joshuaho96

Even with E85 if you've tuned to the knock limit TJI should allow for even more margin if it works and it should, emphasis on should, just be a set of plugs and a retune. I would pass on being the first to buy this engine, just the tubular manifolds suggests to me that either this is a prototype or they don't expect to sell many of these "vertical turbos". Maserati seems to have decided that a pre-chamber plugs alone are not good enough for idle/low load which makes me wonder how HKS plans to make a single pre-chamber plug work for all load/RPM/coolant temperatures. I currently have my hands full just trying to get my car registered properly and through CA emissions right now, maybe a few years down the road we'll see what actually endures and ships instead of being a cool model and marketing slide deck. A lot of bits and pieces on my car to focus on before fixing what isn't broken.

Is anyone else planning on trying to get TJI working on an RB26? I think that piece alone would allow for quite substantial gains in knock margin. Mahle has a marketing summary here: https://www.mahle-powertrain.com/media/mahle-powertrain/experience/mahle-jet-ignition/mahle-jet-ignition-product-information.pdf "Stoichiometric operation (λ≈1.0) (conventional after-treatment utilised) • Rapid, stable combustion enables high dilution tolerance allowing high EGR rates • Enhanced efficiency and λ≈1.0 operation at high loads • Compatible with Miller-cycle operation • Knock reduction (enables high CR operation)"

Looks like HKS is floating the idea of retrofitting TJI and reverse flow turbos to the RB26 to improve the packaging with twin turbos. Dual chamber plenum too, to try and improve airflow distribution between the cylinders. Dual injectors to be able to use single cone injectors while reducing fuel impingement on the cylinder head walls. Not mentioned in the video but seemingly also present on the engine are their R35 coil retrofit, cam/crank trigger kit, and exhaust VCAM. I'm sure that engine is probably going to cost as much as the entire car itself if they ever sell it as a complete package.

Pretty much every R33 I see is in need of major rust repairs these days, whether it's the frame itself that is rotting out or the subframes.

I'm in the US, my concern is that the gas strut is too strong. The Alibaba generic one is said to be more appropriate, so I'm thinking of trying one of those first.

Did this work out properly? I need a replacement for the trunk gas strut as well.

How old are you? It sounds like you are not yet at a point in your life where you can make your own financial decisions. Focus on fixing that part first, worry about the Skyline later.

That's a fixed 16 degree advance, even VCAM Step 1 allows for variable 30 degree cam advance. If it didn't make a big difference Nissan wouldn't have implemented continuous VVT in the VR and VQ engines.

Those are definitely halogens, so just use those and retrofit a halogen low beam projector. Leave the high beams alone, those are universal.

You have to convert to LHD, not RHD. The headlights are RHD/LHT from the factory. Here's a pdf guide for the conversion, pdf warning: https://wardiz.org/blog/wp-content/uploads/2011/04/R33-Projector-Headlamps-Tutorial.pdf For those that are not bound by issues like TUV compliance you can have the series 3 HIDs modified to produce an LHD beam pattern like this:

https://clubgrandtouring.wordpress.com/2020/08/11/what-do-the-f40-and-the-bcnr33-have-in-common/ It's normal.

Look at the spectrograph view, if turning down the timing has no visible change in the knock sensor (and you know the knock sensor signal is good) then it's probably calibrated wrong.

R34 VSpec 1 and VSpec 2 do not have the same part number for headlight housings. Not sure where you got that. "Housing assembly" is the part you're talking about, "Headlight Assembly" includes things like the HID ballast, bulb caps, bulbs, etc. Whether you need a housing assembly or a headlight assembly depends on what's wrong with the headlight. You may not even need a housing assembly if your problem is just that the lens is damaged. If you want to swap to Xenon from Halogen then you will want an entire headlight assembly. I believe the difference between the 1999-2000 headlight assembly vs 2000+ headlight assembly is this: "Xenon headlamps change from Series 1 cars to Series 2 cars. Series 2 cars (lense code 1618) have shadow chrome inserts as opposed to champagne accents on the Series 1 (lense code 1601) cars. Series 2 cars lost the light level actuator motors from housings activated via cabin switch." Source: http://gtr-registry.com/en-bnr34-specs.php There may be smaller differences though. I suspect this is why the some housings are half the price of others.

https://prestigemotorsport.com.au/import-early-build-r35-gtr-from-2019/?fbclid=IwAR0jNtvFhRqoKozqtkl4CIHATNoiNRaASE4HF045jPAFqGFz7-F3sr344Ew Looks like early builds can be done, but those aren't as desirable as the DBAs.

Haltech seems to have automatic transmission support now, it's noted for the Y60/Y61 Elite adapter harness: https://www.haltech.com/overview-plugnplay-adaptor-nissan-patrol-y6061-tb4245/ They have online documentation here: https://support.haltech.com/portal/en/kb/articles/transmission-control

Maybe, but load is measured based on a completely arbitrary MAF VQ. I’m manually doing the VQ to grams per second unit conversion. Even if you don’t bother with that there’s still a huge delta between deriving TP via VQ, Kconst, and RPM and what the ECU reports as TP. I suspect that much like how the MAF VQ units are arbitrary to fit the size of the ADC output, Nissan was likely doing some internal rescaling to get the load index to be an 8 bit integer and TP to fit in a 16 bit integer. Internal tooling could easily handle this weirdness while still showing sane units to anyone working on the engine calibration. Talking to Matt at Nistune he also suspects that this is just some bit twiddling done to make the scaling fit. It’s not documented in Nissan’s patent on their ECUs of the era which makes me think it’s an implementation detail.

