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3 port BCS, flutter. ATTN: curtis!

4thStroke

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Oct 22, 2007
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Vancouver, WA
I'm getting a lot of flutter when the wastegate opens up. I'm tuning with ECMLink.

The car has a bolt on FP HTA GT3076R, FP race manifold, Ingersoll Rand 3 port solenoid (recommended by ECMLink) TiAL 44mm v-band waste gate with vacuum lines ran to both ports per ECMLink instructions.

When the BCS reaches the target duty cycle, the wastegate flutters. The pulls aren't nearly as clean as they should be, the AFR is unstable, etc. Originally, I had one line ran to the bottom port, running both lines helped a lot.

I have not gotten any hits about this on the ECMLink page, so I figured I'd post it here. Some guys on EvoM have had the same issue with certain solenoids, but I seem to be the only one having this issue with this valve which is supposed to be one of the better ones.

Not my car, but here's a video of what it sounds like, posted by an EvoM member click

ECMLink users are having good luck with even small springs. I did not have any issues with the Perrin MBC. I'm hoping I can resolve this without having to buy $50+ in springs for a possible solution.

I'm posting here, hoping a member has experienced something similar, whether it was on the DSM platform or not.
 

curtis

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May 4, 2003
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Clarksville TN
First how much boost when it starts?
where is the gate located on the manifold?
Is the bov a Tial
Is it vented back in if its not?
Have you tried disconnecting the bov and capping the hole eo see if it still does it?

44mm should be fine. My buddy had a tial BOV on a 2.5 subaru that did the same damn thing so it may be the bov more than the gate. He's had other cars in his shop that did it as well. Alot of times its location more than just the valve. if the air is traveling in the pipe in such a way its smacking the valve it will open and flutter. On his I simply moved it up about 6 inches and on the opposite side of the pipe and it almost quit and then he said screw it and put on a HKS and it was gone except the normal flutter they do. This is the main reason I bought the synchronic stuff for mine. I have two of the bov's and a 50 gate so I should have zero problems.

Something else whats the ar on the turbine and what size exhaust it could be the gate but if the turbine pressure is exceeding the intake side pressure the differential may cause some of this.

I'll look at your replies later.
 

4thStroke

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Oct 22, 2007
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Vancouver, WA
It starts when the gate is called to open. At spring pressure (about 15psi), operation is normal. Once I turn the boost up (BCS is active), it flutters, whether it be 18psi, 20psi, 25psi, or even 28psi.

The gate is on the hotside. It has the FP bolt on housing, so the flange is cast into the hotside. I can't recall what the AR is, but it fairly small.

The BOV is a Forge. I've had great luck with them in the past and it always worked well. I do not suspect it to be the culprit. My AFR is a little erratic, which shows in the log, it's not smooth. With the external dump, the fluttering is very pronounced.

The exhaust is full 3". There is a Magnaflow resonator at about the halfway point and a 3" in/out Magnaflow muffler. I even shelled out for the full 3" FP v-band O2 housing. No cats.

Car is on speed density, recirculating the BOV won't make a difference.

The car operating perfectly fine (in this regard) until I tried the ECU controlled boost. It was the only thing that was changed. I know that if I switched back to a MBC, the fluttering will go away.

To me, this makes sense. Since the BCS is opening and closing, it sends pulses to the wastegate, but this effect seems to be amplified to the point it's obnoxious and hindering. It seems maybe it needs to operate at a higher frequency.

Thanks for the input, curtis!
 
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curtis

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Well Something that might make no sence but I think it will work. Manual controllers work on a bleed air situation. It pushed against the diaphragm and excess is bleed off but there's enough pressure on the valve and to the diaphragm to make it stable. On the 3 port ingersal rand you have it may not have a bleed so whats happing in stop motion is the valve opens and the vlve sees the pressure is where it needs to be and closes then opens then closes and flutters. Maybe a bleed on the circuit to the valve is needed. Another circuit to the top of the diaphapm for differential pressure is needed or maybe a slightly smaller tension spring on the gate. All or a combination should do the trick but I really think a small pin sized hole in a hose connector would bleed out enough to counter act whats going on. Seems logical that the ecu sees that the map is saying x psi want your input to the computer says is also x psi so everythings happy and it closes then milliseconds later it its says oh sh*t were below x-3 and it says can't have that and does its thing all over again.


I've never been a fan of manual controllers since I can't just reach down and go into overboost mode but in this situation seems like a better way to go except after the bugs are addressed this should work better and spool up faster since like we've stated a manual is just a bleed.


What we really need to know is manifold pressure on the intake side, turbine housing pressure at the gates valve and pressure on the wastegate diaphragm. to see whats causing this. I figure at 18 on the intake the gate diaphagm is probably really close to that but with a small housing you may be seeing 25 or so on the 44mm valve and its forcing it open.


