joshuaho96

I forgot which section of the forum I'm in. If you have a WC34 S2 with a JECS ECU then it can be remapped with Nistune. Load index maxing out at 88 is an RB26 thing, not RB25.

If you have a Nistune you can read the TP load index, if you're hitting 88 that means you've reached the limits of the stock map. Maybe you have a very high RPM/load misfire that is going to get worse but it could also be that you need a slight remap.

If the car is overboosting it will hit an R&R corner of the map. The calibration engineers set up the map so that as you exceed the load expected by the stock turbo the engine will run noticeably rich and pull ignition timing. I believe there is also protection if you exceed the airflow the MAFs can read.

https://www.gtr.co.uk/threads/n1-oil-pump.565753/#post-5759331 The N1 pump has the same flow rate as an RB26 OEM pump, the difference is basically in the gear dimensions and profile.

AFAIK in the RB26 section of the service manual it explicitly says not to take apart the AAC valve. If you took it apart once there's no harm in taking it apart again to see if you can save it.

Your oil pump has to have some amount of backlash in the gears, otherwise any little bit of a thermal expansion would probably cause the gears to bind and destroy the entire assembly. When you have a rapid transition from acceleration to deceleration like a hard fuel cut I'm pretty sure that the oil pump gears and the collar on the crank are not staying in perfect contact with each other, instead they're changing RPMs at subtly different rates. So the steady state load you'd predict from something like a pull to 7000 RPM is no longer valid, instead you have to consider the maximum relative acceleration and the resulting impulse from impact when that lash is taken up again. Some sources: http://www.skylife4ever.com/2011/01/real-problem-with-rb26-oil-pump.html

If this is a two wire knock sensor you should verify that there isn't a short to ground. Also make sure you don't have a marginal connection by tapping the wires while you test their continuity. If you have solid contact with the terminals the whole time but you see resistance changing as you move the wires around it's possible that there's a break in the line that is just staying connected part of the time.

If you choose to retain the stock AAC valve and want to buy a new one the cheapest source I found in the US was PartsForNissans: https://www.partsfornissans.com/p-jdm-nissan-r34-skyline-rb25det-neo-idle-air-control-valve-b3781aa500

Doesn't it logically make some sense that the factory low mount manifolds are going to spool faster than high mount? To generate pressure on the intake side requires backpressure on the exhaust side, the more exhaust volume you have to fill the slower that happens.

You don't even need to search for previous topics that talk about all of these questions, this has already been answered in this thread. The -9 is barely different from a -7. They will bolt on the same. As for response and power you can either look at the compressor maps already posted and other comments in this thread or use some google and find threads like this: Tuning ICE is not exactly for the faint of heart and RB motors are especially expensive to make mistakes on. Don't be penny wise pound foolish about this stuff. Again, you should think deeply about what you want from the engine before you start putting down the better part of 10k USD to modify it. What do you like about the engine/car as it is now? What do you want to change about it? What is important to you? What do you want to use the car for? If you can't answer those questions clearly you shouldn't change anything until you can.

Instead of just guessing you should unplug the solenoid connector and measure the voltages on all the pins with the ignition on. If you see the ATTESA controller engaging the pump solenoid and the pump is locking up the transfer case then there's no point in trying to replace the pump assembly, it's just doing what it's being told to do. I would be concerned that you have something in your car's harness that is injecting voltage to the pump solenoid even though the ATTESA controller is not commanding it. That would definitely throw a fault code as the controller can detect what appears to be either a short circuit or open circuit.

Personally I would do flex fuel these days not only for all the performance benefits but also as a futureproofing measure. Even if oil extraction stops for the most part as cars electrify the US will almost certainly have tons of ethanol, especially as cellulosic ethanol starts reaching mass production. E85 in my area is already substantially cheaper than the 91 AKI E10 that passes for "premium gas".

It's a very simple circuit, chase the wires. Shouldn't be seeing any battery power to the solenoid with the car off, the positive side is shut off by the ignition switch.

The way to test for hinge bushing wear is to open the door, then try lifting the door. If there is non-trivial free play you're going to experience issues like this. Usually it's the driver side door that has this issue though.

And if you’re going to bother with wiring a pump and relay you may as well do PWM fuel pump control. I wouldn’t bother with trying to source a good R32 ECU with Nistune for an R33/R34 with no type 6 boards available.

I have recently sent my OEM RB26 injectors out for service as a part of preparation for California emissions. Also as a part of that because I really don't want to waste perfectly good o-rings 6 months down the road I asked them to test the dead time and all that fun stuff. The spec for the stock injectors at 3 bar was something like 480 cc/min, I got 500 cc/min on average. The OEM ECU reports 0.77 ms dead time, their testing reported closer 0.5 ms. I asked them multiple times whether that made any sense, especially whether 4 bar having roughly similar but slightly lower dead time was normal for old injectors. Their answer was yes. I haven't started engine map development yet so I can't say whether their report was truly accurate but something to think about.

Definitely don't parts cannon your way out of this. As a part of the cam belt service the CAS has to come off. I would look very carefully at the CAS and the bits that it interfaces with to verify that nothing is worn or has play. If for whatever reason it was binding against the cam drive that could cause the symptoms you're seeing. If you're worried about plugs pull them and inspect them. It's not a modern car where pulling plugs is a massive ordeal so it's fine to put used plugs back in if there's nothing wrong with them.

