joshuaho96

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.

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.

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.

Quite literally the first post said a modern ECU with engine protections. What engine protections do you think you can run without wideband, oil pressure, and fuel pressure?

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.

Yes, ECU pin 18 controls the fuel pump relay using the ground switch method. The two other pins that come from the ECU to the FPCM are signals to the FPCM to switch the resistor on the fuel pump to ground. No signal on the two means full power, one is idle and the other is cruise.

The LHD is aftermarket, there are no factory LHD R33s.

Yep, a rubber dead blow in an appropriate size is my go-to but those transmission fill plugs often have RTV and way too much torque applied to them.

Blue threadlocker + tightening by feel is probably the way to go then. You can feel fastener stretch. At first it will be relatively easy but usually you will hit a sudden increase in resistance. Once you get there don't go crazy with the force. A bit more is good enough.

https://www.nicoclub.com/service-manual?fsm=Sentra%2F2005%2Fem.pdf As far as I can tell there is no listed torque spec as it was not intended to be disassembled. It is probably either something like 7 ft-lbs or 12 ft-lbs. Assess what materials you're tightening into. If it's soft aluminum 5-7 ft-lbs is probably what you want.

When I check nicoclub for the 2005 Sentra factory service manual it mentions this step, so I would follow it.

This is another good video that focuses much more specifically on the locking pin.

The Haynes manual is basically telling you to retract the locking pin in the VVT cam phaser and then advance the sprocket all the way to the limit of travel and use a pin to hold it there. Why it tells you that I'm not sure. Go by the factory service manual instead for your car/engine. It's possible you have to do the same procedure but I have literally never heard of anything like this when timing a VVT engine. You can verify that the pin is not ruined by checking that it is straight, no visible gouging on the surface finish, and no cracks or anything like that. The pin is designed to basically work such that when oil pressure is removed from the cam phaser it will naturally retard and hit the lock position at which point the spring pushes the pin into the hardened lock pin seat. Cam phasing is adjusted from there by using a solenoid that controls how much oil pressure goes to each side of the cam phaser. You can see a breakdown of how it works on a Toyota version of the same idea here:

It will reduce noise substantially. When I got my car CA emissions compliant they added a bunch of cats and despite the Apexi catback and HKS front pipe it's quieter than a 100% stock exhaust. It also causes a hilarious amount of exhaust restriction because of how many they added but at least for now that means my turbos on wastegate boost no longer hit the R&R corner of the map.

Probably the average age of everyone here has moved up a decade too and people have re-learned the lessons of the 50s and 60s. Only takes a small group of people decatting their cars to have a significant impact on local air quality.

Nah full decats are obnoxious AF to everyone behind you in traffic. If it's not a track car you trailer to and from the track you should run a cat.

Does it do that when you're cruising at say 60-70 kph? At idle it will bounce between 20 and 80 for some time before finally getting too cold to read and going down to roughly 0 and staying there even when the engine is fully warmed up. O2 will start sluggishly responding around 30C coolant temp when you're driving around as well.

There's almost nothing in the ECU that is operating in closed loop fashion during cold start. Crack it open and see if you have any dead caps.

Rockauto has it listed for 60 USD: https://www.rockauto.com/en/moreinfo.php?pk=1644542&jsn=724

Check oil pressure yourself. Supposedly it can just be the solenoid failure and the gallery gaskets are actually fine.

I doubt any Skyline still running 10 years from now will actually matter for emissions.

The information asymmetry and resulting disasters I see is pretty bad out here.

Sell the car and buy something optimized for lightweight. You could replace all the body panels with dry carbon and only save maybe 140 kg while spending more on those body panels than the car itself. To actually reduce weight requires a complete rethink of the chassis, not window dressing. Look at how Lotus did it in their Elise and you have some idea of what it means to substantially reduce weight.

https://www.rockauto.com/en/moreinfo.php?pk=2656930&cc=1430921&pt=5416&jsn=886 https://www.rockauto.com/en/moreinfo.php?pk=2647470&cc=1429567&pt=5416&jsn=1004 Only difference is the A at the end. In the US the non-A version is listed for 2000-2003 Sentra and the A version is 2002-2006. I have a very hard time figuring out what the difference is just looking at the pictures at a glance. I have a hard time telling what head bolts can be trusted but TTY requires a new set every time. OEM in the US at least seems really cheap for head bolts, if it's only a few dollars each way I would just go OEM to not have to sweat it. Even then sometimes I just end up going OEM in cases like the RB26 oil pressure sensor where all the aftermarket alternatives are notorious for dying rapidly.