discopotato03

Are they real Japanese ones or PRC ones ? I have a link to an American 240SX site that goes inside KA24DE distributor/optical CAS units . I would be very surprised if there wasn't some internal sensor pickups that were common to SR or KA ignition systems of the same era . Surely only the sensor and bearing are wearing parts and if we can find new ones it makes thousand dollar new assemblies unnecessary . . I tried searching Tridon for ignition bits and found nothing . A .

http://www.kudosmoto...ts4-p-1176.html This is from their site .

Does anyone have links to or part numbers for the sensors inside these Nissan RB CAS units ? The bearings look like late alternator ones so shouldn't be a prob . I think Kudos sell new CAS units complete but at $1000 plus is very exy . If I can get to Nissan in Rockdale I'll get them to price one , I expect much the same thing . My CAS is a Mitsubishi and its Nissan Pt no is 23731-02U11 which is the pre mid 97 R34 CAS type . Cheers A .

That type of Hall sensor distributor pickup was a popular Bosch distributor conversion back in the 70s and 80's . Things like Olden red motors and some Australian built Japanese cars with local content parts sometimes got them . For the record does anyone have pics of std RB25 and 26 puleys and are they all one piece so to speak - belt pulley wise ? A .

Personally I would rather try to use a new factory crank pulley damper and try to mount the toorhed wheel on the back of that . If one could be supplied set up and with a suitable Hall sensor and mounting bracket the install becomes straightforward . With the missing tooth wheels I think these are intended to be used with ignition only computers or with basic batch fire fuel injection . To run sequential EFI you need a reference signal driven off a camshaft (in the RBs case) because the complete four stroke cycle takes two crank revs and only one camshaft revolution . The computer needs to know slightly ahead of time when the crank (no 1 cylinder) is approaching top dead centre on the beginning of the first revolution of the two rev cycle . Somewhere there is a pic of the I assume exhaust cams nose with a wing on it for the hall sensor . If as mentioned above a sensor can be mounted under the belt cover that would be good too . If you could keep the standard CAS in position you would have a back up system or at least something workable while the crank trigger was being set up and tested . Looks standard though the average leg of ham probably wouldn't notice changes anyway . Cheers A .

Crank triggers get mentioned often with high performance and I gather most motorbike ignition systems so I though its time some info could be added here for those interested . The reason to consider crank triggers is that any ignition system driven by a distributor or camshaft will have slop or backlash to some degree and the only rock solid reference your ever going to get is from crank position - at the crank/pulley/flywheel . If you google crank triggers for RBs you generally go straight to Ross kits but at $2000 to buy and something like $1000 to fit they're not a cost effective solution for most of us . There's lots of other engines catered for like American V8s and a few popular Japanese fours but not so much Nissan RBs , shame they never had LHD Nissans with RBs in them ... In another thread here I posted a link to GTROK where some thinking individual mounted a toothed trigger wheel to the back of an OE RB (26 ?) crank pulley and if thats reasonably straightforward to do I'm stuffed if I know why every power hog isn't doing this . A crank trigger should be piss easy for most aftermarket engine management systems to read and the only other thing you need is a cam reference so you can time sequential fuel injection . I'll throw up some links that have interesting reading about the possibilities of fitting trigger wheel on pulley systems to Nissan RB engines . Without looking I know Nissan used a crank trigger for one year only (1981 USDM 280ZX Turbo L28ET) and Mitsubishi had them on some 4G63 turbo engines . I'm told BMW have used something in their flywheels and have a Hall sensor in their bellhousings to sense them . I chased a link to this site and it has a few interesting links and pics within , its a Datsun 1600/510 site BTW . http://www.the510rea...p?f=10&p=154506 I think if you can crank trigger a basic Nissan L Series engine you can do anything . The major differences pulley wise is of course the current multi v flat belt systems rather than the 70s era single v belts and pulleys . This is the GTROK link that shows pics of a trigger wheel mounted on a std RB crank pulley . http://www.gtr.co.uk/forum/161454-ati-crank-trigger-shells.html I'm not suggesting that everyone should spare no effort to have a crank triggered RB six but with a bit of thought and effort I don't think it would be a megga expensive thing to do . If anyone has any additional info on crank triggering an RB for reasonable money can they post it here please . Cheers Adrian .