I think my first thing I would try is putting a line on the top and bottom of the diaphragm to equalize the pressure. tricks can be done with this as well like reference one from the intake and one from the compressor housing dependent on IC size and flow of the pipes maybe 3 psi more. When I set up my profec A on my car I played these silly games for 3 days to get it dialed in. Actually the way I fixed it I referenced it from both the intake and compressor and joined the two together. Didn't think it would work but it was perfect after that.
 

4thStroke

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Thanks again for the input, curtis. I'll play around with it more and see what I can do.

As for equalizing the pressure on both sides of the waste gate, should I splice in a T fitting on both vacuum lines and rout a hose from one T to the next?

I just got done talking with Brummell, the only thing that I did not follow by the book was the boost reference point. I'm drawing from the intake manifold, tomorrow I'm going to drill and tap the boost source at the throttle body elbow.
 

DynastyLCD

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May 12, 2006
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761
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Harwinton, CT
this is interesting to me, because ive been dealing with the same issue.

my setup: FP3052, tial 44mm v-band gate, tial 50mm BOV. boost is set to 27 psi, if i try to spool it as low of an RPM as i can, when it first hits 27 psi around 4k, it will flutter a few times where it sounds like the gate is rapidly opening and closing for a second. this only happens in the higher gears, 3rd, 4th, 5th. 1st and 2nd are so quick it just dosent happen. only when im trying to spool the thing from a low RPM. ive only got a 1 bar spring in there, maybe its time for more.

judging my issue, it seems like the wastegate cannot keep itself open at some points. is this the problem you seem to be having, 4thstroke?
 

4thStroke

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Kinda. But I'm able to replicate it in every gear, for as long as the wastegate is supposed to be open. As it builds boost, if I keep an eye on the boost gauge, it's still fluttering. In that respect, it seems like the gate fails to stay closed, but I think it has more to do with the duty cycle of the BCS.

What are you using for boost control?
 

brisvr4

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brisbane australia
I'm using the same bcs setup on mine but I use the compressor housing as the boost reference point and I have no problem with what you have described.
The wastegate us a PTE 46mm unit and I'm running a 1 bar spring in
It, turbo is a 6262 .82 rear. Boost is right around 30psi and holds rock steady.
 

curtis

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^ what size hose from the compressor housing to the controller and what size from the controller to the gate. That maybe a problem their having as well.
 

curtis

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Larger would be more volume and also longer would be more so that might slow the rate of change down. /ubbthreads/images/graemlins/dunno.gif Can't remember what worked correctly on mine but I did change out sizes a few times.
 

brisvr4

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brisbane australia
All the same size here, it measures up between 5 and 6mm which is pretty close to 7/32.
I do have the bcs very close to the gate so the hose runs are quite short.
 

4thStroke

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My BCS is also very close to the gate. Someone mentioned that the larger volume lines take longer to respond to changes which would not play in my favor, but the barbs are 3/16" and we all know the barbs on the wastegates are rather large. I don't think that by me being 1/32" larger would be enough to make much of a difference.
 

brisvr4

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brisbane australia
Have you tried hooking your mbc back up to see what happens?
Also, what settings do you have in link for the Lock at 0% below and Lock at 100% below?
Probably doesn't help at all but can't hurt to check.
I did notice that I got a stuttering at around 22 psi when I first set everything up and it turned out to be a torn spark plug lead boot.
It sounded just like the video that you posted! Changed the boot and problem solved.
 

DynastyLCD

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Harwinton, CT
Quoting 4thStroke:
Kinda. But I'm able to replicate it in every gear, for as long as the wastegate is supposed to be open. As it builds boost, if I keep an eye on the boost gauge, it's still fluttering. In that respect, it seems like the gate fails to stay closed, but I think it has more to do with the duty cycle of the BCS.

What are you using for boost control?



hallmann pro, which is getting its source directly from my vacuum block. ive been considering swapping to a dual spring, as i dont plan on running below 20 psi. that would put more spring pressure on the gate, and possibly eliminate the fluttering during prolonged spooling it sees in 3rd 4th and 5th. but once it does finally open and stay there, everything is kosher.
 

brisvr4

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brisbane australia
I just took mine out for a spin. 30psi and rock solid boost. No flutter at all.
 

1qkfwd

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Sep 29, 2009
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Sun Valley, NV
Just a couple rules to follow when hooking up any boost controller up. First never tee into or have the bov on the same line. Second run your boost source as close to the turbo as possible. Most compressors have a flat spot to drill and tap for at least a 1/8 npt hose barb. I've always done this and never had any issues and turbos always spoolup fast. Like my buddies 16g we just drilled and tapped the j-pipe next to the flange since the mitsu compressor wasn't to friendly about us pulling it off to tap it out.
 

DynastyLCD

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interesting. do you think the flutter problem in my case is from the source, as its coming all the way from the manifold?

edit: just watched the youtube video 4thstroke posted in the first post. my issue happens for a split second, a few flaps open and closed, then it hits its desired boost level and stays. doesnt surge the entire way down the road like the video shows.
 
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