joshuaho96

The group A RB26 motors supposedly only ran max attack 700 hp in qualifying and dropped boost to get closer to 600 to actually survive the race. Those are engines that only have to survive one race before getting completely rebuilt. Nissan claims the Zexel group A R32 GT-R that did the 24 hours of Spa was running 550PS. So ballpark that's what the block was "designed" for. 540 horsepower or so for 24 hours of racing before rebuilding the whole thing, with everything around the block up to spec for 24 hours of endurance racing as well. Personally I don't want to blow up an RB considering the cost of parts these days so it's easier to just keep power goals conservative and focus on reliability/driveability but some people just want to make these engines go further so the parts are out there to make it happen. Big power builds may not last very long but they can work, if they didn't you wouldn't see 6/7 second RB powered GT-Rs.

A lot of modern cars won't even warm up if you idle them in many conditions, Honda's 1.5T is rather notorious for this.

If it's a street car you probably want poly bushes instead of the rose joint/spherical bushings. not sure if the R33s have the protection mode but you likely need to fool the HICAS system into thinking all is well in addition to locking out the HICAS so you don't get weird behavior in the power steering.

https://youtu.be/4d3nrBZjYKA?t=478 Splitfires were tested and seem to be all over the map there, but it's hard to say if the reason why the used RB25 coil was so bad was because it was old or not. Personally I've always been skeptical of going aftermarket for these kinds of parts, I bet the OEM coilpacks will end up comparable to a Splitfire in VQ applications.

I haven't been able to actually run the Haltech on a live engine yet so I don't really know if this makes any sense, but is there a more sensible way to do transient fueling instead of the enrich amount table being purely TPS-based? That seems like a very brittle solution compared to stuff like MAP prediction/X-Tau in Adaptronic's ECUs. Not sure if the non-linearity in the MAP signal correlates with actual non-linearity in transient fueling though, I get the impression the answer is maybe not. I saw that the axis selection allows for the enrich table to be MAF load vs TPS-derivative, I'm just not sure if that actually makes any sense. I learned recently that G&K is actually not a monopoly, the one other CA certified grey market emissions lab is J.K. Technologies in Baltimore, Maryland on the other side of the country. I have no idea why they're the only other one, but at some point in the past there was also NCDL which I believe worked with Canepa to get some 959s CA legal back in the day, but for whatever reason their certification lapsed and they can't do that work anymore. But yes, they're generally pretty unpleasant to work with and you need to be on guard with them. Document your car thoroughly before you drop it off, make sure the car is prepped as much as possible to reduce the time it spends there to the absolute minimum, document the car once you pick it up, etc. Personally I want to try and see if I can just send them the parts they need to modify for emissions compliance, then do the R&R with a mechanic of my choice to reduce risk further. The coating is actually a pretty thick film of thermoplastic urethane to try and prevent rock chips from destroying Garage Yoshida's work respraying the car. I suspect the adhesives and whatever they put on the TPU to keep it from yellowing is what's causing the smell. You may pass as-is, kind of hard to say at the moment. I would log the O2 voltage via consult and see if the engine is staying stoich where it matters, that will be a pretty important signal as to whether things will be ok or not.

The issue with changing the ECU map is if the tuner isn't 100% on top of things. You have to make sure everything is really optimized properly end to end. Cranking pulsewidth, cold + warm start enrichment, how rapidly you taper the initial cold start enrichment as the wall film builds and the engine no longer needs a comically rich AFR to idle stably, transient fuel control, all of it matters for the FTP-75 drive cycle. You can get away with just changing the fuel + ignition timing tables on the stock ECU for the most part and not have any issues on stock injectors + MAF, the problem is that most people and tuners don't just stop there. Changing injectors/MAFs on the Nissan ECU natively is a pretty big deal, it's not like a standalone ECU where everything is in real units like grams per cylinder or grams per second and you can just drop in a new MAF calibration curve with no other knock-on effects. It's likely that Nissan internally had that for their powertrain calibration engineers but to optimize for efficient use of memory/CPU cycles they simplify it down to something that doesn't allow for easy development. I know a guy who struggled with his Nistune map for a while, AFRs weren't really under control so it ran rich more often than not. Stuff like that will be an instant fail. Nistune has added some functions to make things easier these days but it's still not a simple table where you type in the flow rate data and the software does all the magic for you. I'm pretty confident that there's an issue on my end, reading out the consult port shows that the AAC is trying to drop the idle by going to 0% duty cycle but can't do it. If I slip the clutch it will start opening it up and can achieve 950 rpm if I don't cause too much chaos by adjusting the clutch pedal position/adding throttle. I'm still not actually at the point where my car is ready to be put on the dyno for testing. I'm also concerned about the paint protection film I applied potentially causing a failure of the evaporative emissions test, when I leave it in an enclosed garage I can smell the PPF when I walk in, it's a distinct acetone/nail polish smell. From what I've seen if you show up with any issues for G&K to resolve they're likely to hold on to your car for 6 months and then tell you to fix it yourself anyways when they find an issue blocking them from going further on the emissions testing, so it's better to make 100% sure there's absolutely nothing wrong with the car before you leave it with them.

