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Old 11-28-2009, 12:46 AM   #226
LittleBlueGT
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I am now abandoning the hybrid boost control.

Why:

I get extreme temp fluxes, and in only 40 degrees spread (F) I am seeing a 1.5 psi difference. If that holds true, I will be hitting anywhere from 19 psi at 100F and 24.25 psi at -40F!

Maybe it works well for you guys that don't have big temp swings, but not for me.

Anybody else notice this?
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Old 11-28-2009, 08:28 AM   #227
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you need a better MBC if that's the case.
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Old 11-28-2009, 11:18 AM   #228
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Quote:
Originally Posted by ride5000 View Post
you need a better MBC if that's the case.
What temps have logged in?

Most of the MBCs really do look the same in terms of construction, I am not sure what the differences would be.

I have a new Perrin one BTW.
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Old 11-28-2009, 11:43 AM   #229
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I know my MBC is not working properly for me. My Tial EWG leaks a small amount of air (this is normal I hear) through the bottom port, anything that restricts airflow makes the boost rise. That likely explains why the MBC on its lowest setting raised boost from 14.5 to 17.5 psi.
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Old 11-28-2009, 12:30 PM   #230
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Quote:
Originally Posted by ride5000 View Post
you need a better MBC if that's the case.
How much variation with temperature do you see with your Hallman?
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Old 11-28-2009, 05:34 PM   #231
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Our hallman has been pretty steady from 45-90 degrees F. Maybe 0.2 psi difference.
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Old 11-28-2009, 07:23 PM   #232
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I've got an update for you guys on the plugging of the bleed port of the GM BCS. While it is true that we were loosing air through the other port of the BCS when the MBC opened, it actually had an advantage: In the past I also plugged the bleed hole of the MBC, worrying about airflow being lost, as you guys may know, this hole is to bleed some pressure to the atmosphere so that the pressure that is holding open the wastegate can be released when you let off the gas if you were just using an MBC for boost control. So now that all the bleed ports have been blocked off from that system, the wastegate isn't opening until the MBC opens, which is good, except: when the wastegate opens, it opens ALL the way right away.The boost builds up to 20 psi rapidly and then the MBC opens and the boost drops down to about 15 psi, and now that all the bleed ports have been sealed off, the wastegate stays open because the pressure is trapped in there. The boost will then slowly build back up to ~ 20 psi. So to solve this problem I believe the best approach would be to run a bleed port that has a restrictor pill in it, or just ditch the MBC, but since I have an EWG setup coming I'm just going to pull the MBC off and run the 3 port system alone until then.

All of this messing around with the factory boost control system makes me wonder, why doesn't anyone make an aftermarket wastegate actuator for the VF series turbo's'? If someone did, they should make it easy to swap out springs, or at least have some sort of spring preload adjustment built into it.

Last edited by 02RexWI; 11-28-2009 at 07:33 PM.
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Old 11-28-2009, 07:52 PM   #233
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^Nevermind, I guess they do sell aftermarket wastegate actuators for the VF series turbo's... That's probably the way i'd go, unless you are concerned with with running that much boost daily...
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Old 11-28-2009, 08:55 PM   #234
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Quote:
Originally Posted by LittleBlueGT View Post
I know my MBC is not working properly for me. My Tial EWG leaks a small amount of air (this is normal I hear) through the bottom port, anything that restricts airflow makes the boost rise. That likely explains why the MBC on its lowest setting raised boost from 14.5 to 17.5 psi.
Hey LB, Franz and I are using the Hallman with the cockpit adjuster cable/knob. It doesn't fluctuate very much with temps, maybe a bit higher when it's cold, but with the knob being adjustable from the driver seat it's a non-issue for us. If you'd like to try one PM me.

Last edited by adeliciouspizza; 11-28-2009 at 09:14 PM.
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Old 11-28-2009, 09:18 PM   #235
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Yeah I have the hallman with the cockpit adjust cable , I never see big swings in boost, When it was droping down to 35 degrees (and I tuned in 75 80 degrees) I wasn't even seeing .5 psi higher... I think it was about .3 psi... Now my txs dual stage bcs did some wacky **** when I tried to do hybrid boost control with that....could just be the bcs...
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Old 11-29-2009, 08:41 AM   #236
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Quote:
Originally Posted by LittleBlueGT View Post
What temps have logged in?
well, whatever temp swings you'd see in new england over a period of >5 years.