GTROK link . http://www.gtr.co.uk...ger-shells.html I don't see anything like 3 grand in fitting this and a Hall sensor on an RB20/25/26/30 . If you can get the existing CAS to output a single sync pulse before no 1 TDC this is as difficult as it has to be . It would be brilliant if some enterprising business could organise a group buy kit that included a new factory crank pulley with the trigger gear mounted and balanced and the sensor plus mounting hardware . Throw in a laser cut CAS disc or instructions to modify the OE one and what would it owe us , would people pay a grand or so to basically achieve what Ross does for three times that ? Reckon I would . Cheers A .

My RB25 never quite sounded the same since its belt and tensioner change , I wish I'd known about this because I would have insisted on a genuine timing belt . I have a link I'll post from GTROK where someone mounted a crank trigger wheel reasonably cheaply on an RB crank pulley . A .

Yes I think the head or valve train anyway was loosely based on the Formula Pacific competition only L Series head . Personally I'd be wary of diesel based turbos for a two litre four banger , often they have big bulky housings and need external gates . A real GT3076R would be interesting on an FJ20 and is probably as compact as a nearky 300 Kw turbo gets to be , using a IW one should be straightforward on a DR30 exhaust manifold . A .

Yeah thats what I think yet the web and market is full of aftermarket CAS discs with a lot less slots in them . I did speak to Scott at Insight and he said get a nrw CAS if its more than a few years old . By CAS I'm not sure if he means the whole CAS assembly or just the internal electrical ring with the photo diodes in it . Then if this Vipec plug in can get good accuraye signals from it no problem . I just don't get why Nissan went with an ancient early 80s optic system when Hall triggers are so simple and cheap . Toothed wheel bolted to the back of the crank pulley and a hall sensor , another for the exhaust cam that requires little accuracyand Bobs yer uncle . Nissan actually had this system for one year (1981) in 280ZX Turbos with L28ETs only they had the cam reference hall sensor in the distributor , aside from a rotor button and cap thats all the dizzy had . Anyway waiting for Insight to open in the new year .

Surely the standard late 80s and 90s Nissan control boxes were not computing power houses . I keep reading that the CAS outputs a high frequency signal and thats what aftermarket computers have problems with . I also keep reading that belt/chain driven cam angle sensors have all sorts of ignition scatter problems and that makes it difficult to tune with good accuracy . Just for the record did the GMS GTRs run Electromotive computers and did they have crank triggers by any chance ? If so they though a lot of the factory cam driven CAS ... If there was a simple affordable way to attach a crank trigger wheel to the standard crank pulley that would be the way to go . You still need a cam reference so the brain can tell which of the two revolutions a four stroke sequentially injected engine is on but thats real simple anyway . A Cas disc with a single hole could do that . Or another Hall sensor and rotor . The big dollar builds should be all over this , cheers A .

FJ20ETs never had a twin scroll turbo standard , they used a small turbine series T3 in Nissan housings . Also the later DR30 RSXs had the higher compression pistons and the SMIC not the early ones . The later intercooled ones also had a slightly smaller 0.48 AR turbine housing in place of the earlier non intercooledand lower CR version 0.63 AR turbine housing . Also there were two versions of the DR30 FJ20ET inlet manifold , the later one tapered down faster towards the back reducing the plenum volume which you'd think may make them pick up a little sooner than the early ones . I think I still have a few of my old FJ manifolds in the cave including the rare Gazelle FJ turbo ones . My time with these engines was before Garrett sold integral waste gate T3 flanged GT30 turbine housings and in those days I always wanted a GT3076R/GT3037 but without the external waste gate . If I had my time over I'd have a manifold made to suit the Evo Tens turbo mounting flange because Garrett make a bolt on GT3076R turbo for the and its turbine housing is twin scroll with twin integral waste gates , you even get a choice of 0.73 or 0.94 AR . With the generic GT3076Rs compressor housing it could make an effective if pricey hot side for an FJ20ET . Lastly back to the CR business . FJs came from that ugly early 80's era where every know it all claimed you had to have a piss weak CR to avoid detonation with turbochargers . Most other engines of the day had pretty agricultural two valve combustion chambers and the manufacturers were too cheap to fit even small intercoolers ie Z18 Bluebirds 280ZX Turbos and even VL Turbos . The FJ20 was probably the first of Nissans production twin cam four valve heads with pent roof combustion chambers and these were a big leap ahead of any four or six pot L Series engine . Off the top of my head the early FJ ET made about 147 Kw and the later RSX intercooled one approx 194 . Both my FJs used the later higher (9ish) CR pistons and neither were really detonation prone . A .

