joshuaho96

I haven't looked at weird things people have done to RBs before so I don't really know what to make of this. Looking at the vacuum line just above the oil filter it looks like it's looped back on itself. Checking the vacuum diagram I'm pretty sure both ends of the loop are supposed to go to the OEM boost solenoid. OEM boost solenoid is nowhere to be found but the harness connector is still present and doesn't appear to be modified, couldn't find any boost solenoid at all. Wouldn't this be equivalent to 100% duty cycle on an OEM solenoid without the restrictor? Thankfully this isn't my car.

Presumably the main concern is breathing under boost, so just reference how something like a nismo oil separator is plumbed up.

Can't you just use a dash tablet/double DIN head unit for this stuff? I feel like I've seen people doing exactly that for these cars with a standalone ECU.

If it didn't lean out catastrophically then it's probably an unrelated issue and you're fine.

I need to check precisely how this stuff is all set up again but I'm pretty sure that the throttle body port for the vacuum signal is a "weak" signal, at least in the RB26. I'm not sure exactly how it works but you absolutely cannot plug in an FPR vacuum line into it for example. So even if you're running 35 psi of boost in the manifold I'm pretty sure it doesn't just immediately pop the bottom cap off and shoot the contents towards your feet as if you shoved 150 psi into one of the ports.

The central locking looks like factory, the transponder is for a separate immobilizer.

If you're confident that you have proper compression/spark timing and it isn't your FPR you can pull the injectors and send them out for cleaning/testing.

I think we’re in agreement here. To me it’s more about reducing cost/risk. If you know you’ll never need more flow you can get the stock injectors with the factory binning. If you do need the extra flow though a good decapped EV14 is fine.

As far as injector choices go I recommend staying with unmodified injectors if you don't need the extra flow, usually high-flowing injectors is done by removing the diffuser plate which impacts atomization and spray pattern especially because these aren't air assisted injectors.

You can definitely make an adapter, I just don't know that anyone has one readily available.

The thread size is identical but as far as I can tell you will need a harness adapter. Keep in mind part of the reason why people relocate the IAT is that the stock position will heat soak so you will probably want an insulating washer on the IAT at least. Nissan deliberately put the IAT there because the goal of the original sensor was to detect heat soak and enrich the mixture in response. Also, the "retune" will just be changing the temperature vs voltage calibration table in the tune.

The shorter the wiring run the less resistance there is but you'd have to actually measure the voltage drop to be sure. If you've confirmed that the fuel pump is running at 100% flow all the time then your problem is almost certainly related to the regulator then. Every other part of the system is running like it would be at full throttle.

If you want the long explanation, you need a fast-reacting IAT because in alpha-N or speed density you want to be able to know roughly the temperature of the air in the cylinder the instant the intake valve closes. This feeds into the ideal gas law equation which is then used to estimate the air mass in grams in the cylinder. The reason why the stock ECU doesn't need to use a fast-reacting IAT is because air mass is not calculated but measured directly at the MAFs. So it doesn't matter what the IAT is downstream, you already know the air mass directly. This applies to any MAF-based system.

Pretty sure the base map is a weird one, one of the tables is TPS vs RPM only, another is MAP vs RPM only. I'd have to check to be sure but it's one of those things where even though a lot of bad things were done the holes in the system definitely maybe probably didn't all line up to cause a catastrophic failure. I would be nervous if this was a rotary engine though, those can die from a single knock event.

It's fine, main concern with a big pump is you overwhelm the pressure regulator but if you fit an aftermarket high flow one it shouldn't be a problem until you're really flowing a ton of fuel.

Could also be this. It's still a circuit, just a really simple one. The metal cup is technically an inductor.

I can still think of a number of weird things that can cause what you saw. It's basically just an inductor at the end of the day. RF interference might do it if nothing is wrong with the circuit. If something is wrong with the circuit flipping an inductor off and on with a smoothing capacitor connected to a load is basically a classic boost converter. The flipping of the inductor off and on to ground is usually supposed to be controlled by a transistor but in this case it could be literally anything. Tin whiskers, that kind of thing. Only way to verify is to get it on a bench and see if you can reproduce with known input signals.

Don't the R33 tachometers have a tendency to go completely crazy with age? Capacitors can lose their dielectric and basically turn themselves into a short circuit, dry joints intermittently making contact on inductive paths can pump up voltages beyond what's normal, etc. It's hard to say exactly what is causing it without really getting into the guts of it and reproducing/testing it but it's nothing beyond belief IMO.

It’s probably fine unless you actively tried to get it deep into boost and hold it just short of where it started misfiring. The danger is when you get deep into boost and it’s rich enough to ignite reliably but lean enough to get dangerously hot and knock-happy. If you just floored it and let it sit at the misfire limit you probably didn’t blow up your engine. The stock Haltech base map has even less timing than the stock ECU tune.

https://www.gtrusablog.com/2020/01/fuel-pump-control-module-fpcm-on-nissan.html It's a switched resistor on the ground that slows down the pump at idle. It's possible that this module isn't behaving and is a source of your fuel pump problems. You can check this by seeing fuel pump voltage at idle and seeing how it transitions. In the ECU map if your FPCM is still hooked up you should have a map for determining which of the 3 distinct fuel pump speeds should be commanded depending on fuel flow requirements.

I'm not an expert on fuel systems but a 0.2 bar drop in fuel pressure just from the return lines not flowing enough sounds like a lot, especially if you haven't bypassed the FPCM. Have you bypassed the FPCM btw?

I was just going by the book value mentioned earlier. Wouldn't this depend on the particular slope/response of the fuel pressure regulator? I figure the goal at idle is to drop fuel pressure so you stay deeper in the linear regime of the injectors.

Isn't there a delta in temperature across the turbine housing? Some of that heat has to go into generating KE for the turbine no? It's probably a second order effect compared to the delta in pressure so I doubt it'll be a huge benefit for performance but it's probably not entirely make believe.

Yeah I was hoping to learn more about the finer points of trying to make this pump fit some kind of R33 fuel pump hanger. Does the 6mm aux jet need to be used? Are the inlet/outlet vaguely in the right place? Stuff like that.

I want the car to survive extended track use but it's not the intended use, this is mostly just for fun on the street.