Quote:
Most of the MBCs really do look the same in terms of construction, I am not sure what the differences would be.
the material that the tension spring is made out of makes the biggest difference wrt repeatability at various operating temps. the quality of the seal of the ball on it's seat is also an area where it matters.

Quote:
Originally Posted by 02RexWI View Post
I've got an update for you guys on the plugging of the bleed port of the GM BCS. While it is true that we were loosing air through the other port of the BCS when the MBC opened, it actually had an advantage: In the past I also plugged the bleed hole of the MBC, worrying about airflow being lost, as you guys may know, this hole is to bleed some pressure to the atmosphere so that the pressure that is holding open the wastegate can be released when you let off the gas if you were just using an MBC for boost control. So now that all the bleed ports have been blocked off from that system, the wastegate isn't opening until the MBC opens, which is good, except: when the wastegate opens, it opens ALL the way right away.The boost builds up to 20 psi rapidly and then the MBC opens and the boost drops down to about 15 psi, and now that all the bleed ports have been sealed off, the wastegate stays open because the pressure is trapped in there. The boost will then slowly build back up to ~ 20 psi. So to solve this problem I believe the best approach would be to run a bleed port that has a restrictor pill in it, or just ditch the MBC, but since I have an EWG setup coming I'm just going to pull the MBC off and run the 3 port system alone until then.
guys, i can't for the life of me understand why everyone seems overly concerned about this "loss of airflow." it's TINY.

if nothing is present for the system to bleed pressure from the WGA when the MBC is closed and the solenoid is energized, then it will not work properly: as soon as target boost is reached then boost will disappear (ie, the boost will "crowbar").

in my experience this bleed does not need to be large at all, nor should it be.

Quote:
All of this messing around with the factory boost control system makes me wonder, why doesn't anyone make an aftermarket wastegate actuator for the VF series turbo's'? If someone did, they should make it easy to swap out springs, or at least have some sort of spring preload adjustment built into it.
why don't you just add a helper spring? have you seen the price of an "upgrade" wga for a VF? no thanks, i'll keep my $5 home depot spring on there.
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Old 11-29-2009, 04:47 PM   #237
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Quote:
Originally Posted by ride5000 View Post
guys, i can't for the life of me understand why everyone seems overly concerned about this "loss of airflow." it's TINY.
because we're bored? ^^

Quote:
Originally Posted by ride5000 View Post
if nothing is present for the system to bleed pressure from the WGA when the MBC is closed and the solenoid is energized, then it will not work properly: as soon as target boost is reached then boost will disappear (ie, the boost will "crowbar").

in my experience this bleed does not need to be large at all, nor should it be.
yeah, we found this out the hard way lol.

Quote:
Originally Posted by ride5000 View Post
why don't you just add a helper spring? have you seen the price of an "upgrade" wga for a VF? no thanks, i'll keep my $5 home depot spring on there.
agreed.
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Old 03-02-2010, 04:48 PM   #238
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Is it really necessary to modify your wgdc to 100% at full throttle with this hybrid setup. I have the Grimmspeed EBC with a tial 44 ewg and I want to run the Hallman MBC just to prevent overboosting when I travel since I live at over 6000 feet . Whats the effects if you dont modify the wgdc table.

