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Long-term testing with Power FC single turbo boost control

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Long-term testing with Power FC single turbo boost control

Old 04-27-16, 03:18 PM
  #76  
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It's noted above that this is being operated by the "pre-control"... but in Mazda-speak, there are four entries on the commander:

[PAC] Port Air Control
[CCN] Charge Air Control
[TCN] Turbo Control
[PRC] Pressure Regulator Control

Is it one of these?

I checked last night, and it doesn't energize the solenoid with just the key on—you'll at very least need to start it.
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Old 04-29-16, 11:06 AM
  #77  
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Let me clarify a few things.

If you select "Sequential Turbo Control" box as unchecked, boost is controlled through the Precontrol output. This is the parameter "Advanced PC" . It can only be read by the Datalogit. The value is linear 0-255, with 255 being 100% duty.

If that precontrol wire has been cut, you need to control through the "wastegate" output. In order for the wastegate output to work, you need to leave sequential turbo control on and change the turbo transition values, as mentioned in the first post of this thread:



The parameter to log is Advanced WG, and it is also logged through the datalogit only. Neither the PC or WG are a switch. Switches come through as 0 or 1 bits in the Datalogit, and are viewable on the commander under the etc--> sensor/sw check.

The precontrol and wastegate outputs are fixed frequency, duty controlled (pulsewidth modulation). They rapidly cycle a pneumatic solenoid, whether it is the stock one or the BorgWarner one. The duty cycle is the ratio of ON time to OFF time, with a higher number corresponding to more ON time. The design of the solenoid and the plumbing affect what actually happens with higher duty cycle. You need to look at the duty cycle and boost (PIM) curves in order to understand what's going on.


[PAC] Port Air Control
[CCN] Charge Air Control
[TCN] Turbo Control
[PRC] Pressure Regulator Control
Port air control is in the ACV for control of secondary air injection. Port air corresponds to the airpump injecting air into the exhaust ports in order to stabilize combustion, lean out the engine-out mixture, and reduce misfire.

Charge air control is in the compressor Y pipe for sequential turbo control. Turbo control is in the exhaust manifold, also for sequential turbo control. Those two values are always inverted (they are never on at the same time; same as stock ECU). They are set according to the turbo transition high and low map. Pressure regulator control is the hot start solenoid, to raise fuel rail pressure when fuel temps are high enough.

Last edited by arghx; 04-29-16 at 11:09 AM.
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Old 04-29-16, 11:20 AM
  #78  
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OK, so bottom line, this can't be done with the Commander, you have to have a Datalogit?
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Old 04-29-16, 01:39 PM
  #79  
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if you are plugging it into the precontrol, you could mess around with the commander and MAYBE tune it just by guess and check. To do it in any kind of methodical way you want to look at the duty cycle curve.

If you have access to a Datalogit and can post some datalogs I can help analyze them.
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Old 07-12-16, 12:26 AM
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There is a lot of great info here, and it seems really straightforward, but I too am having some problems.

I have my boost solenoid connected to the wastegate connector. Its a MAC 3 port.
port 2= wastegate actuator (internal wastegate)
port 3= open
port 1= boost source

it seems like the WG% is going way up well before my setpoint is hit. my actual wastegate spring pressure is about 5psi.

Thanks for any insight you might have.

also it seems like maybe newer versions of FC edit use TPS voltage instead of percent.
Attached Thumbnails Long-term testing with Power FC single turbo boost control-screen-shot-2016-07-11-10.18.26-pm.png   Long-term testing with Power FC single turbo boost control-screen-shot-2016-07-11-10.21.11-pm.png  
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Old 07-12-16, 11:54 AM
  #81  
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The blue line is PIM (manifold pressure). Around 122 seconds, notice how the line rises but then flattens out while the green line (wastegate duty) is still at max? That means the ECU is commanding a closed wastegate with max duty cycle (trying to bleed all the air out), but the gate is opening anyway.


Pull up this old thread https://www.rx7club.com/3rd-generati...tegies-874031/ and you will see this diagram:



Try adjusting your plumbing according to the diagram.
Attached Thumbnails Long-term testing with Power FC single turbo boost control-boost_control.png  
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Old 08-02-16, 09:18 AM
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that was totally the problem, thanks.
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