
joshuaho96
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Everything posted by joshuaho96
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R33 GTR Rebuild + Upgrading
joshuaho96 replied to oSkylines's topic in R Series (R30, R31, R32, R33, R34)
I'm pretty confident I have the stock clutch in my R33. It is far and away the most forgiving clutch I've ever driven. The aggressive anti-stall + factory 950 rpm idle also makes it hilariously easy to get going even without throttle application in first. The slip zone feels a mile wide. The vacuum assisted clutch master also makes it feel lighter than something like an S2000. The factory idle control is probably not intended to be anti-stall or anything like that but it reacts to persistent low idle by ratcheting up the AAC duty cycle to max which gets you to like 1400-1500 rpm and even higher when the engine is cold and the cold start valve is still open. -
R33 GTR Rebuild + Upgrading
joshuaho96 replied to oSkylines's topic in R Series (R30, R31, R32, R33, R34)
NZEFI is in NZ, so it's 705 NZD. -
R33 GTR Rebuild + Upgrading
joshuaho96 replied to oSkylines's topic in R Series (R30, R31, R32, R33, R34)
Keep in mind the factory rail is 10.5mm, you need adapters like this: https://www.efisolutions.com.au/bosch-980cc-1100cc-fuel-injector-kit-x6-rb26-gtr-r or this: https://www.nzefi.com/product/nissan-rb-1000ccmin-top-feed-direct-fit-fuel-injector-kit/ -
R33 GTR Rebuild + Upgrading
joshuaho96 replied to oSkylines's topic in R Series (R30, R31, R32, R33, R34)
Don't buy those DW 1000cc injectors, they look like EV1s. Get the Bosch 040 980cc injectors instead, EV14s are readily available and dramatically better. You do not need an aftermarket fuel rail for the kind of power you're talking about, but if you intend on running a 400 lph pump at full speed without using something to slow it down then you will need a big FPR like the Aeromotive you listed. If you're doing the timing belt you should always do the water pump as well. Those two go together. Not as mandatory as it is on a BMW or Porsche where the pump will explode the second you get past 75k miles but you still don't want to play the odds. -
RB26 boost leak? limp mode?
joshuaho96 replied to Max32's topic in R Series (R30, R31, R32, R33, R34)
0.6 to 0.7 bar is still low if you've bypassed the solenoid and you're venting the wastegate vacuum line to atmosphere. Have you checked how much exhaust backpressure you have? -
The R33/R34 lost the valve on the heater core due to cost cutting. Their grand solution to this problem is to simply keep airflow from going through the heater core with the blend door. One thing I've noticed is that the cabin on the R33 feels like it warms up more than it should and I suspect the lack of a valve to keep the heater core from warming up the dash is probably part of it.
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R34 N/A vs turbo automatic gearbox
joshuaho96 replied to Batchy186's topic in R Series (R30, R31, R32, R33, R34)
Unless you're putting a wet clutch DCT or a ZF6HP or ZF8HP manual is the way to go. Automatics that don't have the lockup clutch running in all forward gears and modern shift logic are just really frustrating on something nominally meant to be high performance. -
Basically yes, if you disconnect the FPCM and ground pin 4 and 6 on the connector you have bypassed the factory FPCM. If the pump gets power from the fuel pump relay it will run full power immediately. You can see the same idea discussed for Z32s here: https://conceptzperformance.com/wiki/index.php/FPCU_Bypass_(2-Seater) If the pump isn't running then it's safe to say that something is wrong with the ECU. Initial key-on should cause it to beep as Duncan mentioned. Then it will shut off after an initial prime. I would also verify that this isn't a NATS issue or something.
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Open up the ECU. Verify that nothing is burned, no caps have dumped their dielectric or burst. To eliminate the FPCM to narrow down the ECU as the fault you can bridge pins 4 and 6 on the FPCM connector directly to ground. If bypassing the FPCM like this does not change the behavior then you know the ECU has failed. As for how someone could have damaged the ECU this way I don't really know. It is possible someone grounded something improperly and is putting way, way too much current through the ECU ground planes which can cause things to break. Not all ground points are equal, see this explainer to get an idea for what I'm talking about: https://www.haltech.com/news-events/ecu-grounding-the-dos-and-donts/
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For the RB26 ITB + turbo causes a lot of weird issues I think. Most of them are just ITB problems. At idle or low load IMAP is a very noisy signal because there's not that much vacuum volume. You can sidestep this with aggressive filtering or sampling based on crank angle but that makes it a slow signal. Then once you start using the throttle while I can clearly see vacuum during some part throttle cruise cases it easily saturates to atmospheric and spends a lot of time sitting around there for a solid half or more of the throttle travel until it spools the turbo. During cold start you also have to account for the fairly scattershot behavior of the cold start valve. The ECU doesn't even know of it's existence and it operates off of a very eyebrow-raising method of heating a bimetallic strip as soon as the fuel pump gets power to slowly close the shutter. It can get stuck open or start closing at a different rate with age so its relationship with actual engine warmup is loose to say the least. Then of course wastegate duty and all of that fun stuff affecting EPR also needs to be compensated for. My car has 4 cats on it from CA's emissions compliance requirements which has made a very, very noticeable effect on how much cylinder filling occurs despite running wastegate boost in both cases on an otherwise similar car. It used to hit the R&R corner of the map, now it actually doesn't exceed the factory intended load scale. I don't want to bother with tuning an engine twice in response to something as simple as a different exhaust. I've never tried EPR-based load to see what happens there but maybe in the future I might be able to muster the effort to evaluate it against the MAF load data to see if it helps tame the non-linearity problems. For now I plan on just using the factory MAFs and building a MAF load tune, then going from there. It's coming along well but the final 15% to make it drive like a factory car is taking 85% of the effort.
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New AFM or something more sinister?
joshuaho96 replied to Skaith4224's topic in R Series (R30, R31, R32, R33, R34)
You can try tapping the MAF or tugging on the plug while the car is stopped and see if it reproduces. Not unusual for MAFs to have failed solder joints when old. -
Looks like you want to check for power and ground on the CAS, then try seeing if there's continuity on the cam/home and crank signal wires from the CAS to the ECU harness. You can try also backprobing the ECU connector to see what kind of voltage those wires are delivering in the specified conditions in that table. Easiest way of course is an oscilloscope to read signal from those pins but not sure you can easily find one of those. You can also just use NDS while cranking to see if it reports RPM. If it does the ECU is getting some kind of signal. Oscilloscope will tell you how noisy it is.
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What is the actual code? These aren't OBD2 cars, they don't use OBD2 generic codes. If the starter is dead it won't crank. Most likely the code is that your ECU is losing the signal from the CAS altogether for whatever reason. The ECUs in these cars are pretty basic and don't do anything like cam correlation codes or any other plausibility checks.
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ECU tuning - difficult hot soak restarts?
joshuaho96 replied to joshuaho96's topic in General Automotive Discussion
I think he ran into similar issues, once it actually kicks over he experiences lean running for a little bit before it corrects. I suggested just papering over that problem with after start enrichment at high coolant temps but the whole thing is getting redone with a crank sensor because he's sick of fighting the distributor which was constantly misfiring at idle but weirdly not at cruise or full throttle. I'd see something like a full point of AFR lean-out in response to a misfire so I disabled all closed loop corrections even after I was done messing with VE tables. He's also using one of those old style AEM controllers that blasts the heater the second it gets power from the ignition switch so the sensors aren't going to last very long regardless and there's no real failure detection in those controllers either to my knowledge. Once he gets the new setup running I'm sure I'll have new and exciting issues to learn about. -
ECU tuning - difficult hot soak restarts?
joshuaho96 replied to joshuaho96's topic in General Automotive Discussion
Supposedly yes, but I have a theory that both are suspect. Haven't been able to get a pressure gauge on it to monitor what it's doing after shutdown as I got busy with other things since then but I suspect it would be interesting. This is a series 3 Jaguar E-type convertible. Prior to this it had Stromberg constant depression carbs which were absolutely horrific between that and the bizarre early 70s emissions vacuum retard distributor. I definitely agree that the conversion nature makes it hard to actually disambiguate what's going on but at the time of the hot soak we had come back from a fresh fill so the tank was full. The whole fuel system was just redone for the EFI conversion so I would be kind of surprised if it's leaking inside the tank but anything is possible. At the time of the tuning session it still ran the factory distributor, actually the ECU didn't have any engine position so there's no concept of anything like fuel injection timing or ignition sync. Verified the spark plugs were in fact firing too. -
ECU tuning - difficult hot soak restarts?
joshuaho96 posted a topic in General Automotive Discussion
Curious to know if anyone else has run into this issue before. I helped a friend tune an EFI conversion a little recently and an issue we ran into is that after getting coolant temp into the 90C range, after shutting the engine down and letting the whole engine bake for 5 minutes it wouldn't crank over anymore. Adjusting the cranking fuel pulse width did nothing. Surprisingly what solved it is setting a long fuel pump prime. He's running an MS2 or something like that so it wouldn't allow him to prime for longer than 3 seconds but keying on and off three times to get about 9 seconds of priming has reliably allowed it to restart now in this hot soak scenario. Anyone know a good explanation for exactly what's happening here? My working theory is that the fuel in the rail has boiled from heat soak and the pump needs to cool off the rail to have functional fuel injection again but I'm curious to know what others think. -
I can't really speak to modern cars, the calibration strategies are pretty opaque, probably because even the people cracking these things open don't seem to understand how any of it works. It seems viable, I just can't be bothered to take the risk at the moment trying to implement all of that on my end. The objection I have to alpha-N and blended strategies on things like Haltech and Link is that while it's nominally a simple thing to map it's a very brittle load sensing strategy that relies on too many assumptions to stay constant that I don't think will stay constant and requires a huge amount of additional compensations to function in an ITB turbo configuration like the RB26. It's not actually modeling mass flow through the throttle body or anything like that. Something as simple as AC/power steering/alternator generating more load at idle just isn't really accounted for without extra tables and has to be compensated for with all kinds of weirdness. The use of manifold pressure as the primary load scale for timing also just seems weird to me because it's non-linear with respect to actual cylinder air mass so at part throttle you basically have no resolution in your timing tables in many areas. My conception of a TMF model is that it should be able to overcome all of these concerns once set up correctly while not being hilariously slow and generally unreliable in transients like MAFs stuck to the very front of an incredibly long intake tract. I have no objection to speed density when applied appropriately either, I helped a friend tune a speed density setup on a Jaguar V12 recently and it works great when it isn't subjected to the weird idiosyncrasies of ITB turbos.
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Regarding closed loop fueling going all wonky with a misfire - I think that's an argument for better modeling and misfire detection in a standalone ECU no? Not sure anyone is going to ever bother with it but if we want standalones to potentially be viable replacements for things going into the CAN/GDI age the software complexity has to ramp up pretty dramatically to make it all work. I would consider most standalones to only be good enough for something like an RB26 that is stone age as far as a lot of the controls go. Sounds like you're describing throttle mass flow when it comes to MAF/speed density replacements. I'd be curious to know how many cars actually use it and how well it actually works, from what I've seen if the pressure ratio across the throttle body is too close to unity modeling the flow rate becomes a challenge. Whatever the E9x M3s use sounds rather brittle as well, supposedly something as simple as an alternator bearing causing excess drag at idle will cause all kinds of running issues. I would be curious to know if someone has actually solved the problem of ITB mass flow measurement without a MAF. I have seen what alpha-N or blended alpha-N/speed density strategies are like and I'm not really a fan.
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R34 GTR stock rear muffler insights
joshuaho96 replied to silencium's topic in R Series (R30, R31, R32, R33, R34)
Not sure there's any great pictures online, if you stick an inspection camera down the muffler you'll probably see it. -
The issue with retrofitting wideband on these cars is mostly related to control/where it's installed, way too many aftermarket controllers go full blast on the heater the moment the ignition +12V goes live, all kinds of weird calibration bugs, general firmware nightmares, etc. Haltech's recent woes with the NTK wideband comes to mind. Also questionable tuning/maintenance/build practices can all contribute to widebands that die seemingly every year or sooner. For these cars I would probably recommend running both just for the redundancy. At least you can probably trust that your wideband is working ok if the narrowband is cycling around stoich.
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R34 GTR stock rear muffler insights
joshuaho96 replied to silencium's topic in R Series (R30, R31, R32, R33, R34)
There is a spring-loaded flap that only runs it at high enough flow rates. Nissan did this to reduce noise at low load/RPM while reducing backpressure at higher flow rates.