discopotato03

From memory 0.41 at idle and 4 . something at WOT , I think I posted that above . I'll see if I can find Garys ear thisafternoon . Interesting about the closed loop idle timing . I was reading that feller from Celica.orgs thread on Tuning Datalogit but sadly the Toyota Datalogit software has different options to the Skyline ones . They can turn off this idle timing control and if I could do that it would give the game away for certain . It sounds logical that my TPS needs "advancing" up half a volt so the PFC can see the TP changes . Judging by the voltages on Datalogit I would have thought it would because the bad point is at around 0.43 volts (up from 0.41) but if its too low for the box to recognise then it probably thinks its trying to idle at 11-1200 revs and retards to pull it back . If I have it right the Datalogit guide mentions the scope for timing triming is 5 degrees either way so how mine turns 15 into 0 at times is anyones guess . Anyway fingers crossed this works and like the coils is another unforseen prob this car could have had for some time . A .

Fair enough I missed that point . Can I trust the Datalogits TPS voltage number at idle and adjust from there or do I have to probe the TPS plug wiring ? If probing the TPS plug wiring which is the sensor one and earth ? Thanks again , cheers Adrian .

I would have thought 278 was high for a GTRs but anyway . Nismo thermostat ? Possible cool running not helping . 3" into 4" exhaust , big pipes particularly if they increase down the system often allow reversions and cost low end torque , and consumption . Personal bias but I dislike split dumps because the gates tube is often too small and reintroduces at stupid angles . My experience with button clutches in road cars is the need to rev them to get them moving , consumption ? Your call but you may have overkilled in a few areas . Please tell me your static CR is not a lowly 8-8.5 to 1 , cheers A .

I think the heat exchanger is there to warm and cool but I suspect it has a say in cold start and warm up exhaust emissions and that what probably drove Nissan to provide it . You'd think GTRs would have gotten oil radiators like Evos did but they got exchangers AFAIK too . Doubt the racers had exchangers . A .

My PFC is set not to run in closed loop so all the std probe does , when the Datalogits not connected , is plug the hole . I've been searching here and it seems occassionally people have TPS issues from guesses incorrect setting or failing units . I looked up the part number for an ECR33 S2 and I believe its a Jecs part - number A22-661 . On EBay they go for a little less than $100 and I need to check out if any of the local vendors stock them . I've seen TPS units bugger up in either their idle or WOT switches or the variable resistor and send things awry drivability wise . I probably should buy a new one and regard it as a wearing part , one thing less to screw up . I'll look for a test/reset DIY later . Cheers A .

Yes well at the risk of splitting hairs I think the whole idea of cold enrichment is to make up for cold pistons chambers and valves absorbing initially a lot of combustion heat wchich pulls down the combustion temps and combustion pressure . More fuel means in theory more heat and when the internals heat up they don't rob as much heat from the combustion process . I don't think the extra fuel is there to overcome cold oil drag unless the oil is a high viscosity dino oil and the outside temp is very cold . For the record I just changed to Rotella 4T which is a 5w40 and I get no starting issues with EFlex E70 and the Datalogig showing around 10 deg water temp . I just highly doubt coolant temps in the mid 70s indicate that an engine would need extra fuel . Yes and I was wondering about those who chose to run cooler than std thermostats because in cold thempratures their engines may not even get to 80c . A .

Because 50 is not cold and at that stage the chambers piston crowns and valves will be higher than this anyway . The issue is that the std thermostats to regulate in the mid upper 70s and the cold temp correction in the 50+ area is set it will add extra fuel tapering off to 80c . So once up to temp if the coolant drops below 80c ie to 77- 78 it will add some extra fuel for no usefull reason . The fix would have been to make the upper set point coolant temp wise more like 70 and even thats a bit high IMO . A .