For those that are interested in the original problem, I found some logs of a stock R32 GTR running Nistune and concluded that it's a roughly 23.5 or 23.6x factor that is hidden in the TP calculations. So instead of this: TP = (Kconst * VQ) / RPM It's actually something like this: TP = (Kconst * VQ * 23.6) / RPM Here's my work, gathered by going through this Nistune post: https://forum.nistune.com/viewtopic.php?f=8&t=3655 The header is not quite as helpful as I would hope but basically the first 4 columns are straight from the logs and TP less K is effectively the expected VQ/RPM value, while VQ and VQ/RPM headers are the interpolated VQ value measured from MAF voltage and VQ/RPM is that VQ value divided by the RPM in that part of the log. The two methods arrive at vastly different numbers, so the ~23.6x factor I mentioned is how I reconcile the two. Edit: What's remarkable about this is actually how close the TP index is to the total airflow to the engine, in grams per cylinder, just with fewer significant digits.

My understanding was that if you adjust K at all or changed the MAFs you've effectively rescaled the ignition and fuel maps, even if the math still works out such that the ECU stays within the OEM load scale. I really just want to ensure that I keep the factory fuel targets/ignition timing in real load + RPM, so that the behavior is going to be the same as stock if I don't modify them. Maybe pointless but I'm trying to make sure that I don't change too many variables all at the same time.

I’m aware that general practice is to not bother with trying to do this, I just want to make sure that messing with K and VQ that I rescale the maps correctly. Getting down to raw physical units helps because the VQ scale is not a linear factor.

I'm trying to understand how a stock BNR32 ECU calculates TP load on the primary fuel/ignition maps. I read through the Nistune manual to find the following equation: TP = (VQ * Kconst) / RPM TP load index = TP / 256 I looked up the MAF VQ (voltage quantifier) curve in the base BNR32 ECU's MAF table and referenced it against Haltech's RB26 stock MAF curve. From this I concluded that the VQ curve is such that 1 VQ unit is equal to roughly 0.005152 grams per second of mass flow. This constant produces a curve that makes the Nistune and Haltech curves agree almost perfectly. The only error I see with this method is below 1 g/s, so with two MAFs at roughly the same flow rate that's likely below the minimum airflow at idle: From there I tried to reverse the TP load index equation to get some sort of estimate for grams per cylinder. Something I noticed reading the tables is that there is a fuel cut that occurs above a load index of 160, which suggests to me that the load index of the OEM tables should never exceed 80 and the final load row of 88 is just a failsafe. I tried the following to convert this TP load index into grams of air per cylinder: TP_load * 256 * Kconst * 60 = VQ/RPS Where TP_load is 80, Kconst is 233 (defined by the ECU), and 60 is a constant to convert RPM to RPS. From there we can convert VQ into a grams per second value like this: TP_load * 256 * Kconst * 60 * 0.005152 = (g/s) / RPS The seconds cancel out, so this is actually a grams of air per revolution value. Every revolution half of the cylinders are intaking air because it's a 4 stroke engine, so we can divide this number by 3 to get grams of air per cylinder. The problem is that when I do this math I get a figure of ~27 grams of air per revolution. At the power peak of ~6800 rpm stock that implies the "peak load" limit corresponds to roughly 3000 grams per second of air mass metered by a single MAF. A single MAF can only meter about 150 grams of air per second before it maxes out. So I'm off by a factor of 20 which is definitely wrong. Anyone know if I just suck at math? Or if I'm missing a bunch of extra bits to how TP is calculated? If anyone has a Nistune log of MAF VQ, RPM, and TP on a stock RB26 + stock tune I would really love to see it.

Step one is probably sell the car and get an AWD variant because you need a big divot in the floor pan to fit the transfercase.

I flipped it backwards, -5s are too big, correct. But GT3-SS turbos are tiny, 0.54 a/r exhaust turbine which is tighter than any other turbo out there. They nose over hard on 2.6, so the concern is that a 2.8 will just shift everything down a few hundred RPM and make the engine feel like a Mazda 2.5T where the power falls off a cliff well before redline. The HKS turbos may be a waste of time/money but it's already too late, the turbos are bought for and installed so I'm just going to see how they go. The engine isn't at the point where the bottom end is going to be taken apart yet so it's going to just be a 2.6 for now. I have a VCAM step 1 sitting in the garage so that can be a first attempt to try and get the VE up earlier to spool the turbos. If that doesn't get the desired powerband then I'll think about a stroker or RB26/30. I'll post dyno charts and data logs as I work through this, if it sucks you guys can have some fun pointing and laughing.

No, but I'd rather not spend 5000 USD on a stroker kit only to discover that the engine peaks in power undesirably early. -5s are too small for 2.6L, but the GT3-SS is so small that it has trouble holding boost out to 7000 RPM even with 2.6L. I have a feeling that if you stroke it out to 2.8L it's going to be even worse in that regard.

Gran Turismo Sport seems to do a pretty good job of simulating the R32/R33/R34 GT-Rs.

I was under the impression that if a turbo is already choking the engine above a certain RPM, additional displacement would just shift the power curve down some amount of RPM. Is this not the case?