Just use car wash soap on a cold engine, don't use a pressure washer. Don't use anything crazy like Superclean which is sodium hydroxide.

Regarding this picture: The leftmost hose barb is for boost control. The "water tube assembly" you're talking about has both vacuum lines and coolant pipes. That is the green line pictured on the vacuum diagram labeled as the boost source. The second from the left is the air feed for the cold start air valve, Nissan calls it an intake air regulator. That's a valve with a bimetallic strip in it that closes as it heats up. This piece is right under the intake manifold and is basically impossible to get to without pulling everything else off first. The rightmost is the AAC valve air feed as you have mentioned. The factory system is super basic bleed-style, when the solenoid opens it is bleeding the green boost source line to the rear turbo pre-compressor inlet, the wastegate actuator sees less boost as a result and doesn't open as far. As for how you should set up your MAC (presumably 3 port) solenoid, I would reference this article which details it pretty well: https://www.onpointdyno.com/boost-control-plumbing-get-it-right-save-money/ My entire intake side of the engine is still in pieces scattered across the garage so I can easily take photos of all this crap if need be, including how the lines should be and what they should look like. Keep in mind there are special orientations for a lot of these hoses, the manual likes to make mention of this multiple times.

I've never understood why people do this when there is a dedicated fitting on the back of the balance tube for the factory boost gauge.

I would recommend the DW440 brushless over that pump, they have an S14/S15 install kit so it's direct fit for the R33/R34s as well. If you're going to run new wiring and all this other stuff you may as well spend a little more on the pump and have something truly E85-proof. The brushed fuel pumps that are E85 compatible will still have a shorter lifespan on E85, brushless fuel pumps don't care at all. I am big on buy once cry once though.

8.5L is the system capacity, how close you will get to draining all of it depends on how far you go in draining the car. Coolant choice depends on what coolant you already have. If you have the Nissan green or blue then use that. If you have something else in the system then get the same. If you don't know what you have and don't want to take chances then flush the system with distilled water, then refill with whatever you want.

17042-RRR46 from Nismo, it's 1200 USD or so. Tomei USA (not to be confused with Tomei Japan) sells something that looks like the Nismo pump but is half the price: https://www.z1motorsports.com/fuel-pumps/tomei/tomei-r34-gtr-high-flow-fuel-pump-upgrade-276lh-p-10499.html If you want to run a DW300 my recommendation is to re-wire the fuel pump and to figure out a controller for it as well. Any little thing like high pressure drop across the fuel lines will mean that you're at the ragged edge of blowing the fuel pump fuse and you'll probably start burning marginal connections anyways. The Walbro GSS342 is another option, it is 255 lph and will drop as low as 190 lph at 70 psi but you have a lot of headroom left in your wiring as it only draws about 12A upper bound. You will be limited to pump gas only and you may run out of fuel pump if you try to run high base pressure and max out the turbos.

The brushed AEM 340 lph pumps are used all over the place. They might be fine Deatschwerks, Aeromotive, etc are all using that pump I think. Keep in mind the pressure relief spec on that pump is very low, only 80 psi supposedly. So if you have excessive restriction from the fuel lines there is not a lot of margin before it pops. DW's version of that pump has a 100 psi PRV. I also don't recommend buying off ebay for everything because of the markup and also questionable sourcing for a lot of parts. Keep in mind if you run a pump that can draw 15A you need to rethink your fuel pump wiring, the factory wiring is fused for 15A and realistically you shouldn't get too close to the limit because the wiring/electronics are not really designed for big power. The factory setup has a signal coming from the ECU to switch between different resistors for the fuel pump to reduce the operating voltage of the pump at idle and part throttle. This is done to reduce the power consumption of the fuel pump, allow for a lower flow fuel pressure regulator, allow the fuel level to get lower without the pump sucking air when driving around normally, and reduces how much heat you put into the fuel. You can get away without running a fuel pump controller but with the general availability of solid state high amp relays and the sheer number of digital PWM outputs on standalone ECUs it's really not that hard to do something similar to factory. I would not replicate the dropping resistor design of the factory controller, the dropping resistor has to dissipate quite a lot of power. Personally I think the DW 440 brushless pump is worth the extra expense/work/etc, mainly because brushless pumps can tolerate E85 much better than the traditional brushed pumps out there and they have much better high pressure characteristics, usually they go out to 125 psi for the PRV and they lose a lot less flow at higher output pressure. They also draw a lot less power for the same flow/pressure.

My R33 had standard turbos when the engine was pulled as a part of the chassis refresh. I didn't trust them though and never drove the car with them. The -7s are R34 N1 turbos, but R34 N1 turbo covers something like 3 distinct part numbers. The -7s I believe correspond to 14411-AA403. If you ask Nismo they believe that the -7 spec turbos have worse transient response if you're aiming for relatively low power, hence why they released the R3 turbo kit recently which is closer to the earlier AA401/AA402 turbos: https://www.nismo.co.jp/products/nismo_parts/NEW_PARTS/index_2021.html#a22 Their 450 PS claim includes a healthy derate from what the turbos are capable of pushed to the limit, it's also using an engine dyno: