joshuaho96

75W90 GL5 is fine. If you aren't sure about the type get one with LSD additive.

I have seen enough fire and brimstone from TSBs about roloc disks causing spun bearings that foreign object contamination is top of mind for me. For sufficiently large particles you might be right but usually it’s a distribution of debris and some of the larger particles can also break down and shed bits. If local shops report RTV contamination in a turbo is enough to wreck them I’m taking zero chances if I can help it.

It is fine. The bigger issue is people not being careful with their oil between breaking the seal and actually using it. I have seen literal pebbles of asphalt fall out of "clean oil" bottles. Always take great pains to avoid dropping the plastic foil bits into the oil. Try to avoid putting anything dirty into a "clean bottle" like vinyl hoses, etc. I pour my oil into a syringe, then cap it, then inject into the diff/transmission/etc instead of sucking it up with the hose now. I never drain "clean oil" from an engine and try to reuse it. List goes on. Don't care how clean it looks, the moment it goes into an engine even if it looks brand new I am not going to risk foreign debris getting into something.

I've worked around a crunchy/grindy gearbox for so long now that track instructors note how I have absolutely awful shifting habits. S L O W shifts and then blipping the throttle even on upshifts out of habit. My vote is R33 series 3 gearbox, those are still readily available and relatively cheap.

How fast are you doing the downshift? 4th gear was revised multiple times until 1998 to fix this issue. Synchro clips can fall out, synchros can wear. Most likely you're looking at a new transmission unfortunately. If you need to limp it until then double clutch downshifts into 4th.

Change the transmission fluid. I would try Motorcraft XT-M5-QS if you have it in your area for a reasonable price. Also, double check your clutch is fully disengaging. If you are not pushing the clutch pedal to the floor fully for every shift now is the time to start. Make sure the clutch is fully bled. The damper line requires two distinct bleed points to be purged of air or it will not disengage the clutch properly. If either hydraulic cylinders input or output are losing hydraulic pressure in their seals/leaking you can have problems like this. If you've ruled out everything else then the most likely explanation is the synchros are worn and you need to double clutch the shift or rebuild/replace the transmission. The transfer case is discontinued FYI so you may want to rebuild it while you're in there too. If the chain stretches past spec it can do a ton of damage.

Theoretically maybe, but if you capped it tightly it's fine.

Constant tension spring clamps need to be replaced if bent past a certain point. Once they turn to a certain age it's also an automatic replacement in my book. They get rusty and lose their tension. Also once hoses get to a certain age if you don't set the clamp exactly in the groove when disconnecting/reconnecting the hose it will almost certainly leak. As mentioned before you should also cap off the idle-up valve to make sure it's not sucking fluid or leaking air into the system. It's generally speaking less demotivating to figure out which change fixed your problem vs failing over and over until you locate the problem precisely.

You can try capping the power steering idle up valve at both ends if it's old. The valve and the intake manifold. That is something that is known to fail in Toyotas with age and it will suck power steering fluid into the intake and burn it in the engine which can cause issues. Then bleed it again with engine off first. Do like 30+ lock to lock turns with the front wheels off the ground.

Do you have any hose clamps that are not OEM? You must use constant tension clamps in the system or when it gets cold it can be a "vacuum leak" on the intake side of the pump. The other thing to think about is whether there is excessive restriction on the inlet side of the pump. If it's pulling too much vacuum the cavitation on the pump will generate air bubbles as well and also burn the fluid.

Maybe, but HKS' laughably expensive advanced heritage intake system (1.5M yen, listed by USA dealers at 15k USD) was sold out almost immediately and I'm not sure they ever re-opened orders for it. That's the kind of money that gets you a new block and head these days and people are spending it on benefits that boil down to "the twin turbos aren't quite as garbage as before".

Do not replace the power steering lines with this stuff. If it's anything like the Chase Bays stuff it will leak and be worse than stock. The reason why the reservoir is on the LH/passenger side of the car is because that's just where the reservoir was most convenient to fit. Don't overthink this stuff. The intake/cold side of the engine is pretty busy on these cars. And again, the hardpipe is designed to be a janky power steering cooler. In theory you can replace it with a real power steering cooler but that's really only for track use where boiling the fluid is a distinct possibility. Start with the low pressure lines feeding the pump from the reservoir. Make sure there isn't a bunch of junk in the reservoir filter. Be careful to not get ATF all over the engine bay. I hate dealing with ATF spills, you can clean it up and the slightest crevice will still release more oil that can still drip over time. You also want to inspect for leaks before you make a mess and can't tell what happened. Most likely you have a leak somewhere that is allowing fluid out and air in. Failing that it's allowing air in but not fluid out. Only place I can really see that happening is on the low pressure side because the pump will pull a slight vacuum to draw fluid in. Everything after the pump is high pressure or lower pressure, approaching atmospheric by the time it returns to the reservoir.