So , can the Vipec read a brand new CAS as well as the OE computer ? I'm beginning to wonder why Nissan stayed with this optical cam driven CAS as long as thy have and not just reverted to a simple crank trigger . Why high reving RB26s didn't get them std is strange . A .

Your call , personally I thing "big cams" as in long duration ones are a bit pointless in an engine that doesn't rev and was intended to have a torquey low to mid range . Opening the valves earlier and closing them later tends to kill the cylinders trapping efficiency at low revs - robs your effective cylinder filling and creates all kinds of reversion issues . Long cams are designed to make an engine breath better at high reves where all the gasses are moving fast enough in the right direction . I suggest you start with a factory standard camshaft because you know it will work at normal revs and keep the valve train stable . Generally OE turbo cams don't have much overlap and IMO what does help is more lift rather than more duration . Heat wise you may find that Astrons are not very tolerant and for what Mitsy used them for that may not have been an issue . They did come from the carby era when power outputs were not very high for the capacity and emissions standards not so strict . ULEV engines have to be able to cope with running at higher temps and changes in design and material spec attempt to make them reliable . You have a choice here with the Sigma and Astron , try to develop it or go to a later car or even engine like say a 4G . Neither is going to be cheap to do properly and even if you got it right how is everything that makes a Sigma what it is/was going to cope . I've been there trying to modernise older cars and in the end its not worth it - to me anyway . I think if you want a RWD car better to buy something like a Silvia because all of its suspension and drive line systems are so far ahead of what 80s era Smegmas had . To a degree most Nissans are Mecano sets and better gear often bolts up / plugs in . Maybe better again an R32 GTST because at least you get a Skyline bolted onto your RB six .A .

Thats basically like working with early CAS type distributors ie FJ20 so only theres no rotor button or cap and the drive end is different . Do we know if the Vipec plug in has an issue with the std RB CAS disc because I thought they were a plug in deal . I did read that these computers were supposed to do everything in real time and when you consider that a CAS like a distributor is turning at half crank revs or 3600 at 7200 crank revs reading the photo diodes should not be that hard . Any fitters or dealers know the story , cheers A .

Back to basics . A big capacity long stroke four shouldn't need boost from nowhere revs because in theory the big cylinders should make good low rev part throttle torque . A 2.6L Astron is larger than an RB25 even though its head is pre historic by comparison and its more truck like bore stroke and rod wise . To my way of thinking if this engine comes on boost instantly and its using the smallest of the three optional sized turbine housings the answer is a larger housing . It seems to be tailing off before the engines out of revs which points the same way . Now to GT 30 UHP turbines . These are not small and actually flow quite well in appropriate sized turbine housings . Plenty of people make real good power out of GT30 turbines on RB25s but not so sure about with 0.63 AR turbine housings . Its probably a good idea to have a look at Garretts GT30 turbine maps to see how the gas flow increases using the larger 0.82 and 1.06 AR GT30 turbine housings . You can go to a larger GT35 turbine which with T3 flanges means a bored out GT30 turbine housing anyway but its pointless IMO unless you need the larger compressor wheel GT3582R turbos generally use . I think GT35 turbos are a waste on anything struggling to make less than 260 Kw and it builds in lag for no advantage . A .

Yep point taken but there are some good ideas in this thread . http://www.gtr.co.uk/forum/161454-ati-crank-trigger-shells.html If you were keen on a crank trigger wheel and could fit one to the back of a good std crank pulley thats 80% of the fight . A .

How hard is it to put a crank trigger system on an RB25 ? Cheers A .

Threw a quick dirty E25 brew together and with my best old E25 Dat files got it running reasonably quickly by setting the injector trims from 55 back to 51 . Should be 50 but had places to be and daughter disliked have lap top nursing duties . Will get it a little closer tomorrow if I get the chance but is easily good enough to get around . If I didn't know any better I'd say the ethanol is burning faster than the BP98 which I think is why the rich spikes are briefer and lesser so to speak . Numbers and bars on the Tech Edge display change faster with ethanol in the system . Cheers A .

Asked elsewhere and yes I searched first . If you want a fresh CAS can the sensors be replaced or do you have the replace the complete assembly . Mine is a 96 S2 GTS25T BTW . Cheers A .

Well on this one I searched but did not find . Scott said look at a new CAS but the only supplier I know of is Kudos and I don't think they have them for S2 RB25DETs , with the non Neo type CAS that is . I would have thought it cheaper to replace the bearing and circular plastic gadget Nissan CASs Ive seen in the past have but not sure if internals are available . If you want a fresh CAS or internals who sells them ? Cheers A .

