Electronic boost controller woes
 

To start off, I finished up installing my used Greddy profec b spec II boost controller three days ago, and I believe I throughly understand how to "tune" it from reading on here, and the manual. However, since installation, I have been unable to get it to boost above the "stock" level; 7psi in the case of the profec b.



I used the second method to install the solenoid:

https://www.rx7club.com/forum/attach...&postid=952472

and currently my settings on "HI" mode are:
SET: 60%
GAIN: 10%
SET GAIN: 110
warning: 131
warning limiter: 9%

At wide open throttle in any gear both my boost gauge and the profec b show the max psi to be about 7, sometimes a little less.

Yes, I have checked to make sure the controller is in "on" mode
Yes, I have checked all of the vacuum lines, "in" being "NO" on the solenoid, and "out" being "COM" on the solenoid. (according to the diagram above)
Yes, I have tried various settings, all to no avail.
Yes, I removed the pills

If anyone could point me in the right direction here, that would be awesome.

Note: I'm not sure if its relevant, but in vacuum, the profec b and my boost gauge vary greatly, IE: boost gauge vacuum reads -17psi, profec b reads -80 (indicating -8psi)

How did I know this would be the Spec II?

Probably not what you want to hear, but look into the Type-S version. Much simpler and better boost control. Start reading at post #25:

https://www.rx7club.com/showthread.p...2#post10079462

This is what I was afraid of. I just ordered a manual boost controller, Thanks for the help, it's much appreciated.

What mods do you have?

petit ecu, downpipe, highflow cat, apexi gt spec catback, and intakes

GoodfellaFD3S, why do you hate on the Spec 2 so much. Everyone that I know that has used this boost controller is trouble free including me and its always an easy setup. The old version is the EXACTLY the same settings except you control them with analog knobs instead of with precise numbers and you have added features like warning limiters that can reduce boost by a programmed amount, log peak boost, and be used as a boost gauge eliminating the need for one. Just because some people have issues, doesn't mean there is something wrong with it. Only that its an electronic device, failures happen, the Spec-S is no exception. Now on to solving the problem instead of telling someone to go buy something else...

You can ignore the Profec's vacuum reading, its pretty useless. Here are the settings you need to use...

Set: start at 20% and raise it until you get desired boost level
GAIN: 5% (you don't want to go too high on this or you will get unstable boost)
SET GAIN: 70
warning: 131 is fine
warning limiter: 4%

Now are you positive you connected everything properly? Did you buy the unit new or used? Was boost working properly before you installed the boost controller? Can you verify that the boost solenoid is functioning by giving it 12 volts and see if it clicks?

thewird

Marco, I've already explained my viewpoint to you, and I've been helping FD owners in this community solve their problems long before you were on this site. Show a little respect to your elders ;)

OP, I'm curious to see if these settings help you any, please let us know what you find out :icon_tup:

Boost gauges read in inches of mercury in vacuum. 30" mercury ~ 14 psi. So I think they read the same.

If you searched old posts on this site, you would see 1000% more threads with people asking how to set up the Spec 2. You have only a few for the Spec 1 or Type S since its more idiot proof.

So definitely not "trouble free" "easy setup". :nod:

The Spec 2 is less intuitive than the other Greddy controllers, yes, but assuming there are no hardware failures it's not that bad to set up. Also, the Spec II works similarly to most of the other external boost controllers which have a digital display and use 3 port solenoids. There's very little difference between a Spec II and an AEM Tru Boost for example, except that the AEM is open loop only (has no gain setting).

To the OP, here's a question: do you have it in PSI mode or kPA? It sounds like it could be in the default kPA mode. That can affect things greatly. Also, I think your SET GAIN (aka start boost) is too high, especially if you have it in kPA mode. With a setting of 130 you are holding the wastegate shut until 11 psi or as much as 16psi (if you have it in kPA mode). That's going to screw things up. Try keeping the GAIN very low (like you have it now). Then starting from scratch incrementally raise the SET and SET GAIN and see what happens. Adjust the GAIN last.

Also, what is the pressure source for the line going to the Spec II box? What is the pressure source for the boost gauge you are running?

The instructions aren't exactly the best and is probably the reason for all the questions. Once you understand it, you realize its actually quite simple. Now the AVC-R, theres a complicated one but it has the ability to tune by RPM and gears which is an awesome feature but is time consuming and I don't really like the bulkiness of the unit lol.

