Funky Boost Curve

[rob82]

  Blonk said:

  rob82 said:

  AdamXR6T said:

  rob82 said:

Elaborating I would say that's its going in and out of closed loop boost control, they probably have set the open/closed loop bounds large enough or not tuned the desired table correctly.

Who are you?

You must have something to do with the industry.

<{POST_SNAPBACK}>

I work as an engineering programmer at Chiptorque on the Gold Coast.

<{POST_SNAPBACK}>

Well Rob if you are an engineering programmer, then you would know the force that pulls on the diaphram / actuator open, is not called boost but vacuum and is not neccesarily 8 psi.

Actually negative 8 psi would not even go close to opening the wastegate.

Also the solenoid has no logic, it is open or closed, simple.

I have heard of several faulty wastegates / actuators ...

I had the problem on my T.....

Replacing the actuator or wastegate is a major job not a 5 minute fix either....

<{POST_SNAPBACK}>

I'm not quite sure you understood me. A manifold pressure reference whether it be vacumm or boost is applyed to the top side of the acuator. When the manifold pressure is greater than the wastegate cracking pressure(spring tension) the actuator opens and vents exhaust gases around the turbine in order to slow compressor speed hence reducing boost. Now if you bleed the signal to the actuator you will increase boost as it now take more boost to overcome the spring tension.

While the solenoid is essentially a dumb device the operation behind it is very complex. Determining the duty cycle on solenoid is performed using both closed loop and open loop control. While in closed loop the ecu applies a PI based feedback control loop. That is a proportional term and inegratal term. The proprtional term is based on the error from desired boost while the integral term is the change error of a defined time period.

If you want more detail I need to start drawing sketches. Sorry.

[Blonk]

Lost me......

3-12volts open solenoid

0 volts closed solenoid

I think we are saying the same thing anyway.... Robboxr6t needs to provide more information about what work was done.

[Robit28]

Lauchlan still feeding you guys

[rob82]

  Blonk said:

Lost me......

3-12volts open solenoid

0 volts closed solenoid

I think we are saying the same thing anyway.... Robboxr6t needs to provide more information about what work was done.

<{POST_SNAPBACK}>

Change you voltmeter to display Duty cycle and you will se what I mean. However you will need to see boost pressure before you can acutally measure DC. The operation of the solenoid is much like an injector however injectors meter fuel and boost control solenoids meter air.

And yes Lachlan still feeds us sh*t, we love it.

[Robit28]

hehe, at least it's good $hit

[xlr8ed]

Replace boost solinoid under the battery... Blonk is the expert on boost problems....

jeff

[robboxr6t]

  Blonk said:

Lost me......

3-12volts open solenoid

0 volts closed solenoid

I think we are saying the same thing anyway.... Robboxr6t needs to provide more information about what work was done.

<{POST_SNAPBACK}>

blonk what I have said is all that has been done/ told about by my tuner

[Eugene]

I remember see a few tunes with boost curves like this, it was from memory the software not the boost actuator, alot of guys were having "clicking solinoid" issues too, this all seemd to be conected, with the new software, I thought it was all over now?

Maybe a call/PM to Street tuner could clear up a few things.

witht he mods you have, and dyno dependant, you should see a comphy 270-280rwkw.

fuel pump, exhaust and cooler will be the next things to slow you down.

[2fardown]

I'm having the same problem with dynowog tune and another custom tune. It's really giving me the sh!ts.

What would happen if I was to fit an aftermarket electronic boost controller? Would this hold the boost more effectively?

Also you're complaing about only having 250rwkw but you're only running 8psi? Was that because it was pinging / detonating? Surely the tuner could have squizzed at least 10psi into it.

Edited 17/01/06 06:39 AM by AdamXR6T

[Eugene]

Re: After market boost controler.

I have played with these to, a manual GFB one does a good job, but gives you the same boost all the way through the range, set it and that's what you get everywhere.

the factory one does agood job, if its set up right, my car does go better with the aftermarket boost controler in, but it comes on too early and stays too long for my liking.

I think you can get electric / adjustable from the cab ones, but the factory system is fine, it needs to set up right, that's all.

Wog knows how to stop the boost solinoid clicking/fluctuating, I watched him do it.