Boosting issue

[Ian91]

hi all

As some you are aware from my previous threads I am having abit of a boost issue.

Specs of car

93t
Td05 w/ 3' front cover, gt pumps rear.
38mm external w/g
Evo afm
Evo 560cc injectors
Evo 3 ecu, chipped and written to run the 93
Insight Motorsport bcu
300e coil on plug setup.

Ok so the car gets to 10psi of boost once there if you keep on the throttle it will start to oscillate the boost as if the waste gate is doing what it should by opening and closing and keeping the boost at my desired level.

However 10psi isn't my desired boost level, the ebc is set at 12 or 15 ( I can't remember what exactly but I know it was higher than 10)

I have setup the duty cycle and target boost etc on the controller as per the instruction. I have plumbed the waste gate like below, can anyone tell me if this is the correct way it should be plumbed and if not how have you got your setup? Because I feel everything else is right but the ebc just is controlling the w/g properly for some reason.



Thanks guys

 

[MDK87]

I'm guessing it's a closed loop controller?
Is there a ramp function? Sounds like it's a little slow to respond. The boost pressure shouldn't visibly oscillate on your gauge.

 

[White Knight]

Irony... My name is Ian as well and I have boost issues as well and Mo was trying to help me today.
Try simple things, check the direction of flow for the solenoid is correct, is power getting to the solenoid? (When switching ignition to "on", do you hear it tick?).
Probably something stupid but simple.
Also, change the ebc settings slowly (increase duty) as the settings you were provided maybe for a totally different set up as well.
Cheers and best of luck mate.

 

[Ian91]

I'm guessing it's a closed loop controller?
Is there a ramp function? Sounds like it's a little slow to respond. The boost pressure shouldn't visibly oscillate on your gauge.

When you say closed loop does that mean it doesn't talk to any other parts of the car?

It doesn't have a 'ramp function'.

Haha I know it shouldn't, can see it on the gauge and very easily hear it oscillating, also you can feel it.

Ian, the solenoid was actually wired backwards (Durr, both the wires are black) so it was doing nothing previously. This morning I switched the wires around because I suspected it may have been the issue. Took it for a spin and it was better but still oscillating.

That's why I wanted to check I had the waste gate plumbed right because it's either the waste gate plumbing or the ebc just isn't quite right yet.

If anyone can confirm the wg is right I'll keep fiddling with the ebc setup

 

[evo-gsr]

What does it do without using the ebc? Have you tried that? That will tell you if the ebc is the issue or the way the gate is setup.

 

[MDK87]

This ^

Closed loop means it references a pressure sensor and you said you dialled in a target boost level so I'm guessing it must be.
Ramp might be called gain or something else.. Basically it's how quick the controller works towards the target level.
What you're describing sounds like a system that is underdamped (see pic below).

The first thing I'd be doing is removing the EBC and running spring pressure to see if the oscillations are EBC related.

It's not surge is it? Do you have a BOV? Does the 3" cover have the 'anti-surge' ports in them?

 

[Ian91]

Haven't tried it with no ebc, do I just connect the nipple on the front cover straight to the bottom port of the wastgate?

The ebc has a gain function, I have adjusted it but perhaps not enough.

Yea the front cover is an anti surge one

 

[khubner1]

you would have to refer to your instruction for a spring pressure only setup

 

[MDK87]

Haven't tried it with no ebc, do I just connect the nipple on the front cover straight to the bottom port of the wastgate?

Yes. leave the top port open.

 

[DOUGMO]

i would just run it as a bleed, from the bottom of the gate to the turbo, leave the top open

 

[Ian91]

i would just run it as a bleed, from the bottom of the gate to the turbo, leave the top open

How does the ebc solenoid fit in there? Port 2 to the gate and port 3 to the turbo nipple?

 

[evo-gsr]

i would just run it as a bleed, from the bottom of the gate to the turbo, leave the top open

Pretty sure thats how mine is also, from memory.

 

[Ian91]

Pretty sure thats how mine is also, from memory.

Could you take a pic of the way yours is plumbed if you have a chance?

 

[DOUGMO]

just run a single hose from the compressor housing(boost signal) to the bottom of the wastgate.

fit the bleed vave into this line. it depends on what solenoid you have but it will have 2 x ports and a vent port.

same as the diagram above but on a single hose. what this does is bleed the boost off so the gate sees less and will increase the boost level

 

[DOUGMO]

 

[brisvr4]

What ebc and solenoid. It shouldn't matter which way the wires are setup on the solenoid, one sound be 12v and the other a switched ground from the ebc.
I wonder if you have the Potts on the solenoid plumbed incorrectly?
Do you have a pic of it?

 

[bazeng]

You have a few ways to do this.
Bleed method only works on actuators with a nipple under the diaphragm.

Simple to setup. Just like a boost t valve. Only downside is that it allows the valve to open prior desired boost target.

This means you will make less power down low.

If your boost controller supports it, you can get to bleed 100 percent until desired boost is achieved then switch to allow pressure to the gate. But this will usually see some sort of spike on activation.

The benefit of feeding the top of the actuator is that the pressure assists the spring meaning you can make full boost then the valve will open. Control is also superior bleeding off the top.

Ideally though, you want a spring that closely matches your target boost for best control.

Question, do you have any restrictors installed?

Have you done the basic tests to ensure you have things connected right?

Example, disconnect hoses from valve. turn on ignition. Blow into the port. Write down which ports are linked. Activate valve (software or hard wire) blow though, it should change. You should have one common port. This goes to your turbo pipe. The normally open (first test) goes to your top. The 2nd when activated goes to free air.

So when not activated it goes to your gate. When activated it bleeds to atmosphere.

Alternatively you can do the reverse via settings. This allows the valve is it was to fail to always bleed meaning spring pressure.

Keep in mind software settings may affect polarity and may cause it to be open when it should be normally closed.

Quite a complex subject sure to various methods utilised. Software is key in my opinion.

 

[Ian91]

Thanks dougmo, it is a 3 port MAC solenoid, supposed to be quite good I think.I'll try that setup after I do what Brian said and work out which port is which on the solenoid. I will also run the bottom port of the gate straight to the front cover and see what it does.

Brisvr4 the ebc is this one, and the instructions that came with it said if wired one way it won't work and if wired the other way it will. Maybe this solenoid is different to normal ones?
http://insightmotorsports.com.au/products/Insight_BCU_Version_2_0-93-1.html

 

[brisvr4]

Shouldn't be Ian. Can you post up the instructions?

 

[Ian91]

Shouldn't be Ian. Can you post up the instructions?

Might not have been in the instructions, I had a few emails from Scott at insight too, I'll have to take photos of the instructions because I don't have a scanner lol