on the "bottom", or opposite end from that knob is called the reference port. This reference port should be connected via a hose to the reference source which is usually the nipple on the turbo's compressor housing discharge tube(although some peeps "T' into the hose that runs from the intake manifold to the diverter valve).
The other nipple on your MBC we'll refer to as the control port. It is located on the side of the MBC at right angles to both the adjustment knob and the reference port. This control port should be connected via a hose directly to the nipple(port) located on the waste gate actuator.
If we consider the MBC's adjustment knob as being located on the topside of the MBC then the nipple(port) on the "bottom", or opposite end from that knob is called the reference port. This reference port should be connected via a hose to the reference source which is usually the nipple on the turbo's compressor housing discharge tube(although some peeps "T' into the hose that runs from the intake manifold to the diverter valve).
The other nipple on your MBC we'll refer to as the control port. It is located on the side of the MBC at right angles to both the adjustment knob and the reference port. This control port should be connected via a hose directly to the nipple(port) located on the waste gate actuator.
Last edited by sparky; Jan 11, 2012 at 08:56 AM.
The reason that I recommended first setting the wastegate preload with the boost reference source connected directly to the WGA's signal port is that it tends to definitively eliminate, and/or identify the MBC as a possible cause of the low boost problem.
Helping to narrow down the possible causes of this low boost scenario is what we are doing anyway, isn't it? Also, let's assume that as you suggest, the MBC's lines are indeed hooked up incorrectly. The fact remains that his wastegate spring pressure is set at its lowest possible level(base pressure= 11 PSI). So, it should be increased anyway at least up to 14 PSI, or he'll continue to have dog awful turbo spool up.
EDIT: FWIW, I have found that you'll get the very best turbo spool response and boost control out the top, from your MBC if you limit the operating range of the MBC(that is the range between the preloaded set point at the bottom of the range and your peak boost level. By contrast when your MBC has a relatively light internal spring rate and it has to control a wider operating range, let's say from 11 PSI up to 25 PSI, then spool up and ultimate control at the top of the range are adversely impacted.
Don't get me wrong, dastallion, I am not arguing with you. In fact, I agree with you that the OP should also verify correct MBC boost hose routing. I just thought that it might be better if he disconnected his present hose assembly and threw it in the trash. Then set WG preload and finally reinstall new hoses routed correctly as you have suggested. But, that is just the sequence of steps that I would personally follow in attempting to solve a low boost issue. Nothing wrong with your approach though. He could also first connect his MBC properly and then set WG preload.
Helping to narrow down the possible causes of this low boost scenario is what we are doing anyway, isn't it? Also, let's assume that as you suggest, the MBC's lines are indeed hooked up incorrectly. The fact remains that his wastegate spring pressure is set at its lowest possible level(base pressure= 11 PSI). So, it should be increased anyway at least up to 14 PSI, or he'll continue to have dog awful turbo spool up.
EDIT: FWIW, I have found that you'll get the very best turbo spool response and boost control out the top, from your MBC if you limit the operating range of the MBC(that is the range between the preloaded set point at the bottom of the range and your peak boost level. By contrast when your MBC has a relatively light internal spring rate and it has to control a wider operating range, let's say from 11 PSI up to 25 PSI, then spool up and ultimate control at the top of the range are adversely impacted.
Don't get me wrong, dastallion, I am not arguing with you. In fact, I agree with you that the OP should also verify correct MBC boost hose routing. I just thought that it might be better if he disconnected his present hose assembly and threw it in the trash. Then set WG preload and finally reinstall new hoses routed correctly as you have suggested. But, that is just the sequence of steps that I would personally follow in attempting to solve a low boost issue. Nothing wrong with your approach though. He could also first connect his MBC properly and then set WG preload.
Last edited by sparky; Jan 11, 2012 at 09:10 AM.
no you guys got it all wrong, op heres your issue if your adjusting your boost controller knob, and its staying on the boost gauge around 10-11 psi, sounds like previous owner, hooked up one line off the compressor nipple directly to the wastegate. Look underhood, underneath where your intake pipe connects to the cold side of the turbo, youll see two areas where there are vacuum lines, one connects to a nipple coming off the housing, other sits on the wastegate. The line coming off the nipple needs to go to the in end on the boost controller. The out end needs to connect to the wastegate. Refer to your hallman mbc manual, as to which fittings on the mbc goes to which end of the turbo. Guys personally I dont think him preloading the wastegate is going to do anything. Its an issue with his boost controller. Good luck.
Accually you are right there was only one line going to the waste gate from the mbc and the other hose was merged 3 way in the BOV line, which i disconnected it and i put the other line down by the wastegate now too but the problem is still there.