This issue is weird because the TPS voltage climbs and falls reliably and always has the same min and max . The issue occurs intermittently at around 1150 -1230 revs and sometimes it retards backwards by four to five degrees ie 10 - 11 and the fast idle (via accelerator) gets a bit unstable . Nothing in my timing table is less than 15 and no correction factors should be doing anything at normal running coolant temps . Sometimes it drops back to zero and not surprisingly goes a bit haywire with no load 1200 revs and 0 degrees timing . I don't know if its related but the nock number fluctuates from 0-1 and occassionally 3 . It should not be knocking with Lambda ratios of 1.00-1.04 . I've never touched a TPS on an RB so if someone knows the test/set process or can link a DIY I'd appreciate it . Also how to get a PFC to relearn the new min max voltages PLZ . I really would like to solve these niggling issues before going near a dyno and having problems that aren't tuning ones . Thanks in advance , cheers Adrian . One last are these S2 R33 TPSs a problem and sometimes need replacing ? Guesses not cheap .

Hi all , I'm getting some strange timing retarding taking place at very small throttle openings . I stumbled upon this today when looking at the logging moniter page and comparing it to the ignition timing table . I suspect the TPS or its voltage output may be part of it . At closed throttle I think its voltage is about 0.041 and full throttle is around 4.1v . Hot idle shows 15 degrees but at very small openings ie 0.43 to 0.45v sometimes the timing goes backwards to 10 or 11 but can fluctuate back to 6 or at least once 0 and it starts to hunt . Once the TPS voltage gets above about 0.55 volts everything seems to work ok . Is this something Skylines do or is this some isolated issue ? Thanks for any help , cheers A .

Well I ended up setting the injector trims to 65 and the latency from 0.15 to 0.14 , and the injection vs water temp to zero at 50C . Overall it seemed to run smoother and have better transients though i had to richen up the very low speed areas to compensate for the water temp enrichment not being there in the 75-80C area . Many other areas went rich because of the trim number increase from 62.7 to 65 . There is one thing I've found that puzzles me because I have no answer for it . If I run a log and look at the monitor the ignition timing does not match what the ignition table says . I looked through the various ignition compensations tab and nothing I can see should be altering what the ignition table says .This is at high idle speeds set via the accelerator BTW and the TPS voltage increases when pushing the throttle . Also somehow the boost kit option was not ticked in my last few saves and I'm not sure why that was . I think I'm getting better consumption ATM but won't know for sure until the next full tank , and I won't fill it whill fuel prices are as high as they are ATM . I've never seen Eflex prices as high as they are in Sydney now . A .

Thanks for the 02 correction info , its logical though I wish there was a way to set the feedback target . Maybe the intention is not to let uses set it too lean and burn valve etc in certain light load ranges . It sounds like Paul cottoned onto something when staying in open loop and aiming for 14.7 at 110 km/h and going a little leaner ie 15-16:1 at 100-80 km/h . I guess he formed his own safe load (speed) based cruise AFR system . I will try entering zeros into the 50C water correction section and I may try retarding the water temp vs timing section because I think my engine could warm up faster too . From memory the default setings are -1 -3 and -5 and thinking about it my innitial cold running can be a bit snatchy which probaby means its a bit too advanced and rich when cold . Now to injector latency or "lag time" . Other systems I played with years ago like the SMC allowed you to set the end injection or injector closed timing in the 720 degree 4 stroke cycle . The apexi PFC doesn't give access with Datalogit anyway AFAIK so this must be why having the "right" lag number entered sets the correct/corrected injection timing . My issue is that I can't seem to get a consistant answer from searching online as to what a S2 R33 GTS25Ts setting should be for direct fit 740cc Nismo side feed injectors . The RB and SR people don't seem to agree that the latency should be 0.14 ms though it seems early SRS and RB25DETs both used the same standard 370cc side feed injector ? Status (Trent ?) mentioned that is critical to have this right and from my previous mucking around on the autronic SMC that rings true and I think this is because injection timing has an increasing affect at low revs ie from maybe 3000 down to idle . I suspected that it also affects accell injection and cold start enrichment timing which in turn affects drivability and consumption . Anyway mine is currently set to 0.15 and changing to 0.14 isn't much but I'll move it anyway . A .

