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profec b spec 2 boost controller

Old 06-09-19, 01:09 AM
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profec b spec 2 boost controller

so i've been dealing with what seems like an untraceable issue regarding this model boost controller. When i pulled the car out of storage, it looked as though the boost controller settings had "reset". Sure, I know the car for the most part, I'll figure out what I need to change in order to achieve the lo-hi boost I had prior (12/14, respectively). I run a single t88 stock port with an EWG and a ~9psi (maybe 9.5) spring. I have been dinking with this thing for the past 2 months, and have had nothing but chaotic trouble. I've tried so many combinations of set/gain/set gain/warning that I'm out of ideas. Does this model head unit happen to fail commonly? I verified all of the plumbing to-from the t, wastegate, solenoid, and back of unit; none of them seem to be damaged, and the mechanical reads in line with what the last-boost is showing on the unit. When the unit is turned to *OFF*, as long as I haven't dicked with lo-hi during the drive, it seems to properly disable the boost controller and go to spring and hit a happy 9.2-9.5 all day. When I do mess with the settings, and swapping between lo-hi, changing set/gain, etc., it seems to just quit. It literally will not open the wastegate, period. At any combination of set/gain/set gain(start boost i guess?).

I have been smart enough to do rolling pulls in 2nd and 3rd and let off on anything over 18, attempting to figure out what the hell is going on with this thing. One thing I have noticed is that I cannot get the gain to go below 5% (this might be correct, but I have read in multiple posts here and other places of people using 0 gain. Maybe i'm misunderstanding what they're referring to). I have tried any combination of set% between 10% and 40%, as well as gain between 5% and 30% and start boost between 90-130. they all do the same thing and just ignore all settings and skyrocket boost to the point of having to let off the throttle ~17psi. I have verified it is not in kPa (at least the lcd isn't lit up to display that) and the percentages and info seem to "make sense". Granted, I am not entirely sure I understand the basis of the set% and how that number is calculated, but whatever; I've went through the entire array of percentages using multiple values of gain and start boost. Is there something blatantly obvious I am missing with this controller, or is it likely something in the head unit is done for? (side note; I replaced the solenoid about 2 years ago due to it locking up. I have since verified as of a couple days ago that the current solenoid seems to be operating properly at voltage.) Any insight is appreciated, as I'm at my wits end for this thing. I would gladly go with a more reliable unit versus gambling any harder with the motor than I already am trying to troubleshoot this one.
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Old 06-09-19, 07:59 AM
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A very long time ago, over 10 years when I installed mine; I used a small tank of compressed air along with a regulator or two to test the system in the garage vs boosting the turbo. I don't recall what settings I used and no longer have it.
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Old 06-09-19, 09:54 AM
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That is strange, those boost controllers are typically pretty hardy.

You should be able to bench test it, use pressure on the pressure sensor and you should be able to hear the solenoid cycling. Could also be something with the wiring if something got damaged or shorted out.

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Old 06-10-19, 10:16 AM
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i was able to bench test it at the head unit at least and definitely heard the solenoid cycling when it hit warn levels. I wasn't able to do a ton of "accurate" psi pushes since the source was coming from a 150psi tank and I had to very steadily push air from the chuck, so i was at least able to test between 1-20psi. The unit itself seems to function properly at a standstill, and I even ran the car while I tested at the head unit and it seemed to respond properly. I however have no real way of telling if 1) it is cycling prior to the warning limit (this comes back to "do i even understand the numbers i'm setting for SET/GAIN/SETGAIN?"), and 2) if i'm dealing with a compound issue (the unit seems to go haywire any time I try to change settings on the fly, i literally have to turn the car off and back on in order to "apply" changes like turning it OFF etc).

I can't seem to find consistent info, but what is set% a percent actually _of_? For example if i set "set 30%", what is it 30% of?
I am double checking a couple more things, but if anyone has any insight on this I'm still open to suggestions
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Old 06-10-19, 10:53 AM
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Could also be something with the external waste gate itself. May want to check that it can hold pressure and everything and it doesn't have a torn diaphragm. External wastegates always seem to want to act up.

Most EWG's have 2 nipples, one above and one below the diaphragm. Are you using both in how you have it connected? Or just the lower?

The manual is here -

http://www.banzai-racing.com/store_i...EC_B_SPEC2.pdf

You may want to re-read through it and re-learn how to set it up as well. I would also check your vacuum diagrams.

