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Hey guys just wired in a 25 into my r31 the car runs and starts fine but am having trouble understanding how to wire up the vct/o2 my understanding is they are powered off the same wire, I’ve read elsewhere that one wire for the vct goes to ign 12v and the other to ecu pin113, hoping some can shed some light for me as there are only 2 conversion guides I can find but one is just a alteration of the other and isn’t any clearer to me, cheers

So installed xspurt 1000cc top feeds with top feed rail from scotty, Hypergear ss2, int gated, Haltech platinum pro, return flow cooler Now when I had it tuned it made 281rwkw @17psi but full boost was somewhere at 5400 when I mentioned that it should on sooner the tuner had said there was something odd with the VCT when he was trying to set it, he thought it could have been a timing issue, so I had him check that(it was all fine) he then later contacted me and said it was the wastegate not set correctly, set it and then sorted the mid range, boost at 4400. Now everything I've seen about the ss2 can have full boost at around 3800rpm, so it now has me wondering if there could actually be an issue with the VCT itself.(if VCT can help boost come on) So have been searching on here about VCT and looks possible that my VCT is stuck as its giving me good top end but possibly poor low.... I disconnected the VCT and drove it and it feels the same, but I am unsure if it feels the same because it was faulty before hand and has been tuned around it... The plug itself needs replacing as it doesn't clip on, I used a multimeter at the plug, car on, positive on one pin and neg on chassis and then other pin and chassis and no change at multimeter. Did it hot and cold if that makes a diff. Have I done it right? I assumed the positive wire was constantly on and neg switches on/off , so at least one of the pins would be giving me voltage. I have to take the car back at some point to sort something else out but just want to see if there is anything I can do to ensure its working or not.

VCT Problem Hi guys, I have an issue with power loss at 5.5k rpm onwards, after much troubleshooting im quite certain fault lies at the vct. I disconnected the plug, went for a drive and no changes. Same power at low end...and same power loss at high. I removed solenoid to see if actuator is working and it is. ticks and closes when fed direct 12v. Power fc is sending the signal. So its not the ecu. Now when i put the solenoid back into the head. wired direct 12v into it... it ticks and can feel the actuator moving(vibrates) however no change in idle whatsoever. From what i understand there was suppose to be a noticeable change in idle when the actuator closes. nothing happens. Would this point to the vct cam pulley mechanism being stuck/jammed?

Hi Folks. Wondering if anyone has heard anything like this before. Head is a RB25DETNeo and this tapping happens just for a minute or two after starting Hot OR Cold. There are no unusual sounds otherwise. It sounds to me that it's similar to a SR20DET VCT rattle, however while this sounds like it is in the same area, it happens if the VCT solenoid is unplugged. I don't know if this will actually affect things, if the issue is internally mechanical and not solenoid. There's not a lot of info on VCT rattle on RB25DET's. I have blocked off one oil feed to the head to combat blowby in the past. Note: This happens at about ~1500-2000 rpm. It will rattle once, or twice, and the car can rev past it fine. I.e, if you revved to 4k you may hear 1-2 taps while it revs through, but it always appears at that range. Note: If you rev the car slowly through the rev range after starting, this does not happen. You don't need a ton of throttle, but if you stab it or stand on it it'll happen, it will not happen if you say hold throttle at 10% and slowly rev through the range. The sound appears to be coming from the intake cam, from what seems to be just under the throttle body. Again, hot or cold, doesn't matter. Will hear it for about a minute of driving and it'll fade away pretty quick. Leaving the car idling does help if you leave it idle for ~2 minutes etc. No weird sounds under load at all. Car otherwise drives fine. From what I can tell, if you leave the car sitting for maybe 5? minutes, the sound will return on re-start. A little less than it would if the car is left overnight, but not much. Could be related (maybe not) but VCT has only just actually been switched on/wired in recently. Could be piston slap. Could be wrong oil, (5-40, was 10-60 in the past) could be something else entirely. Sound does not appear to be getting any worse since I noticed it (couple of weeks). May have always been there, because the car was previously auto and any throttle will go well over 3k RPM where there's no sound and no load. Any hints as to what this could actually be given the above info? Looking to know where to begin, or whether to begin at all if this is actually a common thing people don't talk about.

Hey all, First up YES I have searched the forums and google thoroughly and have not found a conclusive answer to my question, secondly please don't come on here asking - 'Why are you deleting VCT? It's better for low-mid range blah blah' because I'm upgrading to cams that are not compatible for VCT for a higher powered build. Currently building up my R33 RB25DET to support (aiming towards) 300-350rwkw on Pump 98. I know that is a huge variation in a power figure but I am not banking on a specific number, the engine/mods are being build to support that power but as to how safe the end result is is ultimately up to the tune/tuners. The head is away getting ported/polished/dedagged etc... and I am buying a set of Camtech cams - specs as follow: IN/EX 272deg IN/EX 9mm Lift No vvt/vct on inlet My question is. With the head off, is there any additional welding/filling up of oil galleries in the head in order to delete the VVT/VCT? Or is it just as simple as removing/blocking up the existing sensor? I don't particularly want to have the sensor hanging out the side of the head when it's not in use as I was hoping to just screw in a threaded bung. I have the two adjustable cam gears ready to go and the aftermarket ECU is a Link G4.

Just trying to source the cause of some knocking noise, seems to be comming from the VCT gear/ solnoid area. I checked the engine timing and all is good ( close as the marks can be 3025) but the intake cam gear itself has movement in and out . So i was checking the bolt for tightness and it seems to move the cam left or right a short amount independent of the gear.. Just need to if the above movement are normal and possibly supposed to move because of the VCT mechanism as i dont know how it physically works.

Cam dial in Hey all, bit of a brains trust question here. I have kelford cams that I have dialled in exactly to the specs I'm given, and my cold compression test is 170 psi. Was 145 with poncams. This extra pressure makes it impossible to tune. I have dialled them in to within 0.02mm of correct lift at 1mm degree point. At a loss as to why pressure is so crazy high. I'm thinking too much intake advance but it's perfect. Brainstorm please

RB25 lifters bleeding off cannot solve! Hi guys, iv got a brain teaser for you all. Firstly, overview. I have a built 25 in my 33 running tomei pump 2x 1.3mm restrictors etc etc. Ran 4 years problem free. many track days, lots of spirited driving and so on. Then I decided 22 pound wasnt enough so i put in 85lb supertech springs with TI retainers and camtech 272 9mm lift cams. (a 'drop in cam') From there on I instantly had troubles with lifters. originally dropping one or 2 in and out and in no time i was losing all lifter pressure and it sounds exactly like first start up on a new set of lifters. This is all however at high RPM. Anything under 3k is perfectly fine. but one big rev and I lose all pressure and it takes about 5-10 mins idling around to recover. And i guarantee its the lifters. Heres what iv done so far, bumped oil pressure from 65 to 85 pound. Zero change. Replaced all lifters with genuine low km ones i have spare. Zero change. Checked cam type with camtech, all good. checked spring heights, all good. Checked lifter doesn't go past the gallery. all good. Camtech have suggested its the vct bleeding off pressure, it cant be as its got its own feed. We have no idea what is going on. All ideas welcome! Anyone got a similar story or a fix?