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Rb25de Neo vct solenoid & cam gear an upgrade for Rb25det?

LaurelPWR
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Torques Mentor

Torques

Posted
Posted (edited)
On 5/10/2018 at 3:06 AM, Rusty Nuts said:

The solenoid is different and does not work in non neo engines, the vct is different too,  as GTS boy said they are specific to neo engines. Neo vct cuts in much earlier, from idle, and is active all revs to 5700rpm for turbo and 5400rpm for n/a wheras earlier RB25 ranges are 1050 - 5700 and 1050 - 5400 respectively

 

 

On the R34GTT the solenoid is activated via engine 'Load' which is called TP in the Nissan world.

It is not engaged via an RPM trigger. It is disengaged @ 5400rpm.

 

There's also a minimum temperature of 70C for the solenoid to work

 

Effectively 'd say VTC kicks in at around 3000 if you were to put the pedal to the metal.

 

 

 

 

R34.JPG

Edited by Torques
Rusty Nuts Experienced

Rusty Nuts

Posted
Posted
On 5/11/2018 at 10:44 AM, Rusty Nuts said:

I am quoting Tomei and a standard ECU there was no mention of Nistune in his enquiry. I am using Nistune in mine and using the start point at 1050rpm because the VCT internals lasts longer physically if its actuated when oil pressure is higher, they tend to "bounce" internally at idle

As I said mate i'm quoting Tomei and I put a test light on the vct output and it lit above 1050rpm. If there is 12volts there what other conclusion can I make??

Rusty Nuts Experienced

Rusty Nuts

Posted
Posted
13 hours ago, Torques said:

There's also a minimum temperature of 70C for the solenoid to work

I know you are in pommyland mate but how long do you think it takes to hit 70C over here in the land of Downunder.

We don't need those little engine heaters to keep our oil warm overnight like my old man used under his Sunbeam Alpine when we lived in Manchester.

Rusty Nuts Experienced

Rusty Nuts

Posted
Posted (edited)
14 hours ago, Torques said:

On the R34GTT the solenoid is activated via engine 'Load' which is called TP in the Nissan world.

Mine is a RB30/25det neo. In a R33 auto with Z32tt fully manualised auto running R32 Nistune so thanks for the chart but has nothing to do with my setup.

Edited by Rusty Nuts
Rusty Nuts Experienced

Rusty Nuts

Posted
Posted (edited)
14 hours ago, Torques said:

The solenoid is different and does not work in non neo engines, the vct is different too

And this was the subject as I recall. Not interested in a spitting competition either.

Edited by Rusty Nuts
GTSBoy Grand Master

GTSBoy

Posted
Posted
43 minutes ago, Rusty Nuts said:

And this was the subject as I recall. Not interested in a spitting competition either.

And yet, that's how it seems all of your above posts read.  Not a bad effort for a newbie to come in and take the mantle of prickiest poster, but there you go.

  • Like 2
Torques Mentor

Torques

Posted
Posted (edited)
4 hours ago, Rusty Nuts said:

And this was the subject as I recall. Not interested in a spitting competition either.

You completely lost me here maaaate :)

I merely stated what the OEM ECU does. 70C+, TP of 56, OFF @ 5400, and no fixed RPM for on

No competition intended!

Edited by Torques
Torques Mentor

Torques

Posted
Posted (edited)
4 hours ago, Rusty Nuts said:

Mine is a RB30/25det neo. In a R33 auto with Z32tt fully manualised auto running R32 Nistune so thanks for the chart but has nothing to do with my setup.

Mate the chart is from Nistune, and I replied to your statement about the OEM R34 GTT :)

I also do run the Z32TT ECU on NT .. so I think there is some overlap to your setup ...

 

 

Edited by Torques
Torques Mentor

Torques

Posted
Posted (edited)
On 5/10/2018 at 11:33 PM, Dose Pipe Sutututu said:

Regardless of NEO or non-NEO the RPM where it is enabled or disabled is 100% configurable if you're not using a PowerFC or Stock ECU.

The window where it stays on should be tuned till when torque starts to decay, of course this is all dependant on what parts have been bolted to the motor.

Generally for me, I will do one run with it turned off and one run with it turned on past max torque ie close to red line and overlay the derived torque graph. The intersection point is optimally where it is turned off. Also once off, the motor will happily take more timing

 

Yes, that's the best approach ... one run off, the other one constantly on.

Edited by Torques
Kinkstaah Grand Master

Kinkstaah

Posted
Posted

Has this ever been done as an example as to when to turn it on?


I had always heard it comes "on" at loads just above idle, i.e ~1200rpm with 'some' load. But above posts insinuate it actually can/should come on at about 3000rpm and off at 5400rpm?

Anyone done a dyno with it on/off between 1000rpm and 3000rpm?

  • 1 year later...
r32 gtst Newbie

r32 gtst

Posted
Posted

I have some info for you @LaurelPWR,

Rb25de Neo cam gear is 30degrees advance

Rb25det Neo cam gear is 20degrees advance

N/A cam gear is indicated by a green dot on the front face.

I now have my own question, has anyone ever had issues with vct cam gear seal leaking when externally feeding vct, eg supplying it too much oil.

Is it required to restrict Vct feed line with the neo system? Engine is Rb30/25 Neo.

Rusty Nuts Experienced

Rusty Nuts

Posted
Posted
1 hour ago, r32 gtst said:

I now have my own question, has anyone ever had issues with vct cam gear seal leaking when externally feeding vct, eg supplying it too much oil.

Is it required to restrict Vct feed line with the neo system? Engine is Rb30/25 Neo

No never had a problem with oil leaking, I installed new seals at build. I did not use any restriction either.

r32 gtst Newbie

r32 gtst

Posted
Posted

@GTSBoy im more worried that its flowing too much oil to drain back rather than pressure, may be pressurising the area behind the cam seal because it cant evacuate the oil quick enough and therefore pushing past my brand new seal, does anyone know the fluid path of the vct well to share their info?

GTSBoy Grand Master

GTSBoy

Posted
Posted

But what flow are we talking about here? This is not powered by flow. It is powered by static pressure. The oil doesn't have to go anywhere. There is probably a little flow channel somewhere to allow it to purge air out, but it is supposed to receive lots of oil pressure because it is oil pressure that pushes the actuator. It's not like a turbo where the oil just has to be there and any extra pressure will push it through the seals. Pressure is desirable here.

r32 gtst Newbie

r32 gtst

Posted
Posted

@GTSBoy im not entirely sure how the fluid dynamics work but i do know there are 4 vents around the gear that exit the gear, surely excess oil would have to go somewhere?

GTSBoy Grand Master

GTSBoy

Posted
Posted

You're still working on the assumption that there is such a thing as "excess oil". I would argue you want full engine oil pressure available in the actuator and that the flow away from there through the bleed holes is whatever that pressure will cause applied to that cross-sectional area.

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