Dale
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Old 06-10-19, 01:18 PM
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I know that the line coming off of the pipe closest to the turbo compressor side is teed to go down there, as well as the "COM" side. I haven't 100% verified with my own eyes if they're both properly hooked up to the correct nipples but there are two down there that I have felt and both have lines running to them. so at this moment COM and the tee off compressor pipe, are both going to the wastegate, and I am "assuming" they're hooked up properly due to boost controller having worked properly in the past (prior to me finding an old coupler with a hole in it, and replacing the solenoid as it looked like **** through the "NO" hole.) I have however read people using "NO" and "COM" on ext wastegates (still can't determine what the purpose of this would be), and I checked all the little things (source of pressure to wastegate is in a good spot off turbo, so it would experience a minimal amount of pressure delay). I can probably get the car on some stands in the next 24 hours and visually inspect and pressure test the wastegate diaphragm. I am going to give this one more drive to try one more bundle of spec 2 settings that should in theory be correct for ~11psi (assuming 8.5-9psi spring). If these next few pulls fail to produce improvement, i'll start looking more into the wastegate and plumbing/setup as a whole.
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Old 06-10-19, 01:25 PM
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Also just went and verified the t off of compressor pipe is going to the bottom nipple and the one from "COM" is going to the top of wastegate nipple which doesn't seem to match the diagram, oddly; however I haven't changed these since acquiring the car (which boost worked as intended prior). Will double check shortly (i just "felt" down there after following the lines)

Last edited by fettdawg; 06-10-19 at 02:16 PM.
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Old 06-10-19, 02:09 PM
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The theory is with an external wastegate you have 2 nipples - one above and one below the diaphragm. That allows you to both push and pull the wastegate which should result in faster and more accurate response.

Since it is plumbed differently on the wastegate the actuator has to be plumbed in differently as well. There are 3 ports on the actuator, you always use one no matter the setup and the other 2 are dependent on if you have internal or external wastegate.

That said, looking through the manual, you have 3 things to adjust - start boost, duty cycle, and gain. Start boost is the pressure you want to achieve - let's say 14 psi. You set this to the actual target boost you want. Duty cycle is the percent on time for the solenoid to get there - you increase this until you hit the target, or decrease if you over-shoot. Gain is the speed of the response - if the boost takes a while to build, you can increase the gain which increases the response. If you increase it too much it can over shoot the target boost.

I would set the start boost to what you want for a low boost setting, start with duty cycle of 30% or so and start with the gain low like 10%. Work on duty cycle, get where you want, then you can tweak the gain in. I'm wondering if you don't have the start boost set up right.

I would print a copy of the manual and go through the buttons and get a sense of how to get to each setting and how to change and set each setting in the driveway. Set your target boost and base settings then go out and start tweaking the gain and see if you get somewhere.

Dale
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Old 06-10-19, 02:43 PM
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Originally Posted by DaleClark View Post
The theory is with an external wastegate you have 2 nipples - one above and one below the diaphragm. That allows you to both push and pull the wastegate which should result in faster and more accurate response.

Since it is plumbed differently on the wastegate the actuator has to be plumbed in differently as well. There are 3 ports on the actuator, you always use one no matter the setup and the other 2 are dependent on if you have internal or external wastegate.

That said, looking through the manual, you have 3 things to adjust - start boost, duty cycle, and gain. Start boost is the pressure you want to achieve - let's say 14 psi. You set this to the actual target boost you want. Duty cycle is the percent on time for the solenoid to get there - you increase this until you hit the target, or decrease if you over-shoot. Gain is the speed of the response - if the boost takes a while to build, you can increase the gain which increases the response. If you increase it too much it can over shoot the target boost.

I would set the start boost to what you want for a low boost setting, start with duty cycle of 30% or so and start with the gain low like 10%. Work on duty cycle, get where you want, then you can tweak the gain in. I'm wondering if you don't have the start boost set up right.

I would print a copy of the manual and go through the buttons and get a sense of how to get to each setting and how to change and set each setting in the driveway. Set your target boost and base settings then go out and start tweaking the gain and see if you get somewhere.

Dale
interesting, i've read in places that the "start boost" is basically when you want your wastegate to "come online"; in a sense, you set this lower (usually 3-4 psi) than your desired boost, and that's what i've taken as law. In a nutshell, here's what i've been trying

spring: 9psi (For reference)

lo: set-35%, gain-5%, start boost(set gain)-100(10psi), warn-130(13psi), limit - 7%
hi: set-65%, gain-5%, start boost(set gain)-120(12psi), warn-150(15psi), limit - 10%

what you're saying is if I were to want to achieve 12-14 lo-hi, i would need to set the start boost(set gain) to 120 and 140 for lo / hi respectively, and start with 30% set/5% gain? I can definitely try the settings you suggested. Thanks for the insight so far, I will report back.
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Old 06-11-19, 07:51 AM
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I don't have direct experience with the Profec B, so you could be right on the start boost.