Having said that, I don't think the settings are the owners problem and only mentioned them for once he gets it working. The settings he had should have raised boost and not run wastegate pressure. Its either the way he has it hooked up, faulty solenoid, or something else wrong like a wastegate actuator clip falling off.

thewird

^^^what he said.

60% gain should be way over waste gate pressure as I run the same unit at 32% to get my desired 13psi.

7 psi is basically the default setting, ie boost controller turned off. As has already been mentioned, it's either an install problem or a hardware problem. Good luck with it ;)

You already purchased the boost controller so you might as well try the settings thewird mentioned above.

He set mine up, and it's working well.

im not a huge fan of that controller either, i got the type s.. my brother got that one and i hated setting it up for him

I used clamps on every vacuum hose end, and teed them off properly to the wastegate and precontrol solenoid.

The unit was used, but I purchased it from a good friend and I really doubt he would screw me over.

Boost was working properly before, with the exception of spikes to 15psi.

I will try giving the solenoid 12 volts and check for a click.


Psi mode.

The pressure source is the same for both; The empty nipple on the UIM. I have a T fitting just after it and they both receive readings from the same spot.



I'll give the settings posted here a shot later today.

Your boost gauge most likely reads vacuum in inches mercury. There are about two inches mercury or 25 mm mercury for every psi. With a reading of -8psi on your Profec you are reading about 16 inches or 400mm mercury . If your external boost gauge is reading 17 inches mercury, when compared to the 16 inches reported by your Greddy EBC that's an acceptable difference. I had to get used to doing all these conversions in my head from dealing with so many different systems. For example, on the Cobb Accessport for tuning Subarus etc the vacuum is displayed in psi as opposed to inches mercury. So when an STi is reading -10psi in vacuum, that's about 20 inches mercury which is what you'd expect from a stock engine with only mild modifications.

I hate having gauges disagree. I read boost off my Power FC commander only. It uses a calibrated GM MAP sensor. There are no external boost gauges or boost controllers--all boost reading and boost control is handled through the PFC so there are no discrepancies.

With the solenoid at rest (not energized), air should pass from the NO port to the COM port. With the solenoid energized air should pass from the NC port to the COM port. This is how a 3 port solenoid valve works. It's just like the 3 port solenoids used in a lot of other boost controllers. It's also just like most of the OEM solenoids in the rat's nest (such as the charge control solenoid).

well, I tried the settings posted here, and even upped the first % to 60 and no change.


From what I'm understanding, the NC port should be left open, the NO port should go to the turbos, and the COM port should go to the actuator.


I did not try giving the solenoid 12v. However, the controller is receiving power from one of my electrical fan switches, which receives its power directly from the alternator, with a 30a inline fuse. Would this wiring cause any problems?

Did you try the "Version 2" plumbing?

Yes, in my first post I said I used the second method. I don't see any point in trying the first method either, if its supposedly more problematic.

I have the Blitz R-spec boost controller and tried version 2. In this version, when both turbos are on full boost, it was the Blitz that controlled the boost. It was unpredictable and spiky, at one point jumping to 19psi. Luckily I had water injection so didn't blow my motor.

I ended up using version 1 and the boost was more predictable because when both turbos are on after the transition, it's the PFC that got a much tighter clamp on boost pressure.

Please report back when you have tested your solenoid.

thewird

no boost
 

Hello there I am new here and have a serious issue , similar to what other people are experiencing

I have a 1996 FD with a ported engine , 3mm apex seels , single HKS T04E turbo kit and many many more stuff

My problem is setting up my Greddy Profec B spec 2

I want to run about 1.25-1.3 bar of boost

I have tried to set the gain between 15-25% , the set gain from 0.5 bar up to 1.05 bar and the boost from 50% up to 70%

All it does in all gears is to hit an overboost of 1.35- 1.4 bar and then it dies straight away to 1.1bar

So , what I am trying to say is that no mater what I do I cannot see constant , steady boost above 1.1 bar no matter what settings I dial in

ALL my connections and settings are ok

Please help

what size wastegate?

i think its 40mm

After 1 week of endless test runs I got these settings

boost : 68%
gain : 6%
set gain : 0.6 bar

this gave me 1.2 in first and second dropping to 1.1 , 1.35 in 3rd dropping to 1.15 and 1.4 in 4th dropping to 1.2

This was good enough to hit 4th @ 300m in a quarter mile run exiting with 11.89 @ 210kph

I will give it a rest, if it doesnt want to hold more so be it