I've just finished this thread as well and I'm going to check my injector settings because I think the trim was at 48 and should be 50 with 740's . I added 30% when I went to Eflex E70 . Couple of things I'd like to clear up . Firstly I noted that Paul33 said his car often didn't get to 80C running water temp and if you look at the water temp enrichment the second last and last parameters are 50 and 80C . I wonder if these PFCs extrapolate between the two and If you run at ~ 76c you would still get a small amount of water temp enrichment . Secondly both Mafia and Paul33 mention the 02 feedback correction setting in the bottom right hand side of tab 1 . I think the default is 1.047 and I'd like to know what this actually is - possibly Lambda ? If so you'd think 1.047L for petrol would be leaner than 14.7 to 1 . In post 290 I think Paul mentions he's around 0.94 but how does that equate to 16 to 1 AFR ? He mentions "guys that get poo economy are around 14.7" . I think I can sort of understand this target AFR and tweak the airflow voltage curve to suit business but thats beyond my capabilities and hopefully Scotty at Insight can do this sort of stuff easily enough . Thanks all , cheers Adrian . Edit : I checked my injector settings and they are 62.4 (original setting 48 x 1.3 for E70) and latency 0.15 . I suppose they really should be 65 (50 x 1.3) and 0.14 latency . Worth changing ?

Yes I believe direct injection done properly opens quite a few doors but it also adds cost and complexity over port fuel injection . You'd think an engine with compact combustion chambers , a higher static CR , smaller bores and a longer stroke than RB25/26 , would better suit high ethanol content fuels for road use . Mind you I pull up behind a whallop wagon at my local Eflex pump and they were gassing up with it too . I assume it was a V8 being a very fresh looking SS so is this a factory option or something special brewed up for the Fuzz ? A .

Probably beyond for most of us but I've read some claims that manufacturers can make engines that give as good or better consumption than ULP but they have to be designed specifically for high ethanol content fuel . My best guess , and thats all it is , is that injection timing needs to be different with high eth fuels because of the higher volumes and rates of evaporation - and how fast ethanol burs as a vapour . Years ago when I played with an Autronic SMC I mucked around with injection timing but without a dyno to maintain steady state loads it was very hit and miss . I can't remember if Datalogit gives you access to injection timing . A . Actually last night I was speaking to someone about ethanol content and it seems the Americans have a few lower ratois available at the pump , sort of in the E30-E50 range . I sometimes think its a pity we don't get something like E40 or E50 because they are supposed to have much of the benefit of E70-E85 but using less pump/injector and probably easier to tune for better mileage . I wonder what an acceptable trade off would be for an engine designed for ULP and used for road only .

Yes I learn't earlier to turn the feedback off and leave it that way . Is there a way to set the target Lambda number you want it to use ? I don't have any EGT test gear but I imagine it would be handy too . Also playing with an RB25 is a pain coil and plug wise with the crossover pipe above the cam and coil covers . Must be real easy wth 26's . A .

Hi all , does anyone know the resistance test figures for std RB twin cam coils . I 've just changed my 96 era RB25 coils for Splitfires and to look at the originals were fine . No cracks or tracks or crudded contacts and the boots are all good too . Obviously something internal has gone off and it would be handy to be able to test the std ones to see if any are worth keeping . Also might help others to determine if theirs are stuffed . The difference between good and ailing coils is obviously smooth running performance and fuel consumption . Cheers A .

I had time to do some tuning today whilst running around and the coils have made a big difference . I was able to add more fuel in a lot of areas and it has made drivability better everywhere and mostly the mixtures are near where I think they should be . I didn't get a chance to load it right up but at least it doesn't break down with a bit of load on it . I wonder how many RBs are running around with ailing original coils , I think mine were the cause of some degree of grief the whole time I've had this car . I need to redo my petrol maps so it drives acceptably if I had to use PULP again . Cheers A .

Splitfires went in this afternoon but only had time to drive round the block . Feels a bit smoother fingers crossed should get better mileage and not break down when loaded up . Thanks to Kudos for their promp service . A .

