RB20 ECU running an RB25 what to use as a VCT controller

Nistune topics related specifically to the 6303 cpu

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djstatic
 

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Re: RB20 ECU running an RB25 what to use as a VCT controller

Post by djstatic »

My switch is in the mail, what is the window to set?
1200
4700
djstatic
 

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Joined: Fri Apr 16, 2010 8:59 pm
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Re: RB20 ECU running an RB25 what to use as a VCT controller

Post by djstatic »

Here's the RB25DET pinout:
RB25DET_ECU_Pinouts.jpg
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My window switch (seems different to yours) just came in the mail so I'll make a DIY
http://www.summitracing.com/parts/SUM-830452-1/
SUM-830452-1.jpg
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Still not 100% sure what the window should be set too.. anyone?
Matt
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Re: RB20 ECU running an RB25 what to use as a VCT controller

Post by Matt »

On R33 the VTC cuts at 6100rpm and recovers at 5900rpm
djstatic
 

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Re: RB20 ECU running an RB25 what to use as a VCT controller

Post by djstatic »

Matt wrote:On R33 the VTC cuts at 6100rpm and recovers at 5900rpm
and when dose it kick in? just off idle right?
I'm not sure I can set a recover value. I need to check the documentation.

You should consider revising the FAQ (make it written for NFIers like me ;)):
http://nistune.com/faq-general.php#general10
More verbiage on VTC for RB20 ECU's. I would have bought a window switch 2 years ago (or the Z32 ECU)
Eric
 

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Re: RB20 ECU running an RB25 what to use as a VCT controller

Post by Eric »

in standard form it's activated off idle (based on rpm and/or idle-sw) and basically once the car starts moving (based on neutral sw and vsp-sensor).

If you can only set the window switch based on rpm, I wouldn't set it directly off idle, but probably at around 2000 rpm, as the engine may otherwise stall once you put load on the engine.
djstatic
 

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Re: RB20 ECU running an RB25 what to use as a VCT controller

Post by djstatic »

I went to install this on Sunday.. Very frustrating. what I believe to be Pin 59 has no volts (with the key in the start position, yes the battery is connected).

Can someone who has done this confirm my diagram please (or post a picture of how they hooked theirs up)?
djstatic
 

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Joined: Fri Apr 16, 2010 8:59 pm
Location: South East QLD, Gold Coast

Re: RB20 ECU running an RB25 what to use as a VCT controller

Post by djstatic »

OK.. instead of being cautious and triple checking everything. I decided to just wire the f'er and I think it's all good (Displays correct RPM, Blue light goes on after 1300RPM to tell me the window is active)

Settings are currently:
Low = 1300 (I may make this 2000 as suggested, once I go for a drive and see how i behaves)
High = 6000 (I won't be going anywhere near this until I can get to a Dyno)
Condition = NO (Normally Open)
Cylinders = 6CLY

I jammed a Multimeter in the end of what I assume is the VCT solenoid plug.
IMG_1734.JPG
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I get 7.2v when outside he window i.e idle and 13.5v in the window.
Is that normal? I was expecting almost 0v outside of the window.
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Re: RB20 ECU running an RB25 what to use as a VCT controller

Post by bachig24u »

whether it be RB25 or Rb20 ECU, 12v is on the solenoid or coming out of one of the pins on the solenoid plug when ignition reds are on. check this first.

the other pin is floating and needs to be earthed or grounded by the ECU or RPM switch to load the solenoid coil.

so basically the rpm switch is not sending 12v anywhere but infact earthing the terminal to ground (pin 113 from ECU does this).

if you earth the wrong pin, you will send the switching circuit in the ECU (RB25) to another place or blow a fuse if you are lucky.

I recommend that you cut the wire (from the loom) at the connector going to pin 113 of the ecu to prevent any damage to either RB25 or Rb20 ECU when installed.
using the engine wiring loom side of the cut wire, earth it, should hear a click, don't expect a massive change in idle speed or power if testing whilst driving as the difference is not easily noticed.

by the way, jamming MM in the plug won't give you a voltage that is accurate as one of the wires is floating and not earthed. Use a test light to confirm which terminal is power or simply connect the MM to Earth (chassis/battery) then probe the terminals to find the 12v constant when ignition is on.

tip, don't use 90 bends in fuel lines (it adds upto a metre in extra resistance on the pump for each bend).
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