I reset the TPS from 0.40 to 0.60v and with a steady hand I can get it to step up in 0.05 increments from 0.60 to 1v and beyond, from memory full throttle is something like 4.35v . If I can get Datalogit to show these repeatable TPS voltages then obviously power earth and signal must be ok with the tps . I think whatever ails this PFC must be internal because all the usual things seem to be alright . I agree that the symptoms are faulty TPS like but PFC via Datalogit shows otherwise . Its still doing the small throttle off ide retard thing and I noticed once that whilst driving at lowish revs and closed throttle the timing went to zero . One thing I noticed that did slightly help was throwing in a Jerry of Ultimate that I pumped out when first changing to Eflex E70 . It had some E70 in it because I put some in the tank to help flush the last of the petrol innitially . I can use a blend of E70 and petrol to lean out the bits I can't control with this ailing PFCbecause while I can make it richer antwhere I cant make it leaner at part throttle whilst maintaining drivability on petrol . When it comes out of closed throttle mode it wants to peg itself at around 0.92 0.93 Lambda until the throttle is open enough to make it use the fuel map - then its more like 0.96 to 0.98 Lambda as it should be . The idiot mode seems to be around the 0.52v TPS area and thats right about where steady state cruse throttle position is much of the time . Thinking back much of my experimentation with ethanol proved nothing because I didn't understand the true purpose of the PFC injector trim business and was treating that as a fuel trim not an injector size correction . I think I was getting better results with lower ethanol percentages mainly because I was bringing the injector trims back closer to where they should have been all along . Returning to straight petrol just proved that it can be too rich in an area that I can't lean out without problems . Anyway back to say E20 and live with that until the vipec Plug In is fitted and tuned . A .

I don't keep the logs for viewing because I see it live onthe monitor page . And yes this goes on standing still in neutral and playing with the throttle . I also see it live on the Tech Edges LCD display . I change gears and see a slight pause followed by a lightening fast lean spike . No amount of extra fuel table settings nor accel settings changes this . Its stupid , I back off and it goes rich on over run and stays that way untill I lift right off or open up again . Idle mixtures can be anywhere from 0.86 to 0.97 Lambda yet when logging the black box hovers over the same cells . People here say PFCs don't use either table at idle and use invisible settings they make up themselves after the learn process . The only other thing that may be problematic could be the CAS , Scott claims that after a few years they tend to go off and don't always output clean signals . I'm not sure if you can replace the plastic ring photo diode gadget or the whole unit but I'm going to do whichever anyway . Too late for me Paul , I have a Vipec Plug in on order because its more versatile and with a good tuner capable of a more refined result than I think a PFC can . No doubt either when working properly can get the same maximums but I suspect the PFC was intended to be on par with the std Nissan system while being tunable . I think the better current crop of computers can probably do it better than the std computer could with better than OE hardware . Anyway if I wanted to stay with the PFC I'd make sure the CAS was good , or new , because if its outputting BS then this would probably screw any computer up . A .

I don't keep the logs for viewing because I see it live onthe monitor page . And yes this goes on standing still in neutral and playing with the throttle . I also see it live on the Tech Edges LCD display . I change gears and see a slight pause followed by a lightening fast lean spike . No amount of extra fuel table settings nor accel settings changes this . Its stupid , I back off and it goes rich on over run and stays that way untill I lift right off or open up again . Idle mixtures can be anywhere from 0.86 to 0.97 Lambda yet when logging the black box hovers over the same cells . People here say PFCs don't use either table at idle and use invisible settings they make up themselves after the learn process . The only other thing that may be problematic could be the CAS , Scott claims that after a few years they tend to go off and don't always output clean signals . I'm not sure if you can replace the plastic ring photo diode gadget or the whole unit but I'm going to do whichever anyway . Too late for me Paul , I have a Vipec Plug in on order because its more versatile and with a good tuner capable of a more refined result than I think a PFC can . No doubt either when working properly can get the same maximums but I suspect the PFC was intended to be on par with the std Nissan system while being tunable . I think the better current crop of computers can probably do it better than the std computer could with better than OE hardware . Anyway if I wanted to stay with the PFC I'd make sure the CAS was good , or new , because if its outputting BS then this would probably screw any computer up . A .

According to Scott at Insight Skyline Plug Ins have had the six coil driver /V88 top board standard . Mine is on order and will be fitted and tuned in the new year . I was told that replacing the CAS if its a few years old is a good idea too so will have to chase one up soon , I think Kudos may sell new ones . Cheers A .