Jump to content
SAU Community

Boost controller/gate plumbing

r34.rory

By r34.rory,
in Engines & Forced Induction

 Share

Recommended Posts

r34.rory Enthusiast

r34.rory

Posted
Posted

What’s the best way to plumb the gate to my greddy profec b spec 2? before I changed to a sinco manifold I had this as shown in the pic. But never got to try it/dyno it as I changed up to a sinco twin scroll and different wastegate. Most pics/build I see have only two lines to controller and the third is vented to atmosphere. I’m not looking for anything crazy. 400-500bhp but prefer response.

should I just ask my tuner how I should plumb it? 

—————————————————————

RB25DET NEO

Holset HX32 twinscroll

sinco twinscroll mani

profec b spec 2

turbosmart ultragate 45mm 14psi spring 

6C7CC8DC-F7F0-452F-965F-D687C70C716F.jpeg

Link to comment
https://www.sau.com.au/forums/topic/479692-boost-controllergate-plumbing/
Share on other sites
r34.rory Enthusiast

r34.rory

Posted
  • Author
Posted
10 hours ago, KiwiRS4T said:

Why not follow the instructions? But have you got an aftermarket ECU? I would use that to control boost.

That’s the thing I was. I believe that’s a turbosmart diagram. But I see so many people just venting to atmosphere instead that’s what made me question it. Yeah but Nistune.

GTSBoy Grand Master

GTSBoy

Posted
Posted

It works out like this. External gate can have a weak spring, or it can have a stiff spring.

When it has a stiff spring, it will want to close quite well, so it doesn't need any help. So you leave the 3rd port of the solenoid vented to atmosphere and you plumb the 2nd port on the solenoid to the side of the wastegate actuator that will make it open.

When you have a weak spring on the wastegate, you will probably need to help it close, which is what the connection diagram you posted does. The boost signal that would go to vent instead gets applied to the closing side of the actuator. There is no venting, there is merely PWM sharing of the boost signal between the opening side and the closing side, giving actual servo control of the valve position.

Ben C34 Grand Master

Ben C34

Posted
Posted
2 hours ago, GTSBoy said:

It works out like this. External gate can have a weak spring, or it can have a stiff spring.

When it has a stiff spring, it will want to close quite well, so it doesn't need any help. So you leave the 3rd port of the solenoid vented to atmosphere and you plumb the 2nd port on the solenoid to the side of the wastegate actuator that will make it open.

When you have a weak spring on the wastegate, you will probably need to help it close, which is what the connection diagram you posted does. The boost signal that would go to vent instead gets applied to the closing side of the actuator. There is no venting, there is merely PWM sharing of the boost signal between the opening side and the closing side, giving actual servo control of the valve position.

But there has to be venting for it to actually work as intended, which is why typically a 4 port will be used 

in that method of plumbing a 3 port above, you would initially hold gate closed with pressure to build boost, then apply pressure under dome to control / lower boost, but there is still pressure trapped on the top so you are screwed  .it won't exhaust anywhere because there is no exhaust port!

even if you didn't hold gate closed initially, once you put pressure under the diapraghm it will stay there when you swap to the top port, fighting you.

unless I am missing something here, which has been known to happen, it really needs to be a 4 (or 5) port valve to work

 

But really turbo smart do list other connection methods which are more typical. Would love to know if people have done it like above and what happened.

BK Grand Master

BK

Posted
Posted

Yes you're right Ben, that 3 port setup is a bit WTF. It does say for obtaining max boost for 3 port, so I can only assume you'd use this method with a 3 port solenoid and a weak gate spring, but I still don't like the look of that method. I wouldn't do it and can't say I've seen that before.

Common method for above would use a 4 port like this:

image.png.5dd4e32edff600e24cf0c05172178893.png

 

More common method for 3 port is like this, he should just do it this way. At least it will work properly.. (I've always used this method for single turbo / external gate)image.png.6b109fbdc540916b7cf6dc9328b08b76.png

 

 

  • Like 1
Ben C34 Grand Master

Ben C34

Posted
Posted
5 hours ago, GTSBoy said:

I think on the 3 port double connection they rely on cross talk between the two downstream ports of the solenoid to bleed excess pressure across from the NC outlet to the NO outlet (or vice, versa, which the hell way around it is).

True, but they will equalise pretty quickly then you can't do anything

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Shoota_77
      Car Rotisserie

      By Shoota_77 · Posted

      You guys need to live a little! Nothing keeps the blood flowing like lying under something that could collapse on you at any time! The vast majority of the weight of my car is out of it. There's zero attached outside of the interior of the car. It's pretty much full interior but once I take the front seats out it's just the dash and some of the boot contents remaining. I would guess that as it sits it would be already well under a tonne, even less without the seats. 
    • defari
      What Music Are You Listening To?

      By defari · Posted

    • defari
      What Music Are You Listening To?

      By defari · Posted

      https://www.youtube.com/watch?v=KyZDvZmvhik
    • GTSBoy
      Car Rotisserie

      By GTSBoy · Posted

      You'd be better off digging a pit and standing under it to shoot it.
    • MBS206
      Troubleshooting - motor wont turn over

      By MBS206 · Posted

      The easiest way would to be ignore the oscilloscope, grab a multimeter, and make sure all the main connections are right. An oscilloscope will give 99.9% of even technicians so much grief, as they have no idea what things should even look like on an oscilloscope. Which is also even more likely for someone who's first ever major work on a car is this If the battery volts are dropping down so low, the LDV will reboot the ECU, when it does so, it will drop out the start circuit. If this is occuring, the battery voltage should also come back up. Give it a few tests, even simple ones like when you're attempting to crank it, measure voltage from the engine block, to the negative terminal. You might find you've got really bad connections somewhere. My guess is the "new" motor has something like a shit starter motor, at which point, you can swap the starter motor from the old motor, to the new motor. Before I did any of the above though, I'd 100% confirm the battery in the vehicle. Most jumper packs are absolutely useless, especially if a battery has a bad cell for example. Also the new modern "jump packs" if you don't know what you're doing with them, you won't even get them into high current stage. So go back to basics, check the battery, especially with a known good one as a replacement test. Check ALL the wiring, this includes where they're bolted onto the battery, and bolted onto the starter motor. Check all the earth straps are on. Measure your resistances across your earth straps. A good check here is to measure voltage across the earth straps while you're trying to crank it. If you're seeing voltage, you've got high resistance joints! Oh, and once you've done the above, check the battery over again.
×
×
  • Create New...