Last edited by Murphdog; 03-02-2010 at 07:48 PM.
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Old 03-02-2010, 11:42 PM   #239
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Quote:
Originally Posted by Murphdog View Post
Is it really necessary to modify your wgdc to 100% at full throttle with this hybrid setup. I have the Grimmspeed EBC with a tial 44 ewg and I want to run the Hallman MBC just to prevent overboosting when I travel since I live at over 6000 feet . Whats the effects if you dont modify the wgdc table.
The reason that you make the WGDC 100% is to close the EBCS and push the air through the MBC instead. If you have less than 100% you will be using the EBCS to control the boost.
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Old 03-02-2010, 11:53 PM   #240
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If I didnt adjust the wgdc the car would function as if it only had an EBC, right? But the MBC would prevent it from ever going over a set psi. Thats all I'm really wanting the MBC for is to prevent over boost.
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Old 03-02-2010, 11:59 PM   #241
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Quote:
Originally Posted by Murphdog View Post
If I didnt adjust the wgdc the car would function as if it only had an EBC, right? But the MBC would prevent it from ever going over a set psi. Thats all I'm really wanting the MBC for is to prevent over boost.
The MBC won't prevent overboost if you set it up the way that this thread tells you too. To do that you would need to put the MBC inline with the EBCS, not in parallel. I don't know whether it would be best to put the MBC before or after the EBCS though.
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Old 03-03-2010, 12:18 AM   #242
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Quote:
Originally Posted by Kjott21 View Post
The MBC won't prevent overboost if you set it up the way that this thread tells you too. To do that you would need to put the MBC inline with the EBCS, not in parallel. I don't know whether it would be best to put the MBC before or after the EBCS though.
Thats not true, if you were to put the MBC in parallel with the 3 port BCS and set the MBC for whatever pressure you don't want to go over then it would work. Think about it this way: if you were spiking over 20 psi to 23 or whatever and didn't have a way to tune your 3 port BCS to solve the problem then you could just put the MBC in parallel with the BCS and set the MBC for 20 psi and the MBC would open up at 20 and open the wastegate thus preventing over-boosting. If you were going to do this setup I would recommend plugging the hole in the MBC, otherwise its may cause a problem with your 3 port BCS's partial throttle boost control.
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Old 03-03-2010, 12:26 AM   #243
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So how would I hook up my Grimmspeed ebc with a hallman mbc and my ewg. I found this diagram in this thread, what would I havee to change.
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Old 03-03-2010, 12:48 AM   #244
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Quote:
Originally Posted by Kjott21 View Post
The MBC won't prevent overboost if you set it up the way that this thread tells you too. To do that you would need to put the MBC inline with the EBCS, not in parallel.
You're mistaken.
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Old 03-03-2010, 12:59 AM   #245
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Quote:
Originally Posted by Murphdog View Post
So how would I hook up my Grimmspeed ebc with a hallman mbc and my ewg. I found this diagram in this thread, what would I havee to change.
Without checking the port numbers on the 3 port MBC that looks correct. But like I said, i'd plug the hole in the MBC that bleeds pressure since you're running it like this.
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Old 03-03-2010, 01:02 AM   #246
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This is how GrimmSpeed tells you to run their EBC to an EWG. So does the diagram above still look correct?

Last edited by Murphdog; 03-03-2010 at 01:13 AM.
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Old 03-03-2010, 01:21 AM   #247
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Originally Posted by Murphdog View Post
This is how GrimmSpeed tells you to run their EBC to an EWG. So does the diagram above still look correct?
The way that is routed you'd definitely have to be tuned for specially. It is better to run it that way, because increasing pressure to the top of the diaphragm keeps the wastegate shut allowing you to build boost faster, but there is no way of running with an MBC in parallel in that configuration to stop boost spikes.

Last edited by 02RexWI; 03-03-2010 at 01:34 AM.
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Old 03-03-2010, 01:32 AM   #248
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Yeah I'm tuned for the GS EBC. Looks like I'll need a retune to do the hybrid setup.
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Old 03-03-2010, 04:06 AM   #249
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Quote:
Originally Posted by Kjott21 View Post
The MBC won't prevent overboost if you set it up the way that this thread tells you too. To do that you would need to put the MBC inline with the EBCS, not in parallel. I don't know whether it would be best to put the MBC before or after the EBCS though.
Quote:
Originally Posted by 02RexWI View Post
Thats not true, if you were to put the MBC in parallel with the 3 port BCS and set the MBC for whatever pressure you don't want to go over then it would work. Think about it this way: if you were spiking over 20 psi to 23 or whatever and didn't have a way to tune your 3 port BCS to solve the problem then you could just put the MBC in parallel with the BCS and set the MBC for 20 psi and the MBC would open up at 20 and open the wastegate thus preventing over-boosting. If you were going to do this setup I would recommend plugging the hole in the MBC, otherwise its may cause a problem with your 3 port BCS's partial throttle boost control.
Quote:
Originally Posted by NSFW View Post
You're mistaken.
I guess I am confused. Setting up the boost controller and solenoid the way that ride5000 shows only directs the pressure signal through the MBC when the solenoid is at 100% duty cycle. How would that solve an overboost problem when the WGDC isn't set to 100%.

This is what I was answering:
Quote:
Originally Posted by Murphdog View Post
If I didnt adjust the wgdc the car would function as if it only had an EBC, right? But the MBC would prevent it from ever going over a set psi. Thats all I'm really wanting the MBC for is to prevent over boost.
In order to get rid of the overboost whether your are at partial WGDC you would have to put the MBC inline with the solenoid so that it worked regardless of the duty cycle on the solenoid. Right?
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Old 03-03-2010, 04:51 AM   #250
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Ken (the stupid one, not Gilbert), what did I tell you earlier? Google 'path of least resistance'. And let me repeat myself. PLEASE stop posting so damn confidently in technical threads.
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