joshuaho96

Kind of surprising that they start with fuel cut to a cylinder, I would have figured adjusting timing within a range would be the primary strategy. Maybe that causes excessive EGTs?

The QG18DE does have coolant in the intake manifold. Most QG18DEs do not have EGR, only California emissions models and comparably strict emissions regimes would have them. Even then none of them have an EGR cooler so no coolant would make it into the engine from the EGR system and it wouldn't get into the oil that way either, any more than you would from the intake manifold leaking. There is no coolant in the exhaust manifold or anything like that, this engine is pretty straightforward in that regard. Theoretically it is possible that your intake manifold is causing all of these issues but I kind of find it hard to believe. Pressurize the cooling system and see if you can hear that pressure coming from the intake manifold. Or get a camera snaked in there and see if there's coolant pooling in the intake manifold. You can also try pressurizing the cylinders, if you have a blown head gasket it should end up either in the valve cover or pushing out the radiator.

I’m pretty sure from what I recall of this if you bore to standard RB26 size the cylinder walls are no thicker than a normal RB. If you want a simple solution just get a PRP block whenever they release that.

The issues you're describing here is kind of why I want to have a fully integrated ECU. Also pulling fuel even if it's a hard cylinder cut seems unwise from a harmonics perspective. Maybe it's no worse than an I5 or I4 done right but I'd rather do DBW to control it. Boost by gear and tuning the power delivery can also help avoid generating all that boost/power your chassis realistically couldn't handle either.

At this point why bother trying to buy an R32 ECU + Nistune board + Nistune license when that gets you most of the way to a Haltech E2500 or Nexus R3? I'm probably biased though, I decided I would rather put the energy into trying to do a true port of the factory tune to Haltech rather than mess with Nistune.

When I searched up that part number it was literally a tube of Loctite 518 in a Nissan box. I'm just not sure what the difference is between 515 and 518. Both are anaerobic sealants with similar methacrylate base. As far as I can tell it's just a color difference and 515 needs a longer cure time.

AFAIK the OEM sealant is actually Loctite 518, listed as p/n C133531X25 if you buy it from Nissan. Checking online I do not see any paper gasket or anything like that for the actuator: https://nissan.epc-data.com/skyline/bcnr33/3935-rb26dett/trans/333/30570X/

Yes, you should be concerned. How concerned? Don't know. Poke a screwdriver and see how deep the rust goes. If it makes a hole you need to weld in new metal.

Yeah, plan is to run a bunch of sensors and try to develop a good tune + engine protection and do a lot of logging during track conditions to quantify things like what the stock sump can handle in terms of lat/lon g, then start empirically testing things like additional sump breathers/accusump to see how much it helps. I would rather not discover exactly how consumable a block can be but anything could happen really considering I've only done dry compression tests.

Probably not, but I'm planning on doing it every so often if only to verify the car doesn't fall apart in those conditions. Not sure how else I could test things like whether the oil system can handle the Gs and whether thermal management is good enough for extended track use. To really get extensive track time in I'd probably just buy a Miata or a Corvette instead of something that overheats within 5-10 minutes of hard track use stock. Sure, but seemingly half of the people in my area with Skylines have blown their engines and mired in that whole quagmire for years at a time. I'm pretty confident I still have all stock oil pan so that's going to be an ordeal I'm going to have to face at some point. Would really be nice if pulling the oil pan on the RB26 didn't require dropping the whole subframe out with the engine dangling precariously or pulling the engine out.

I've been told RBs snap cams and spin bearings if you look at them wrong so any day now I'm preparing for a big engine build.

Sure, but at some point I'm going to be in the market for a block regardless and stuff like that will be a dealbreaker regardless of whether I spend 10k or 50k or 80k on the whole package.

Yeah I'm not leaving a car idling for 12 minutes before driving it, even if I did that regularly I would want the option to be able to count 10 seconds and put it in gear. I would be afraid to forget and immediately trash my engine in the process.

AFAIK that's not called an AAC valve but rather an "intake air regulator". In Nissan's defense Toyota loved putting similar weird things on a lot of their cars, they just stopped doing it sooner than Nissan it seems.

You clearly have never seen Japanese mechanics in action then, they use RTV anywhere and everywhere. I hate using RTV because it requires more than zero skill to prep and apply it.

I could've waited months for everything to set, I just figured thread sealant didn't make sense because it wouldn't provide resistance/structure like teflon tape. Presumably I could've used thread sealant by just tightening to the same number of turns but it genuinely felt loose so I was worried it would work itself loose even if the thread sealant had set. Another person I saw working on this engine used RTV instead so clearly I was not the only person concerned about this fitting working itself loose, I just hate the idea of using something that would almost certainly make it incredibly annoying to remove in the future.

@R3N3 Not sure why I can't quote your post but I'm pretty sure the way it works is you need a resistor there to not have a dead short to ground if it grounds through the SRS ECU instead of the LED. That and you don't want to have the LED burn out from excessive current. The logic is probably that the SRS control unit needs to indicate at all times that the system is functioning to keep the malfunction light off. So presumably yes +12V needs to have a resistor in series with both the LED and SRS CU. Keep in mind I'm a mediocre electrical engineer at best so take with appropriate skepticism.

You guys sure you aren’t just agreeing on basically the same thing? Stock tune, stock engine within reason the Nissan tunes seem pretty safe. The RB26 out here runs ok on 91 AKI which is 95-96 RON. It’s when you run a Mines tune or whatever made for 100 RON super premium that you start seeing engines blow up. Personally I’m probably going to run wastegate boost and roughly stock timing forever on 91 AKI E10. It’s just terrible fuel and RBs are expensive to rebuild. I might play a bit with boost enrichment thresholds but that’s it. Any additional timing and boost I’d probably want at least E30.

You really need a diagnostic cable and logging of core ECU parameters to get to the bottom of this.

-4 psi sounds low for idle no? I'm used to seeing something like -9 psi. Obviously snapping the throttle shut coasting at 3000 RPM will pull it pretty close to full vacuum.

Dodge Demon owners and people who have tuned their engine around 100 octane and don’t want to keep 100 gallon drums in their garage. It’s not a big market but they can charge a decent markup on it. Substantially more expensive than 100LL by a long shot.

In my area it's something like 2.60 USD per liter for 100 octane street-legal race gas. E85 is substantially easier to find and often 30% cheaper than premium unleaded pump gas so if you can afford to convert to flex fuel instead it is much, much cheaper to run than proper 100 AKI. You can also adjust your ethanol mix to find the minimum ethanol percentage needed to balance between range and octane.

AFAIK you can get around some of the Haltech vendor lock-in but you have to be willing to put in work to reverse engineer things. I did this recently for the AMP Superseal 1.0 connectors. If there's interest I can post up all the little things I learn along the way. If you want "modern -5s" AFAIK the GTX2860R gen 2 is available in bolt-on form for the RB26. Speed Academy ran them but I'm not sure the results are all that impressive. A lot of this is probably because the factory piping is just restrictive.

I think your idea of "not huge power" vs my idea of "not huge power" is very different. 2867s are big turbos and arguably too big for the factory twin turbo setup. If you want to stay with factory twin turbo to reduce the amount of unknowns in your build I wouldn't go larger than 2860s. Especially if reliability is a concern at all.

It isn’t absolute no but I wouldn’t want to install one that indicates excessive shock. And I’m not sure a used one is a good idea anyways, the springs and pots in there have probably aged significantly. Modern MEMS like the Do-Luck or Midori Seibi sensor are the way to go IMO.