If possible, try and set up the boost controller doing 3rd gear pulls. The extra load helps.

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Old 06-11-19, 10:00 AM
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i will if i can figure out the preliminary malfunction. currently it doesn't seem to operate properly at all unless its in OFF state. there is a ton of information just searching about it, but stuff like set% everyone seems to explain differently and nobody hammers down what it is a percent of. Gonna try and grab some more info and maybe test it out today
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Old 06-11-19, 10:17 AM
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The manual seemed to state the set% is the duty cycle of the solenoid. 0% = wide open, no restriction, 100% = fully closed. It's restricting the pressure going to the wastegate that opens the wastegate - if the wastegate opens at 9psi, you reduce the air pressure it gets so it opens later and you are making more boost.

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Old 06-11-19, 10:57 AM
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interesting, i always thought it referred to a % of your spring pressure. Maybe now that I think about it, i need way less duty cycle (maybe 15-20%) because my boost seems to have zero issue getting up there and overboosting...
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Old 06-11-19, 02:15 PM
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Remember, the boost controller is relatively dumb, it has no idea what your spring rate is or anything. You're just setting up how it cycles that solenoid.

You do want to sneak up on the final number, start at a low number and go up by 5% or so until you start getting close, then 1%.

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Old 06-11-19, 04:57 PM
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small update since i had the car inthe air:

confirmed that the COM port side is going to the top-most nipple, and the T side off compressor housing is going to the bottom nipple on wastegate.
tore the dump pipe off wastegate, confirmed the wastegate was fully opening and closing (it actually operated as if it were brand new, i was surprised how cleanly it actuated opened and closed.)

I haven't drove it yet today, plan on it in a bit. I am going to set all of the numbers incredibly low (cycle maybe 5%, gain as low as possible, 8.5-9 start boost, 12 warn) and see what happens, and try to dink with it from there. will report back
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Old 06-11-19, 05:20 PM
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drove it at near 0s across the board still spiking well past what I care for. Maybe a bad head unit? It seems to read boost consistent to my mechanical. Both of my solenoids are behaving the same way so unless I have 2 fouled solenoids I would assume no on that... This darn thing :/
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Old 06-12-19, 11:13 AM
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i am wondering if the signal wire is faulty to the solenoid from the head unit? I randomly noticed someone had mentioned this in another forum. I know the signal is there in some aspect, as I confirmed it had some level of bleed-off when it hit the warning on the head unit testing that itself (had second person monitoring solenoid and attempting to put air through it with bike pump). I know for a fact that the white-green signal harness is stretched basically to the max sitting in the cubby where it's at, so i'll check that i guess
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Old 06-12-19, 11:25 AM
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Could be. I think the solenoid itself just has 2 wires that drive it.

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Old 06-12-19, 04:04 PM
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correct yeah i think the head unit "harness" basically goes directly to it to provide voltage to trigger the solenoid. will be testing this shortly actually
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Old 06-12-19, 06:43 PM
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so tested solenoid on ohms, get a reading of like .36 or something. tested from harness plug to solenoid, same reading. so seems the cable is good. when i volt test the harness from the head unit, i get 0 voltage even well after breaking past the limiter (what should be triggering most of this). so I am gonna try and source another profec b spec 2 head unit and see what happens
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Old 06-21-19, 06:12 PM
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New head unit installed, everything is golden. darn thing
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Old 06-24-19, 10:07 AM
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Weird! Glad you figured it out! Something must have gone bad in that unit - leaky capacitor or something got zapped in a power spike or something.

So it's working totally normal now?

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Old 06-25-19, 10:17 AM
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yup! after seeing good ohms from harness unit-side connector thru solenoid, and not getting any voltage pickup at the solenoid connector when i was throwing > warning limit air pressure at the original head unit, i assumed the head unit must be shot. After swapping in a new head unit and setting some pretty basic boost settings, i was able to immediately tell it worked better because i heard the solenoid clicking in a cycle fashion when sending psi to it. have driven it 3 times and was actually able to even butt tune my old lo/hi settings back into place. Thanks for all the insight!
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