Yep a while back I think I started a thread on Bosch EV14 injectors and I may have linked pictures of old L Jet injectors gutted next to EV14s . They are designed to have quick reaction times and work at higher than typical L Jet pressures . A .

If memory serves me correctly in the late 80s era competition teams were finding that prolonged use off high speed and boost were causing lean outs which could damage pistons etc . I think it was Murray Coote that burnt a Familiar rally engine on some event that included long stages of full speed full load running . You would expect that everything could become heat soaked particularly in hot weather and a slow reacting temperature probe could make a difference . Its hard to imagine it doing much in a road car here driven at legal speeds . A .

I was going to say that I think it was Guilt Toy that hit the wall with 740 Nismos at around 360 Kw on his RB2530 burning E85 . I'm also using these but if I had my time over I'd have bought the ID 1000 version of the Bosch EV14s . Your calls but 2000cc injectors are huge like enough to empty your full tank in about 4 1/2 minutes (12 x 4.5 = 54L) . By my rough dirty calcs based on GTs results 1.25 x 360 = 450 so thats possibly where the ID 1000s would get you if your pump/s and everything else could keep up . A .

Tuning on hold ATM because I'm having ignition system probs . The plugs were removed today and found to be the NGK BKR 7 heat range ones with big gaps . They were closed up to 0.8mm which showed a slight improvement but the issue seems to be the coils . They look very clean all over but that doesn't mean squat . SKs std coils were stuffed and they looked the same as mine so I'm ordering some pretty blue ones later today . A .

Yes the first number is a cold pouring index not a viscosity number . Also the hot or running temp viscosity changes when the oil gets really hot with hard use , this is why oils like say a 10W60 stand up to high temps better than a 10W30 would . If you never get your engine oil really hot ie track work hot the 60 weight just adds a bit more drag at normal running temps . Its really no extra protection and costs a small amout of power and some extra fuel . Most serious oil people will tell you that viscosity choice should be based on the oil temps your engine runs because this has a large bearing (no pun intended) on the oil pressure you'll have . Sadly in recent years manufacturers are going with lower oil viscosities partly because clearances are smaller but generally because less oil sheer drag means better fuel consumption and possibly cold start emissions dramas . Throw in "extended oil drain periods" as the yanks call it and it adds up to limited engine life IMO in a throw away world . Most of your average snot boxes are considered used up at 100, 000 Km and thin green oil doesn't help them in te long run . BTW do some research into ZDDP or Zinc Di Alkyl Dithio Phosphate because this is the good stuff used in older spec oils that protects high point load bearing areas like turbos and valve train components . RBs have direct cam lobe on bucket valve trains where "Green" engines are growing things like roller rockers and or roller tips so these engines don't die with these late eco cat friendly oils . Some of the best oil info comes from pushrod V8 sites because these engines with big cams and very high poundage valve springs to control big heavy valves need really good oils to stand up to the high point loadings - and green oils kill them . Have another look at the Mobil 1 synthetic sport bike oils because these are higher in ZDDP etc because sport bikes are more like F1 engines compared to car engines even good ones . High revs uneven heat loadings hard worked valve trains . GL Lubricants sell Mobil 1 Racing 4T in 10W 40 which is about righ for a street RB , its road oil BTW not competition regardless of what the name suggests . Porsche used to specify it for some of their turbocharget road cars and HRT were using it (10W50 version) in the pre E85 era , not sure what they use nowdays . A .

I believe on paper a Neo RB25/S2 Stag 25 ? puts out 206 kw and an R32 26 on paper 209 . Neo 25 is probably a cheaper simpler better all round road engine with a lot less complications/agro . Stag 25 block is like a 26 round the sump and possily has a better ratio diff for the larger (than RB20) engine . Your call , late Stag 25 better option IMO .

Also bought a set of std 0.8mm gap NGK BCPR6ES plugs which I thought were hard to find , Gardners said they usually stock them . I got them to look up the std replacement which was a 6 heat range Platinum 1.1mm gap type . A .