It's not, but it does feel like a bit of a missed opportunity regardless. For example, what if the cylinder head was redesigned to fit a GDI fuel system? It's worth like two full points of compression ratio when looking at modern GDI turbo vs PFI turbo. I'm pretty reliably surprised at how much less turbo it takes to make similar power out of a modern engine vs something like an RB26. Something with roughly the same dimensions as a -7 on an S55 is making absolutely silly power numbers compared to an RB26. I know there's a ton of power loss from things like high tension rings, high viscosity oil, clutch fan, AWD standby loss, etc but it's something like 700 whp in an F80 M3 vs 400 whp in an R33 GTR. The stock TF035HL4W turbos in an F80 M3 are really rather dinky little things and that's enough to get 400 whp at 18 psi. This just seems unwise no? I thought the general approach is if you aren't knock limited the MFB50 should be held constant through the RPM range. So more timing with RPM, but less timing with more cylinder filling. A VE-based table should accordingly inverse the VE curve of the engine.

The reservoir is pretty far from the pump, as others have said some of the pipe is also a rather janky power steering cooler. Find the leak. It might be the rack, might be a hose/pipe, etc.

Easy place to start is jack up the front end, turn steering wheel lock to lock and see if any air bubbles purge. If nothing happens it's probably time to pull the pump and inspect. It could also be a line is clogged for whatever reason and you need to isolate the part of the system that is blocked on the high pressure side causing the pump to be unhappy.

Is the RB26 actually that far off the mark? Honestly from where I'm sitting a VR38DETT is not actually that much more advanced than the RB26. Yes, there is a scavenge pump on the VR38, it's smarter in a number of ways but it's not actually jumping out to me as alien technology. Something like a B58 or V35A-FTS on the other hand has so many surprising little design features that add up to be something that just isn't comparable.

I thought an engine that needs more ignition timing to make power is going to result in less power due to reduced knock margin? More time for the combustion to propagate -> more time for it to heat up the rest of the mix to detonation.

I thought the problem with doing this is the engine needs more timing and therefore is actually less efficient? Modern engines need very little timing to get to MBT, those super sharp edges on the squish pads are probably not the right way to get there but doing away with it entirely doesn't sound right either.

Something strange I noticed is the squish pads on the cylinder head are missing. This doesn't seem super wise to do for a relatively street-oriented build? The shot of it is at 6:42. Does it look like they just machined it out for some reason? Surface finish is visibly different so my best guess is yes.

This SEMA has been interesting for product announcements. PRP finally got their cast block + head fully assembled for initial testing.

It's my experience that when cars get old enough every failure starts to be unique and surprising like this. They must be reading Anna Karenina or something.

https://nissan.epc-data.com/skyline/er34/3945-rb25det/trans/317/31940N/ The pictures of the part you're talking about is clearly not just one solenoid. You can see another picture of it here: https://www.alltranz.com.au/shop/drivetrain/automatic-transmission/RE5R01A/product/9305/ The 4 speed automatic in the GTT is Nissan corporate stuff. You can search up similar jobs done on a Frontier or Pathfinder with a RE4R01B to get an idea for what the internals are going to look like and the procedure like this:

Right, not sure why I thought it to be a lean spike. It might be fixable with modern card-style hot film MAFs which have some design features to avoid counting reversion flow but I've never tried it myself.

If you block off the BOV entirely you will get reversion out of the MAF and get a lean spike instead of a rich spike as the MAF double-counts the airflow.

These are sold all the time at Walmart and like others have said the angle is "more eco friendly". It is slightly cheaper. Oil-contaminated plastics cannot be recycled so less of it is better, but you need a whole bunch of extra stuff to handle this. You need probably one clean 5 quart oil jug you set aside to use as an intermediate holding tank. You need your local hazmat to return your oil catch pan AND you need to make sure whatever oil catch pan you use can hold engine oil without any risk of leaking during transport. Or you have dedicated used engine oil containers that your local curbside recycling will drain and return. Personally I have stuck to just buying 5 quart bottles because this is just too much mess to be worth the hassle.