I have the GTIII-SS working ok on the stock ECU map, just pull the wastegate solenoid plug to run wastegate boost for now. It's clearly hitting a kind of undesirable part of the ECU map though, I've seen 19 degrees of ignition timing at WOT. Doesn't seem to knock on 91 AKI CA gas though which is good. I'm just waiting on brake rotors because the rotors are pretty badly rotted on mine and the pads are very weak, they seem glazed or something because I can't even get the car to trigger ABS. Then I need to diagnose my slightly high idle (~1050 rpm with AAC at 0% DC) and send out the fuel injectors for refurbishing and to get them characterized properly. I've noticed that the engine doesn't feel 100% when driving it around at cold start so hopefully the fuel injector cleaning helps there. Feels like the engine has inconsistent power, almost like a weak misfire. It feels perfectly fine once it warms up though. Just turbos alone won't do anything for emissions btw, neither do adjustments to the high end of the fuel/ignition tables under boost. Basically only the areas with closed loop fuel control are tested. I've seen some pretty big fireballs on throttle closure from aftermarket tunes though and that's the kind of thing that will kill your catalytic converter and any hope of passing CA emissions.

I would be careful with the fuel for sure, 100 RON only on Mines' VX-ROM unless they've learned to be less aggressive with the ignition timing. Hopefully before the end of the year I'll have my car through CA emissions and I can start doing Haltech base map development in earnest.

Pretty sure the reason why it's not compatible is because the series 1 airbag has both the controller and the airbag in the wheel. The later series 2/3 wheels relocate the control unit. You would have to follow this conversion guide to do it right: https://www.gtr.co.uk/threads/r33-single-twin-airbag-conversion.8977/ Like I said, more effort than it's worth IMO. If you really want to do it you can, but I've made my peace with the steering wheel. One of those things where the more you look at it the less awful it becomes. At least they never put into production another prototype wheel which joined the bottom two spokes into one big spoke that looked especially awful. It's also worth mentioning, if you have the dual airbag setup it really complicates access to the evaporator box if you ever need to repair the HVAC door servo.

https://nissan.epc-data.com/skyline/bcnr33/3935-rb26dett/misc/D84/KD8400/ Survey says no, the Momo wheel only works with Skylines from 8/1996. I got over the series 1 wheel eventually but I grew up with cars that had those massive airbags. I figure it's probably less likely to fail than the newer airbags as well, seems like the 1st generation air bags in the 90s have been less likely to turn into anti-personnel mines with age.

Sounds like it may be a coolant temperature sensor issue then. Either a bad connection or a bad sensor. Verify that the temperature starts off at a sane value in Consult, then verify that it rises up to operating temperature in a reasonable timeframe while driving the car. If you see unpredictable jumps in temperature it could be a bad connection somewhere causing the problem.

Is it even possible to get down to 600 rpm in most cases without messing with the throttle stop? My R33 is idling around 1000 rpm right now even with the AAC duty cycle reporting 0-2 in consult under most conditions.

not particularly, but high idle is pretty irritating to drive around if it's bad enough.

it is possible, especially because you said the idle calms down when you disconnect the IACV. The torque converter has non-negligible drag even in neutral/park which is probably why base timing is advanced on the auto ECU. You may need to find some way to restrict airflow beyond what a dinky little idle screw can do. Possibly adjusting the closed throttle butterfly position, but that's a really big hammer for what could be a relatively small problem. I would only do that if you're 100% confident that everything else is correct and you're 100% confident that's the problem.

High idle shouldn't be caused by the ECU not seeing the transmission signal, but the fact that plugging in the AAC causes a major idle spike is a bad sign. At 1200 rpm is the AAC duty cycle 0-2%?

Are the ATS carbon clutches really all that good for street use? I was under the impression that the lack of springs in the clutch means it's much easier to cause shock loading of the drivetrain unless you take care to prevent it in how you drive.

Try an aerosol cavity wax like the one linked earlier, displacing water/oxygen will help to prevent the corrosion process.

Once you get logs of the issue feel free to upload it here, I can try and stare at it and see if anything stands out as well.

Should really be called the fast idle thermo valve, cold start air valve, or something similar that at least indicates that it's associated with cold start air regulation. My advice as I've been working through my own car is to get Nissan Datascan with a Consult cable and take logs when the car is misbehaving. You have to see what the ECU is seeing to understand why the engine is behaving the way it is. The ECU itself has very weak self-diagnostic capabilities, basically the only codes it throws are for things like open circuit/short circuit. All the sensor plausibility stuff is entirely on you to diagnose. How stable are AFRs when the engine stutters at idle? What does the MAF signal look like? Really meditate on the logs before you throw parts at the car. If you're suddenly losing consult cable connection during those drop-outs I would start suspecting the ECU or whatever is supplying power to the ECU.

Rear screen looks like it's one of the types with a metal hoop on the outside which causes it to stay up via tension against the headliner and the parcel shelf. Tint isn't a problem if you use a ceramic film but keep in mind that removing tint from the rear window especially is difficult and is what the mechanic was warning you about. Very easy to slice/rip up the rear defroster lines in the process of removing old tint, very difficult to repair such damage without replacing the glass. My solution has been to just keep the car garaged end to end but obviously in Japan this is a very challenging thing to do. In hindsight while the market seemed like it was crazy to you it clearly has only gotten more insane since you bought your car, so you were right to scramble for what you could while you could.

If they haven't tried to make things right despite giving them ample opportunity I would just post it here, no point in beating around the bush like this.

How well does a soft fuel cut work? Thinking about it in my head I can't imagine how you'd run on say 4 cylinders without causing a lot of weird vibrations.

If you're afraid of breaking oil pump gears there are some solutions that don't require pulling the engine. One is to use an ECU tune with proper soft limiting. The "best" method is DBW forcing the throttle to close, effectively idle control with the target RPM being just short of redline as long as the commanded torque from the APP is higher than the torque commanded by the rev limiter and engine RPM remains above the threshold for the soft limiter to kick in. I'm pretty confident this is actually the main rev limiting strategy used in a lot of cars these days, people complain that they can't bash the limiter in neutral anymore and instead the engine smoothly goes up to 3000 RPM and stays there perfectly. Another option is soft limiting by fuel or ignition. I have never tried a soft fuel cut, no idea how that would work without causing weird behavior like high engine vibration and wonky O2 readings from effectively a random misfire. Soft ignition cut can also help, but there is no free lunch there. You will cause EGTs to skyrocket this way, rely on this too much and it'll really do some damage. You really just want to take the edge off of the hard cut by smoothing the transition into and out of it to try and reduce the shock loading. You could also have high hysteresis on a hard fuel cut limiter. If you have to wait like 500-600 RPM before the ECU shuts off the rev limiter it'll be much harder to do a ton of damage compared to one that waits 50 rpm before going back to normal fuel/spark. This is probably very annoying though if you want to stay near the limiter for long periods.

I don't think dry sumps are inherently orthogonal to street cars, it's just that it seems to involve quite a lot headache if you want to keep the OEM power steering + AC compressor. I also wouldn't want oil lines running under the car all the way to the trunk and a big hot tank of engine oil sitting back there. My use case is going to be pretty much entirely street use, track use is secondary and the only goal there is to keep the car reliable and not scattering conrods to the wind, it doesn't really need to be quick so options like just running lower grip tires are on the table. I'm not a good enough driver to actually drive a car at 10/10ths without making the news anyways. I think there are front-mount oil tank solutions, it just involves something like deleting the washer reservoir and other similarly kind of unsavory compromises IMO. If I really wanted or needed a dry sump engine in a street car I'd probably just get one that has it from the factory.

It sounds like the solution goes something like sine or spline drive, upgraded oil pump, deep + baffled sump, maybe relieving the oil returns to improve the flow, a big external crankcase breather instead of trying to rely on the existing ones in the block, oil restrictor in the head, a lot of attention paid to the air/oil separation at the valve cover/before the compressor inlet, using the engine to help pull blowby out of the crankcase, and not trying to go full hero with semi-slick R compound tires. Also avoid blowby to begin with by using a torque plate, picking pistons/ring packs/etc that don't require loose clearances. If you want to go full race there are definitely dry sump kits out there. It's just a compromise, like anything in life.