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Subaru Engine Swap/Updated to 4 Cam VVT


barge

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So I have a v10 STI PnP ECU that i seem to be rather quickly trying to make as un-PnP as possible.

I've got some CAN bus stuff I'm researching to clear up a lot of my digital IO and I'm wanting to figure out if there's any reason I couldn't run a newer STI motor with the 4 cam control provided i free up the necessary IO in the 1-4 range.

Obviously the wiring harness would require some work/modification to support this.

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Yes, should be do-able.  DI3 is AC request so you could move that to DI8 or 9.  DI4 is clutch switch so that is not really needed.

For the Auxes you cant use Aux 4 as that is needed for E-throttle but you can use Aux 5 for the 4th VVT solenoid.  Aux 3 is Tacho and Aux 5 is wastegate solenoid so you will have to move those somewhere else.  Possibly to Aux 7 & 8 if you dont need the tumble valves.

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  • 1 year later...

Bringing this back from the dead since I actually have a quad cam AVCS jdm motor in the car now and would like to get the exhaust AVCS connected and have a couple questions/clarifications.

The software will let me set Aux Output 7&8 as VVT solenoid. I'm assuming if it will let me make this selection then it will work OK on those outputs?

The power for the intake avcs solenoid is connected at the ECU. RH and LH each have their own +12v connection. Any comment on if i'll have an issue using this pin to supply power to the RH and LH exhaust solenoids?

The exhaust cam sensors are a 2-wire VR type. is there a preferred sensor ground source? Will i have an issue if i bring both sensor, sensor ground connections, back to where the crank sensor connects? If that's not a good idea any recommendation on pin selection?

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15 hours ago, barge said:

The software will let me set Aux Output 7&8 as VVT solenoid. I'm assuming if it will let me make this selection then it will work OK on those outputs?

I have never seem them used for VVT but if it lets you then it should work in theory.  Im more familiar with the wire-in ecus which only allow Aux 1-4 for VVT.  

 

15 hours ago, barge said:

The power for the intake avcs solenoid is connected at the ECU. RH and LH each have their own +12v connection. Any comment on if i'll have an issue using this pin to supply power to the RH and LH exhaust solenoids?

Measure the resistance to check.  I suspect they will only pull about 0.5A each.

 

15 hours ago, barge said:

The exhaust cam sensors are a 2-wire VR type. is there a preferred sensor ground source? Will i have an issue if i bring both sensor, sensor ground connections, back to where the crank sensor connects? If that's not a good idea any recommendation on pin selection?

What specific ecu/car do you have?

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7 hours ago, Adamw said:

I have never seem them used for VVT but if it lets you then it should work in theory.  Im more familiar with the wire-in ecus which only allow Aux 1-4 for VVT.  

 

Measure the resistance to check.  I suspect they will only pull about 0.5A each.

 

What specific ecu/car do you have?

If that tach output wasn't required for the DCCD I'd relocate everything to 1-4 but since it'll allow me to set then I'll give 7/8 a shot.

I will check resistance. I can't imagine they are much.

It's the usdm 04 Subaru STI PnP in a 2004 Forester XT. I've remapped and moved a lot of IO around.

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1 hour ago, Brad Burnett said:

on the exhaust cam sensors, i would tie the sensor ground and associated shield into the same ground that is utilized for the factory crank/cam sensors. but if that is not viable, the standard sensor ground should be sufficient. 

 

That was my plan so I'll proceed with that route. If i have issues I can always change it. The benefit of doing everything yourself.

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From my notes it looks like all cam and crank sensors were originally grounded to pin B22, the shields probably B31.

But any sensor ground will be fine.  You may have an empty sensor ground pin on A34, D1 or D2 as these pins where only used on certain models.  Other potentially spare sensor grounds would be A21, A26, D31 (oxy probes) & C31 (MAF).

 

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16 hours ago, Adamw said:

From my notes it looks like all cam and crank sensors were originally grounded to pin B22, the shields probably B31.

But any sensor ground will be fine.  You may have an empty sensor ground pin on A34, D1 or D2 as these pins where only used on certain models.  Other potentially spare sensor grounds would be A21, A26, D31 (oxy probes) & C31 (MAF).

 

Thank you for the clarification. The plan is to get all this installed and tested this Saturday. I'll follow-up here with results just in case someone else is trying to do the same.

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On 2/5/2020 at 3:34 PM, Adamw said:

From my notes it looks like all cam and crank sensors were originally grounded to pin B22, the shields probably B31.

But any sensor ground will be fine.  You may have an empty sensor ground pin on A34, D1 or D2 as these pins where only used on certain models.  Other potentially spare sensor grounds would be A21, A26, D31 (oxy probes) & C31 (MAF).

 

I've got the exhaust cam solenoids and sensors wired in and functioning. To get everything to the IO they needed to be I needed to relocate the boost solenoid and a "PS Pump" signal that I use to turn on my electric power steering pump.

In relation to those 2 relocations I moved them to ignition drive 5, 6.

Do i need a flywheeling diode on a boost solenoid if driven by an ignition output? If so, I believe it would be ideal to locate this at the solenoid connector, correct?

I have the ign6 set to be "ON" when below 500RPM (pulled to gnd) and "OFF" when over 500 RPM (which should pull up to 12v?). This doesn't look to be working like it did when connected to AuxOut8. I'm guessing that this either doesn't have a pullup or it's not strong enough. This is just an "engine running" signal that I'm using to start the electric PS Pump. Can I add a pullup to 12v? (recommended resistance?) or should I just put it through a relay?

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11 minutes ago, barge said:

Do i need a flywheeling diode on a boost solenoid if driven by an ignition output? If so, I believe it would be ideal to locate this at the solenoid connector, correct?

Boost solenoid will be ok without a flywheel assuming it is a common mac valve at 20-30Hz.

 

12 minutes ago, barge said:

I have the ign6 set to be "ON" when below 500RPM (pulled to gnd) and "OFF" when over 500 RPM (which should pull up to 12v?). This doesn't look to be working like it did when connected to AuxOut8. I'm guessing that this either doesn't have a pullup or it's not strong enough. This is just an "engine running" signal that I'm using to start the electric PS Pump. Can I add a pullup to 12v? (recommended resistance?) or should I just put it through a relay?

The ign drives are only pulled up to about 7V.  You can add a 12V pull up if needed.  Assuming the PS pump only needs a low current signal then 1-2Kohm will do it.

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27 minutes ago, Adamw said:

Boost solenoid will be ok without a flywheel assuming it is a common mac valve at 20-30Hz.

The ign drives are only pulled up to about 7V.  You can add a 12V pull up if needed.  Assuming the PS pump only needs a low current signal then 1-2Kohm will do it.

I am looking at trying out some higher frequency solenoids that'll do ~100Hz. I'll put a flywheel on that one when I install it.

Do the injectors drives have a pullup to 12v? I've got an open injector drive I can use as well.

Also... thanks for all the help. This forum really has been the biggest plus/selling point for Link.

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